95,497 results on '"Varga, A"'
Search Results
2. Victor Hugo et l’art de convaincre - Le récit hugolien: rhétorique, argumentation, persuasion par Albert W. Halsall (review)
- Author
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Varga, Áron Kibédi
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- 2023
- Full Text
- View/download PDF
3. Cooperative Trajectory Planning: Principles for Human-Machine System Design on Trajectory Level
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Schneider, Julian, Varga, Balint, and Hohmann, Sören
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Electrical Engineering and Systems Science - Systems and Control - Abstract
This paper explores cooperative trajectory planning approaches within the context of human-machine shared control. In shared control research, it is typically assumed that the human and the automation use the same reference trajectory to stabilize the coupled system. However, this assumption is often incorrect, as they usually follow different trajectories, causing control conflicts at the action level that have not been widely researched. To address this, it is logical to extend shared control concepts to include human-machine interaction at the trajectory-level before action execution, resulting in a unified reference trajectory for both human and automation. This paper begins with a literature overview on approaches of cooperative trajectory planning. It then presents an approach of finding a joint trajectory by modelling cooperative trajectory planning as an agreement process. A generally valid system structure is proposed for this purpose. Finally, it proposes concepts to implement cooperative trajectory planning as an agreement process.
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- 2024
4. CH(A) Radical Formation in Coulomb Explosion from Butane Seeded Plasma Generated with Chirp-Controlled Ultrashort Laser Pulses
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Mogyorosi, Karoly, Toth, Balint, Sarosi, Krisztina, Gilicze, Barnabas, Csontos, Janos, Somoskoi, Tamas, Toth, Szabolcs, Geetha, Prabhash Prasannan, Toth, Laszlo, Taylor, Samuel S., Skoufis, Nicholas, Barron, Liam, Varga, Kalman, Covington, Cody, and Chikan, Viktor
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Physics - Chemical Physics ,Physics - Plasma Physics - Abstract
We experimentally studied the formation of CH(A) radicals in butane seeded plasma generated with chirp-controlled ultrashort laser pulses (\(\sim 760 \, \mu \text{J}/\text{pulse}\), 890 nm, 1 kHz, 8 fs). The focused beam with high peak intensity (\(\sim 10^{14} - 10^{16} \, \text{W/cm}^2\)) caused Coulomb explosion (CE). The time dependent emission spectra were observed with the Fourier-transform Visible spectroscopy (FTVis) step-scan method. The average signal intensity decreased with the chirp in the Ar\(^+\) > C\(_2\) > H-\(\alpha\) \(\sim\) CH(A) order with a plateau for CH(A) in the \(-200\) to \(-100 \, \text{fs}^2\) range. The short rise time of the CH(A) emission signal, the monoexponential emission decay, and the nearly constant rotational and vibrational temperatures of the CH(A) radicals (\(\sim 3000 \, \text{K}\) and \(\sim 3800 \, \text{K}\)) all support their formation as a primary product. Our TDDFT calculations predict that CH and many other fragments can be formed beyond CE at \(\sim 7 \times 10^{14} \, \text{W/cm}^2\) intensity. The average charge of CH (+0.6) and its relative abundance (0.5\%) support the formation of detectable CH(A) within 120 fs.
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- 2024
5. Fragmentation in Coulomb explosion of hydrocarbon molecules
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Taylor, Samuel S., Varga, Kálmán, Mogyorósi, Károly, Chikán, Viktor, and Covington, Cody
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Physics - Chemical Physics - Abstract
Fragmentation dynamics in the Coulomb explosion of hydrocarbons, specifically methane, ethane, propane, and butane, are investigated using time dependent density functional theory (TDDFT) simulations. The goal of this work is to elucidate the distribution of fragments generated under laser-driven Coulomb explosion conditions. Detailed analysis reveals the types of fragments formed, their respective charge states, and the optimal laser intensities required for achieving various fragmentations. Our results indicate distinct fragmentation patterns for each hydrocarbon, correlating with the molecular structure and ionization potential. Additionally, we identify the laser parameters that maximize fragmentation efficiency, providing valuable insights for experimental setups. This research advances our understanding of Coulomb explosion mechanisms and offers a foundation for further studies in controlled molecular fragmentation.
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- 2024
6. Walking the Line: Young Stars on the Boundary of the Epsilon Cha and Lower Centaurus-Crux Associations
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Varga, Attila, Kastner, Joel H., Dickson-Vandervelde, D. Annie, and Binks, Alex S.
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Astrophysics - Solar and Stellar Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
Gaia Data Release 3 (DR3) has provided the largest and most astrometrically precise catalogue of nearby stars to date, allowing for a more complete membership census of nearby, young stellar moving groups. These loose associations of young (age $<$100 Myr) stars within $\sim$100 pc are vital laboratories for the study of the early evolution of low-mass stars and planetary systems. We have exploited DR3 data to examine the boundary region between two of the youngest nearby moving groups, the $\sim$3--8 Myr-old $\epsilon$ Cha Association (ECA) and an $\sim$8 Myr-old sub-population of the sprawling Lower Centaurus Crux (LCC) young star complex. Using spatio-kinematic and color-magnitude criteria designed to select stars in the ECA, we identify $\sim$54 new young-star candidates that extend from the ECA core to the southern edge of the LCC. Included among our new candidates are six previously unidentified ultra-low-mass, mid- to late-M stars, lying near the future hydrogen-burning limit, that display significant infrared excesses. Our spatial, kinematic, and CMD analysis of these new candidates and previously established LCC and ECA members blurs the boundary between these groups and provides evidence for a wave of continuous star formation extending from north (LCC) to south (ECA). We discuss the factors which studies of nearby young moving groups must consider when constraining the ages of stars in these groups., Comment: Accepted by AJ
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- 2024
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7. Measuring Research Interest Similarity with Transition Probabilities
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Varga, Attila, Kojaku, Sadamori, and Silva, Filipi Nascimento
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Computer Science - Digital Libraries ,Computer Science - Social and Information Networks ,Statistics - Applications - Abstract
We propose a method to measure the similarity of papers and authors by simulating a literature search procedure on citation networks, which is an information retrieval inspired conceptualization of similarity. This transition probability (TP) based approach does not require a curated classification system, avoids clustering complications, and provides a continuous measure of similarity. We perform testing scenarios to explore several versions of the general TP concept and the Node2vec machine-learning technique. We found that TP measures outperform Node2vec in mapping the macroscopic structure of fields. The paper provides a general discussion of how to implement TP similarity measurement, with a particular focus on how to utilize publication-level information to approximate the research interest similarity of individual scientists. This paper is accompanied by a Python package capable of calculating all the tested metrics.
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- 2024
8. Social impact of CAVs -- coexistence of machines and humans in the context of route choice
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Jamróz, Grzegorz, Akman, Ahmet Onur, Psarou, Anastasia, Varga, Zoltán Györgi, and Kucharski, Rafał
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Computer Science - Multiagent Systems - Abstract
Suppose in a stable urban traffic system populated only by human driven vehicles (HDVs), a given proportion (e.g. 10%) is replaced by a fleet of Connected and Autonomous Vehicles (CAVs), which share information and pursue a collective goal. Suppose these vehicles are centrally coordinated and differ from HDVs only by their collective capacities allowing them to make more efficient routing decisions before the travel on a given day begins. Suppose there is a choice between two routes and every day each driver makes a decision which route to take. Human drivers maximize their utility. CAVs might optimize different goals, such as the total travel time of the fleet. We show that in this plausible futuristic setting, the strategy CAVs are allowed to adopt may result in human drivers either benefitting or being systematically disadvantaged and urban networks becoming more or less optimal. Consequently, some regulatory measures might become indispensable.
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- 2024
9. Universality of the close packing properties and markers of isotropic-to-tetratic phase change in quasi-one-dimensional superdisk fluid
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Mizani, Sakineh, Oettel, Martin, Gurin, Péter, and Varga, Szabolcs
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Condensed Matter - Soft Condensed Matter - Abstract
We study equilibrium states and phases of a quasi-one-dimensional system of hard superdisks (anisotropic particles interpolating between disks and squares) where the centers of the particles are constrained to move on a line. A continuous change from a quasi-isotropic to a tetratic phase is found upon increasing the density. Somewhat unexpected, for isobaric states, systems with larger and more anisotropic particles in the tetratic phase are denser than systems with smaller and less anisotropic particles in a quasi-isotropic phase. Close packing behaviour is characterised by exponents describing the behaviour of the pressure, the angular fluctuations and the angular correlation length. We obtain two universal, shape-independent relations between them., Comment: Submission to SciPost
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- 2024
10. Piercing intersecting convex sets
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Bárány, Imre, Dillon, Travis, Pálvölgyi, Dömötör, and Varga, Dániel
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Mathematics - Combinatorics - Abstract
Assume two finite families $\mathcal A$ and $\mathcal B$ of convex sets in $\mathbb{R}^3$ have the property that $A\cap B\ne \emptyset$ for every $A \in \mathcal A$ and $B\in \mathcal B$. Is there a constant $\gamma >0$ (independent of $\mathcal A$ and $\mathcal B$) such that there is a line intersecting $\gamma|\mathcal A|$ sets in $\mathcal A$ or $\gamma|\mathcal B|$ sets in $\mathcal B$? This is an intriguing Helly-type question from a paper by Mart\'{i}nez, Roldan and Rubin. We confirm this in the special case when all sets in $\mathcal A$ lie in parallel planes and all sets in $\mathcal B$ lie in parallel planes; in fact, all sets from one of the two families has a line transversal.
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- 2024
11. Exploring 30 Years of Research in Learning Technology: An Analysis of the RLT Journal
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Julie Voce, Liz Bennett, James Brunton, Evana Downes Rolewicz, Michael Flavin, Sarah Honeychurch, and Tünde Varga-Atkins
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This paper presents the findings from a research project to analyse 30 years of the "Research in Learning Technology" journal (1993 to 2022). The analysis explores the content of the articles in terms of key topics and their relationship with sector events and policies, discussing key terms such as virtual learning environment, massive open online courses (MOOCs) and virtual reality (VR). It also considers how the terminology used to describe the field has changed over time, starting with a focus on the computer and expanding to include a range of common terms such as e-learning, technology enhanced learning (TEL) and digital. Between 1993 and 2015, issues of the journal were accompanied by editorials. This analysis considers how the role of the editorials helped to shape and establish the journal and influence the field of learning technology to take a more research and theory-based approach. Finally, an analysis of the locations of the authors who have published in the journal has demonstrated a shift from a predominantly UK-based journal to one with more international reach.
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- 2024
12. Gender Disparities and Potentials in STEM Approach in Jordan and Saudi Arabia -- An Analytical Literature Review
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Jehan Alghneimin, Attila Varga, and Monika Kovacs
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In recent years, the integrated approach of STEM disciplines (Science, Technology, Engineering, and Mathematics) has been adopted in the Middle East to improve students' scientific capacities and their formative thinking. Nevertheless, this approach encounters complications in the application, including many due to gender differences. Middle Eastern women's life and education is affected by conservative constraints and social norms where gender stereotypes and culture impact shared views about specific domains. Research regarding gender has frequently emphasized gender imbalance in virtually all STEM study fields and professions. This study explores STEM education's conceptual framework in Jordan and Saudi Arabia. Likewise, it provides an overview of STEM teachers' practices and their gender perspectives in the classrooms. We investigate the implementations and gender differences in STEM education by scrutinizing relevant literature and studies in the selected countries. The conclusions indicate a shortage of teachers' knowledge in applying STEM education in classrooms and a need for more development programs that qualify teachers for STEM education applications. In addition, the results show that gender disparities are promoted by the education system and teachers who teach STEM subjects in schools because social norms and gender stereotypes influence them.
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- 2024
13. Demonstration of strong coupling of a subradiant atom array to a cavity vacuum
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Gábor, Bence, Adwaith, K. V., Varga, Dániel, Sárközi, Bálint, Dombi, András, Clark, T. W., Williams, F. I. B., Nagy, David, Vukics, András, and Domokos, Peter
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Quantum Physics ,Physics - Atomic Physics ,Physics - Optics - Abstract
By considering linear scattering of cold atoms inside an undriven high-finesse optical resonator, we experimentally demonstrate effects unique to a strongly coupled vacuum field. Arranging the atoms in an incommensurate lattice, with respect to the resonator mode, the scattering can be suppressed by destructive interference: resulting in a subradiant atomic array. We show however, that strong coupling leads to a drastic modification of the excitation spectrum, as evidenced by well-resolved vacuum Rabi splitting in the intensity of the fluctuations. Furthermore, we demonstrate a significant polarization rotation in the linear scattering off the subradiant array via Raman scattering induced by the strongly coupled vacuum field.
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- 2024
14. Event-activity-dependent beauty-baryon enhancement in simulations with color junctions
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Földvári, Lea Virág, Varga, Zoltán, and Vértesi, Róbert
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High Energy Physics - Phenomenology ,Nuclear Experiment - Abstract
Recent results from ALICE and CMS show a low-transverse-momentum enhancement of charm baryon-to-meson production ratios over model predictions based on e$^+$e$^-$ collisions. Several mechanisms are proposed to understand this phenomenon. New measurements by the LHCb and ALICE experiments show a similar enhancement in the beauty sector. We explore this enhancement in terms of event activity using the color-reconnection beyond leading order approximation model. We propose sensitive probes relying on the event shape that will allow for the differentiation between the proposed beauty-production scenarios using freshly collected LHC Run-3 data, and we also compare these to predictions for charm. Our results will contribute to a deeper theoretical understanding of the heavy-flavor baryon enhancement and its relation to baryon enhancement in general., Comment: Submiited to IJMPA Special Issue Zim\'anyi School 2023
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- 2024
15. Ejecta masses in Type Ia Supernovae -- Implications for the Progenitor and the Explosion Scenario
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Bora, Zsófia, Könyves-Tóth, Réka, Vinkó, József, Bánhidi, Dominik, Bíró, Imre Barna, Bostroem, K. Azalee, Bódi, Attila, Burke, Jamison, Csányi, István, Cseh, Borbála, Farah, Joseph, Filippenko, Alexei V., Hegedűs, Tibor, Hiramatsu, Daichi, Horti-Dávid, Ágoston, Howell, D. Andrew, Jha, Saurabh W., Kalup, Csilla, Krezinger, Máté, Kriskovics, Levente, McCully, Curtis, Newsome, Megan, Ordasi, András, Gonzalez, Estefania Padilla, Pál, András, Pellegrino, Craig, Seli, Bálint, Sódor, Ádám, Szabó, Zsófia Marianna, Szabó, Norton O., Szakáts, Róbert, Szalai, Tamás, Székely, Péter, Terreran, Giacomo, Varga, Vázsony, Vida, Krisztián, Wang, Xiaofeng, and Wheeler, J. Craig
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Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Solar and Stellar Astrophysics - Abstract
The progenitor system(s) as well as the explosion mechanism(s) of thermonuclear (Type Ia) supernovae are long-standing issues in astrophysics. Here we present ejecta masses and other physical parameters for 28 recent Type Ia supernovae inferred from multiband photometric and optical spectroscopic data. Our results confirm that the majority of SNe Ia show {\it observable} ejecta masses below the Chandrasekhar-limit (having a mean $M_{\rm ej} \approx 1.1 \pm 0.3$ M$_\odot$), consistent with the predictions of recent sub-M$_{\rm Ch}$ explosion models. They are compatible with models assuming either single- or double-degenerate progenitor configurations. We also recover a sub-sample of supernovae within $1.2 $ M$_\odot$ $< M_{\rm {ej}} < 1.5$ M$_\odot$ that are consistent with near-Chandrasekhar explosions. Taking into account the uncertainties of the inferred ejecta masses, about half of our SNe are compatible with both explosion models. We compare our results with those in previous studies, and discuss the caveats and concerns regarding the applied methodology.
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- 2024
16. Study on Human-Variability-Respecting Optimal Control Affecting Human Interaction Experience
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Kille, Sean, Varga, Balint, and Hohmann, Sören
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Electrical Engineering and Systems Science - Systems and Control - Abstract
Broad application of human-machine interaction (HMI) demands advanced and human-centered control designs for the machine's automation. Human natural motor action shows stochastic behavior, which has so far not been respected in HMI control designs. Using a previously presented novel human-variability-respecting optimal controller we present a study design which allows the investigation of respecting human natural variability and its effect on human interaction experience. Our approach is tested in simulation based on an identified real human subject and presents a promising approach to be used for a larger subject study.
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- 2024
17. Complexity of two-level systems
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Varga, Imre
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Quantum Physics ,Condensed Matter - Other Condensed Matter ,Condensed Matter - Statistical Mechanics ,Nonlinear Sciences - Chaotic Dynamics - Abstract
Complexity of two-level systems, e.g. spins, qubits, magnetic moments etc, are analysed based on the so-called correlational entropy in the case of pure quantum systems and the thermal entropy in case of thermal equilibrium that are suitable quantities essentially free from basis dependence. The complexity is defined as the difference between the Shannon-entropy and the second order R\'enyi-entropy, where the latter is connected to the traditional participation measure or purity. It is shown that the system attains maximal complexity for special choice of control parameters, i.e. strength of disorder either in the presence of noise of the energy states or the presence of disorder in the off diagonal coupling. It is shown that such a noise or disorder dependence provides a basis free analysis and gives meaningful insights. We also look at similar entropic complexity of spins in thermal equilibrium for a paramagnet at finite temperature, $T$ and magnetic field $B$, as well as the case of an Ising model in the mean-field approximation. As a result all examples provide important evidence that the investigation of the entropic complexity parameters help to get deeper understanding in the behavior of these systems., Comment: 9 pages, 9 figures
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- 2024
18. Enhancing weak lensing redshift distribution characterization by optimizing the Dark Energy Survey Self-Organizing Map Photo-z method
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Campos, A., Yin, B., Dodelson, S., Amon, A., Alarcon, A., Sánchez, C., Bernstein, G. M., Giannini, G., Myles, J., Samuroff, S., Alves, O., Andrade-Oliveira, F., Bechtol, K., Becker, M. R., Blazek, J., Camacho, H., Rosell, A. Carnero, Kind, M. Carrasco, Cawthon, R., Chang, C., Chen, R., Choi, A., Cordero, J., Davis, C., DeRose, J., Diehl, H. T., Doux, C., Drlica-Wagner, A., Eckert, K., Eifler, T. F., Elvin-Poole, J., Everett, S., Fang, X., Ferté, A., Friedrich, O., Gatti, M., Gruen, D., Gruendl, R. A., Harrison, I., Hartley, W. G., Herner, K., Huang, H., Huff, E. M., Jarvis, M., Krause, E., Kuropatkin, N., Leget, P. -F., MacCrann, N., McCullough, J., Navarro-Alsina, A., Pandey, S., Prat, J., Raveri, M., Rollins, R. P., Roodman, A., Rosenfeld, R., Ross, A. J., Rykoff, E. S., Sanchez, J., Secco, L. F., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Troxel, M. A., Tutusaus, I., Varga, T. N., Wechsler, R. H., Yanny, B., Zhang, Y., Zuntz, J., Aguena, M., Annis, J., Bacon, D., Bocquet, S., Brooks, D., Burke, D. L., Carretero, J., Castander, F. J., Costanzi, M., da Costa, L. N., De Vicente, J., Doel, P., Ferrero, I., Flaugher, B., Frieman, J., García-Bellido, J., Gaztanaga, E., Gutierrez, G., Hinton, S. R., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Lima, M., Lin, H., Marshall, J. L., Mena-Fernández, J., Menanteau, F., Miquel, R., Ogando, R. L. C., Paterno, M., Pereira, M. E. S., Pieres, A., Malagón, A. A. Plazas, Porredon, A., Sanchez, E., Cid, D. Sanchez, Smith, M., Suchyta, E., Swanson, M. E. C., Tarle, G., To, C., Vikram, V., and Weaverdyck, N.
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Astrophysics - Cosmology and Nongalactic Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
Characterization of the redshift distribution of ensembles of galaxies is pivotal for large scale structure cosmological studies. In this work, we focus on improving the Self-Organizing Map (SOM) methodology for photometric redshift estimation (SOMPZ), specifically in anticipation of the Dark Energy Survey Year 6 (DES Y6) data. This data set, featuring deeper and fainter galaxies than DES Year 3 (DES Y3), demands adapted techniques to ensure accurate recovery of the underlying redshift distribution. We investigate three strategies for enhancing the existing SOM-based approach used in DES Y3: 1) Replacing the Y3 SOM algorithm with one tailored for redshift estimation challenges; 2) Incorporating $\textit{g}$-band flux information to refine redshift estimates (i.e. using $\textit{griz}$ fluxes as opposed to only $\textit{riz}$); 3) Augmenting redshift data for galaxies where available. These methods are applied to DES Y3 data, and results are compared to the Y3 fiducial ones. Our analysis indicates significant improvements with the first two strategies, notably reducing the overlap between redshift bins. By combining strategies 1 and 2, we have successfully managed to reduce redshift bin overlap in DES Y3 by up to 66$\%$. Conversely, the third strategy, involving the addition of redshift data for selected galaxies as an additional feature in the method, yields inferior results and is abandoned. Our findings contribute to the advancement of weak lensing redshift characterization and lay the groundwork for better redshift characterization in DES Year 6 and future stage IV surveys, like the Rubin Observatory.
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- 2024
19. Detecting Causality in the Frequency Domain with Cross-Mapping Coherence
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Benkő, Zsigmond, Varga, Bálint, Stippinger, Marcell, and Somogyvári, Zoltán
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Computer Science - Machine Learning ,Nonlinear Sciences - Chaotic Dynamics ,Physics - Data Analysis, Statistics and Probability ,Statistics - Machine Learning ,J.2 ,J.3 ,I.5 - Abstract
Understanding causal relationships within a system is crucial for uncovering its underlying mechanisms. Causal discovery methods, which facilitate the construction of such models from time-series data, hold the potential to significantly advance scientific and engineering fields. This study introduces the Cross-Mapping Coherence (CMC) method, designed to reveal causal connections in the frequency domain between time series. CMC builds upon nonlinear state-space reconstruction and extends the Convergent Cross-Mapping algorithm to the frequency domain by utilizing coherence metrics for evaluation. We tested the Cross-Mapping Coherence method using simulations of logistic maps, Lorenz systems, Kuramoto oscillators, and the Wilson-Cowan model of the visual cortex. CMC accurately identified the direction of causal connections in all simulated scenarios. When applied to the Wilson-Cowan model, CMC yielded consistent results similar to spectral Granger causality. Furthermore, CMC exhibits high sensitivity in detecting weak connections, demonstrates sample efficiency, and maintains robustness in the presence of noise. In conclusion, the capability to determine directed causal influences across different frequency bands allows CMC to provide valuable insights into the dynamics of complex, nonlinear systems.
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- 2024
20. Weak Gravitational Lensing around Low Surface Brightness Galaxies in the DES Year 3 Data
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Chicoine, N., Prat, J., Zacharegkas, G., Chang, C., Tanoglidis, D., Drlica-Wagner, A., Anbajagane, D., Adhikari, S., Amon, A., Wechsler, R. H., Alarcon, A., Bechtol, K., Becker, M. R., Bernstein, G. M., Campos, A., Rosell, A. Carnero, Kind, M. Carrasco, Cawthon, R., Chen, R., Choi, A., Cordero, J., Davis, C., DeRose, J., Dodelson, S., Doux, C., Eckert, K., Elvin-Poole, J., Everett, S., Ferté, A., Gatti, M., Giannini, G., Gruen, D., Gruendl, R. A., Harrison, I., Herner, K., Jarvis, M., Leget, P. -F., MacCrann, N., McCullough, J., Myles, J., Navarro-Alsina, A., Pandey, S., Raveri, M., Rollins, R. P., Roodman, A., Ross, A. J., Rykoff, E. S., Sánchez, C., Secco, L. F., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Troxel, M. A., Tutusaus, I., Varga, T. N., Yanny, B., Yin, B., Zuntz, J., Aguena, M., Alves, O., Bacon, D., Brooks, D., Carretero, J., Castander, F. J., Conselice, C., Desai, S., De Vicente, J., Doel, P., Ferrero, I., Flaugher, B., Frieman, J., García-Bellido, J., Gaztanaga, E., Gutierrez, G., Hinton, S. R., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Lee, S., Lidman, C., Lima, M., Marshall, J. L., Mena-Fernández, J., Miquel, R., Muir, J., Ogando, R. L. C., Palmese, A., Pereira, M. E. S., Pieres, A., Malagón, A. A. Plazas, Porredon, A., Walker, A. R., Samuroff, S., Sanchez, E., Cid, D. Sanchez, Smith, M., Suchyta, E., Swanson, M. E. C., Tarle, G., To, C., Tucker, D. L., Vikram, V., Weaverdyck, N., and Wiseman, P.
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Astrophysics - Astrophysics of Galaxies - Abstract
We present galaxy-galaxy lensing measurements using a sample of low surface brightness galaxies (LSBGs) drawn from the Dark Energy Survey Year 3 (Y3) data as lenses. LSBGs are diffuse galaxies with a surface brightness dimmer than the ambient night sky. These dark-matter-dominated objects are intriguing due to potentially unusual formation channels that lead to their diffuse stellar component. Given the faintness of LSBGs, using standard observational techniques to characterize their total masses proves challenging. Weak gravitational lensing, which is less sensitive to the stellar component of galaxies, could be a promising avenue to estimate the masses of LSBGs. Our LSBG sample consists of 23,790 galaxies separated into red and blue color types at $g-i\ge 0.60$ and $g-i< 0.60$, respectively. Combined with the DES Y3 shear catalog, we measure the tangential shear around these LSBGs and find signal-to-noise ratios of 6.67 for the red sample, 2.17 for the blue sample, and 5.30 for the full sample. We use the clustering redshifts method to obtain redshift distributions for the red and blue LSBG samples. Assuming all red LSBGs are satellites, we fit a simple model to the measurements and estimate the host halo mass of these LSBGs to be $\log(M_{\rm host}/M_{\odot}) = 12.98 ^{+0.10}_{-0.11}$. We place a 95% upper bound on the subhalo mass at $\log(M_{\rm sub}/M_{\odot})<11.51$. By contrast, we assume the blue LSBGs are centrals, and place a 95% upper bound on the halo mass at $\log(M_\mathrm{host}/M_\odot) < 11.84$. We find that the stellar-to-halo mass ratio of the LSBG samples is consistent with that of the general galaxy population. This work illustrates the viability of using weak gravitational lensing to constrain the halo masses of LSBGs., Comment: 20 pages, 14 figures
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- 2024
- Full Text
- View/download PDF
21. Reacting on human stubbornness in human-machine trajectory planning
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Schneider, Julian, Straky, Niels, Meyer, Simon, Varga, Balint, and Hohmann, Sören
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Computer Science - Robotics ,Electrical Engineering and Systems Science - Systems and Control - Abstract
In this paper, a method for a cooperative trajectory planning between a human and an automation is extended by a behavioral model of the human. This model can characterize the stubbornness of the human, which measures how strong the human adheres to his preferred trajectory. Accordingly, a static model is introduced indicating a link between the force in haptically coupled human-robot interactions and humans's stubbornness. The introduced stubbornness parameter enables an application-independent reaction of the automation for the cooperative trajectory planning. Simulation results in the context of human-machine cooperation in a care application show that the proposed behavioral model can quantitatively estimate the stubbornness of the interacting human, enabling a more targeted adaptation of the automation to the human behavior.
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- 2024
22. Subthalamic Nucleus segmentation in high-field Magnetic Resonance data. Is space normalization by template co-registration necessary?
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Lima, Tomás, Varga, Igor, Bakštein, Eduard, Novák, Daniel, and Alves, Victor
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Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Deep Brain Stimulation (DBS) is one of the most successful methods to diminish late-stage Parkinson's Disease (PD) symptoms. It is a delicate surgical procedure which requires detailed pre-surgical patient's study. High-field Magnetic Resonance Imaging (MRI) has proven its improved capacity of capturing the Subthalamic Nucleus (STN) - the main target of DBS in PD - in greater detail than lower field images. Here, we present a comparison between the performance of two different Deep Learning (DL) automatic segmentation architectures, one based in the registration to a brain template and the other performing the segmentation in in the MRI acquisition native space. The study was based on publicly available high-field 7 Tesla (T) brain MRI datasets of T1-weighted and T2-weighted sequences. nnUNet was used on the segmentation step of both architectures, while the data pre and post-processing pipelines diverged. The evaluation metrics showed that the performance of the segmentation directly in the native space yielded better results for the STN segmentation, despite not showing any advantage over the template-based method for the to other analysed structures: the Red Nucleus (RN) and the Substantia Nigra (SN).
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- 2024
23. Description of the hydrogen atom and the He+ ion in an optical cavity using the Pauli-Fierz Hamiltonian
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Aklilu, Yetmgeta and Varga, Kálmán
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Physics - Chemical Physics ,Quantum Physics - Abstract
A system of one electron in a Coulomb potential in an optical cavity is solved using a tensor-product light-matter basis. The problem was treated at the level of the Pauli-Fierz Hamiltonian describing both light and matter quantum mechanically. The effect of cavity size on the energy levels and high harmonics generation (HHG) spectrum is studied. We have shown that the energy levels, transition states, entanglement, and the HHG spectrum can be strongly influenced by changing the cavity size.
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- 2024
24. Dynamics of quantum turbulence in axially rotating thermal counterflow
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Dwivedi, Ritesh, Dunca, Tomáš, Novotný, Filip, Talíř, Marek, Skrbek, Ladislav, Urban, Pavel, Zobač, Martin, Vlček, Ivan, and Varga, Emil
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Physics - Fluid Dynamics ,Condensed Matter - Other Condensed Matter - Abstract
Generation, statistically steady state, and temporal decay of axially rotating thermal counterflow of superfluid $^4$He (He~II) in a square channel is probed using the second sound attenuation technique, measuring the density of quantized vortex lines. The array of rectilinear quantized vortices created by rotation strongly affects the development of quantum turbulence. At relatively slow angular velocities, the type of instability responsible for the destruction of the laminar counterflow qualitatively changes: the growth of seed vortex loops pinned on the channel wall becomes gradually replaced by the growth due to Donnelly-Glaberson instability, which leads to rapid growth of helical Kelvin waves on vortices parallel with applied counterflow. The initial transient growth of vortex line density that follows the sudden start of the counterflow appears self-similar, linear in dimensionless time, $\Omega t$. We show numerically that Kelvin waves of sufficiently strong amplitude reorient the vortices into more flattened shapes, which grow similarly to a free vortex ring. The observed steady state vortex line density at sufficiently high counterflow velocity and its early temporal decay after the counterflow is switched off is not appreciably affected by rotation. It is striking, however, that although the steady state of rotating counterflow is very different from rotating classical grid-generated turbulence, the late temporal decay of both displays similar features: the decay exponent decreases with the rotation rate $\Omega$ from -3/2 towards approximately -0.7, typical for two-dimensional turbulence, consistent with the transition to bidirectional cascade., Comment: 20 pages, 9 figures, 2 videos
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- 2024
25. Backward Behavior and Determining Functionals for Chevron Pattern Equations
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Kalantarov, Varga K., Kalantarova, Habiba V., and Vantzos, Orestis
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Mathematics - Analysis of PDEs - Abstract
The paper is devoted to the study of the backward behavior of solutions of the initial boundary value problem for the chevron pattern equations under homogeneous Dirichlet's boundary conditions. We prove that, as $t\rightarrow \infty$, the asymptotic behavior of solutions of the considered problem is completely determined by the dynamics of a finite set of functionals. Furthermore, we provide numerical evidence for the blow-up of certain solutions of the backward problem in finite time in 1D.
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- 2024
26. Diverse beam search to find densest-known planar unit distance graphs
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Engel, Peter, Hammond-Lee, Owen, Su, Yiheng, Varga, Dániel, and Zsámboki, Pál
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Mathematics - Combinatorics ,Computer Science - Discrete Mathematics ,Mathematics - Metric Geometry - Abstract
This paper addresses the problem of determining the maximum number of edges in a unit distance graph (UDG) of $n$ vertices using computer search. An unsolved problem of Paul Erd\H{o}s asks the maximum number of edges $u(n)$ a UDG of $n$ vertices can have. Those UDGs that attain $u(n)$ are called "maximally dense." In this paper, we seek to demonstrate a computer algorithm to generate dense UDGs for vertex counts up to at least 100. Via beam search with an added visitation metric, our algorithm finds all known maximally dense UDGs up to isomorphism at the push of a button. In addition, for $15 < n$, where $u(n)$ is unknown, i) the algorithm finds all previously published densest UDGs up to isomorphism for $15 < n \le 30$, and ii) the rate of growth of $u(n)/n$ remains similar for $30 < n$. The code and database of over 60 million UDGs found by our algorithm will be open-sourced at time of publication.
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- 2024
27. Critical behavior and multistability in quasi-two-dimensional turbulence
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Novotný, Filip, Talíř, Marek, Midlik, Šimon, and Varga, Emil
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Physics - Fluid Dynamics ,Condensed Matter - Other Condensed Matter - Abstract
Two-dimensional (2D) turbulence, despite being an idealization of real flows, is of fundamental interest as a model of the spontaneous emergence of order from chaotic flows. The emergence of order often displays critical behavior, whose study is hindered by the long spatial and temporal scales involved. Here, we experimentally study turbulence in periodically driven nanofluidic channels with a high aspect ratio using superfluid helium. We find a multistable transition behavior resulting from cascading bifurcations of large-scale vorticity and critical behavior at the transition to quasi-2D turbulence consistent with phase transitions in periodically driven many-body systems. We demonstrate that quasi-2D turbulent systems can undergo an abrupt change in response to a small change in a control parameter, consistent with predictions for large-scale atmospheric or oceanic flows., Comment: 24 pages (6 pages main text + 18 SI), 21 figures (4 + 17)
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- 2024
28. Theory of magnetotrion-polaritons in transition metal dichalcogenide monolayers
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Kudlis, A., Aleksandrov, I. A., Varga, K., Shelykh, I. A., and Shahnazaryan, V.
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Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Materials Science - Abstract
Magnetic field is a powerful tool for the manipulation of material's electronic and optical properties. In the domain of transition metal dichalcogenide monolayers, it allows one to unveil the spin, valley, and orbital properties of many-body excitonic complexes. Here we study theoretically the impact of normal-to-plane magnetic field on trions and trion-polaritons. We demonstrate that spin and orbital effects of a magnetic field give comparable contributions to the trion energies. Moreover, as magnetic field redistributes the free electron gas between two valleys in the conductance band, the trion-photon coupling becomes polarization and valley dependent. This results in an effective giant Zeeman splitting of trion-polaritons, in-line with the recent experimental observations.
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- 2024
29. GRAVITY for MATISSE -- Improving the MATISSE performance with the GRAVITY fringe tracker
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Woillez, J., Petrov, R., Abuter, R., Allouche, F., Berio, P., Dembet, R., Eisenhauer, F., Frahm, R., Gonté, F., Haubois, X., Houllé, M., Jaffe, W., Lacour, S., Lagarde, S., Leftley, J., Lopez, B., Matter, A., Meilland, A., Millour, F., Nowak, M., Paladini, C., Rivinius, T., Salabert, D., Schuhler, N., Varga, J., and Zins, G.
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Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
Context: MATISSE, the mid-infrared spectro-imaging instrument of VLTI, was designed to deliver its advertised performance when paired with an external second generation fringe tracker. Science observation started in 2019, demonstrating imaging capabilities and faint science target observations. Now, The GRAVITY fringe tracker stabilizes the MATISSE fringes which allows using all spectroscopic modes and improves sensitivity and data accuracy. Aims: We present how the MATISSE and GRAVITY instruments were adapted to make the GRAVITY fringe tracker work with MATISSE, under the umbrella of the aptly-named GRA4MAT project, led by ESO in collaboration with the two instrument consortia. Methods: We detail the software modifications needed to implement an acquisition and observing sequence specific to GRA4MAT, including simultaneous fringe tracking and chopping and a narrow off-axis capability inspired by the galactic center and exoplanet capability of GRAVITY. We explain the modified data collection and reduction processes. We show how we leveraged the recent fringe tracker upgrade to implement features specific to its use with MATISSE, e.g. fringe jumps mitigation with an improved group delay control and simultaneous fringe tracking and chopping with a new state machine. Results: We successfully demonstrate significant improvements to the MATISSE instrument. Observations can now be performed at higher spectral resolutions of up to $R\sim3300$ and across the full LM bands at once. Long detector integration times, made possible with stabilized fringes, have improved the LM-bands sensitivity by a factor of 10. Low flux biases in coherently-reduced N-band data have been eliminated. The L-band transfer function is now higher and more stable. We finally illustrate the scientific potential of GRA4MAT with a preview of the first exoplanet observation made by MATISSE on $\beta$ Pictoris b., Comment: Revised after language editing
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- 2024
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- View/download PDF
30. Dark Energy Survey Year 3 results: simulation-based cosmological inference with wavelet harmonics, scattering transforms, and moments of weak lensing mass maps II. Cosmological results
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Gatti, M., Campailla, G., Jeffrey, N., Whiteway, L., Porredon, A., Prat, J., Williamson, J., Raveri, M., Jain, B., Ajani, V., Giannini, G., Yamamoto, M., Zhou, C., Blazek, J., Anbajagane, D., Samuroff, S., Kacprzak, T., Alarcon, A., Amon, A., Bechtol, K., Becker, M., Bernstein, G., Campos, A., Chang, C., Chen, R., Choi, A., Davis, C., Derose, J., Diehl, H. T., Dodelson, S., Doux, C., Eckert, K., Elvin-Poole, J., Everett, S., Ferte, A., Gruen, D., Gruendl, R., Harrison, I., Hartley, W. G., Herner, K., Huff, E. M., Jarvis, M., Kuropatkin, N., Leget, P. F., MacCrann, N., McCullough, J., Myles, J., Navarro-Alsina, A., Pandey, S., Rollins, R. P., Roodman, A., Sanchez, C., Secco, L. F., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Troxel, M., Tutusaus, I., Varga, T. N., Yanny, B., Yin, B., Zhang, Y., Zuntz, J., Abbott, T. M. C., Aguena, M., Allam, S. S., Alves, O., Andrade-Oliveira, F., Bacon, D., Bocquet, S., Brooks, D., Rosell, A. Carnero, Carretero, J., da Costa, L. N., Pereira, M. E. S., De Vicente, J., Ferrero, I., Frieman, J., García-Bellido, J., Gaztanaga, E., Gutierrez, G., Hinton, S. R., Hollowood, D. L., Honscheid, K., James, D. J., Kuehn, K., Lahav, O., Lee, S., Marshall, J. L., Mena-Fernández, J., Miquel, R., Pieres, A., Malagón, A. A. Plazas, Sanchez, E., Cid, D. Sanchez, Schubnell, M., Smith, M., Suchyta, E., Tarle, G., Weaverdyck, N., Weller, J., and Wiseman, P.
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Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a simulation-based cosmological analysis using a combination of Gaussian and non-Gaussian statistics of the weak lensing mass (convergence) maps from the first three years (Y3) of the Dark Energy Survey (DES). We implement: 1) second and third moments; 2) wavelet phase harmonics; 3) the scattering transform. Our analysis is fully based on simulations, spans a space of seven $\nu w$CDM cosmological parameters, and forward models the most relevant sources of systematics inherent in the data: masks, noise variations, clustering of the sources, intrinsic alignments, and shear and redshift calibration. We implement a neural network compression of the summary statistics, and we estimate the parameter posteriors using a simulation-based inference approach. Including and combining different non-Gaussian statistics is a powerful tool that strongly improves constraints over Gaussian statistics (in our case, the second moments); in particular, the Figure of Merit $\textrm{FoM}(S_8, \Omega_{\textrm{m}})$ is improved by 70 percent ($\Lambda$CDM) and 90 percent ($w$CDM). When all the summary statistics are combined, we achieve a 2 percent constraint on the amplitude of fluctuations parameter $S_8 \equiv \sigma_8 (\Omega_{\textrm{m}}/0.3)^{0.5}$, obtaining $S_8 = 0.794 \pm 0.017$ ($\Lambda$CDM) and $S_8 = 0.817 \pm 0.021$ ($w$CDM). The constraints from different statistics are shown to be internally consistent (with a $p$-value>0.1 for all combinations of statistics examined). We compare our results to other weak lensing results from the DES Y3 data, finding good consistency; we also compare with results from external datasets, such as \planck{} constraints from the Cosmic Microwave Background, finding statistical agreement, with discrepancies no greater than $<2.2\sigma$., Comment: 24 pages, 13 figures, to be submitted to PRD. Comments welcome!
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- 2024
31. Quantum-inspired clustering with light
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Varga, Miguel, Bermejo, Pablo, Pellicer-Guridi, Rubén, Orús, Román, and Molina-Terriza, Gabriel
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Quantum Physics ,Physics - Optics - Abstract
This article introduces a novel approach to perform the simulation of a single qubit quantum algorithm using laser beams. Leveraging the polarization states of photonic qubits, and inspired by variational quantum eigensolvers, we develop a variational quantum algorithm implementing a clustering procedure following the approach proposed by some of us in SciRep 13, 13284 (2023). A key aspect of our research involves the utilization of non-orthogonal states within the photonic domain, harnessing the potential of polarization schemes to reproduce unitary circuits. By mapping these non-orthogonal states into polarization states, we achieve an efficient and versatile quantum information processing unit which serves as a clustering device for a diverse set of datasets., Comment: 5 pages, 5 figures
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- 2024
32. Human-Variability-Respecting Optimal Control for Physical Human-Machine Interaction
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Kille, Sean, Leibold, Paul, Karg, Philipp, Varga, Balint, and Hohmann, Sören
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Electrical Engineering and Systems Science - Systems and Control - Abstract
Physical Human-Machine Interaction plays a pivotal role in facilitating collaboration across various domains. When designing appropriate model-based controllers to assist a human in the interaction, the accuracy of the human model is crucial for the resulting overall behavior of the coupled system. When looking at state-of-the-art control approaches, most methods rely on a deterministic model or no model at all of the human behavior. This poses a gap to the current neuroscientific standard regarding human movement modeling, which uses stochastic optimal control models that include signal-dependent noise processes and therefore describe the human behavior much more accurate than the deterministic counterparts. To close this gap by including these stochastic human models in the control design, we introduce a novel design methodology resulting in a Human-Variability-Respecting Optimal Control that explicitly incorporates the human noise processes and their influence on the mean and variability behavior of a physically coupled human-machine system. Our approach results in an improved overall system performance, i.e. higher accuracy and lower variability in target point reaching, while allowing to shape the joint variability, for example to preserve human natural variability patterns.
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- 2024
33. Novel method for in-situ drift velocity measurement in large volume TPCs: the Geometry Reference Chamber of the NA61/SHINE experiment at CERN
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Laszlo, Andras, Gera, Adam, Hamar, Gergo, Palfi, Botond, Podlaski, Piotr, Rumberger, Brant, and Varga, Dezso
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Physics - Instrumentation and Detectors ,High Energy Physics - Experiment ,Nuclear Experiment - Abstract
This paper presents a novel method for low maintenance, low ambiguity in-situ drift velocity monitoring in large volume Time Projection Chambers (TPCs). The method was developed and deployed for the 40m^3 TPC tracker system of the NA61/SHINE experiment at CERN, which has a one meter of drift length. The method relies on a low-cost multi-wire proportional chamber placed next to the TPC to be monitored, downstream with respect to the particle flux. Reconstructed tracks in the TPC are matched to hits in the monitoring chamber, called the Geometry Reference Chamber (GRC). Relative differences in positions of hits in the GRC are used to estimate the drift velocity, removing the need for an accurate alignment of the TPC to the GRC. An important design requirement on the GRC was minimal added complexity to the existing system, in particular, compatibility with Front-End Electronics cards already used to read out the TPCs. Moreover, the GRC system was designed to operate both in large and small particle fluxes. The system is capable of monitoring the evolution of the drift velocity inside the TPC down to a one permil precision, with a few minutes of data collection., Comment: 18 pages, 9 figures
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- 2024
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34. Bertrand oligopoly in insurance markets with Value at Risk Constraints
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Ágoston, Kolos Csaba and Varga, Veronika
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Economics - Theoretical Economics ,Quantitative Finance - Risk Management - Abstract
Since 2016 the operation of insurance companies in the European Union is regulated by the Solvency II directive. According to the EU directive the capital requirement should be calculated as a 99.5\% of Value at Risk. In this study, we examine the impact of this capital requirement constraint on equilibrium premiums and capitals. We discuss the case of the oligopoly insurance market using Bertrand's model, assuming profit maximizing insurance companies facing Value at Risk constraints. First we analyze companies' decision on premium level. The companies strategic behavior can result positive as well as negative expected profit for companies. The desired situation where competition eliminate positive profit and lead the market to zero-profit state is rare. Later we examine ex post and ax ante capital adjustments. Capital adjustment does not rule out market anomalies, although somehow changes them. Possibility of capital adjustment can lead the market to a situation where all of the companies suffer loss. Allowing capital adjustment results monopolistic premium level or market failure with positive probabilities., Comment: 47 pages
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- 2024
35. On the incidence rate of RR Lyrae stars with non-radial modes
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Netzel, H., Varga, V., Szabo, R., Smolec, R., and Plachy, E.
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Astrophysics - Solar and Stellar Astrophysics - Abstract
Over the recent years, additional low-amplitude non-radial modes were detected in many of the first-overtone RR Lyrae stars. These non-radial modes form a characteristic period ratio with the dominant first-overtone mode of around 0.61. The incidence rate of this phenomenon changes from population to population. It is also strongly dependent on the quality of the analyzed data. Current models explaining these additional signals involve non-radial modes of degrees 8 and 9. Using synthetic horizontal branch populations, we investigate the incidence rate of first-overtone RR Lyrae stars with non-radial modes depending on the population properties, i.e., ages and metallicities. We compare our results with the observed results for globular clusters and the numerous collection of field first-overtone RR Lyrae stars to test the predictions of the models. We used synthetic horizontal branches combined with pulsation models to predict how the incidence rate would depend on the age and metallicity of the population. To test whether the results based on synthetic horizontal branches are realistic, we compared them to incidence rates observed by TESS in first-overtone field RR Lyrae stars, using photometric metallicity values from a newly established calibration for TESS. The analysis of synthetic horizontal branches showed that the incidence rate decreases with decreasing metallicity. We inferred photometric metallicity for RR Lyrae stars observed by TESS and showed that the theoretical predictions are in agreement with the observations. Using the same method, we also conclude that the metallicity distribution of RR Lyrae stars showing an additional mode with a period-ratio around $0.68$ appears to be different from that of both all first-overtone stars and those showing additional non-radial modes., Comment: 9 pages, 7 figures, 2 tables, accepted for publication in A&A
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- 2024
36. X-ray Interferometry Using a Modulated Phase Grating: Theory and Experiments
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Meyer, Hunter, Dey, Joyoni, Carr, Sydney, Ham, Kyungmin, Butler, Leslie G., Dooley, Kerry M., Hidrovo, Ivan, Bleuel, Markus, Varga, Tamas, Schulz, Joachim, Beckenbach, Thomas, and Kaiser, Konradin
- Subjects
Physics - Optics ,Physics - Instrumentation and Detectors ,Physics - Medical Physics - Abstract
X-ray grating interferometry allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, resulting from X-ray attenuation, refraction, and small-angle scattering, respectively. The modulated phase grating (MPG) interferometer is a recently developed grating interferometry system capable of generating a directly resolvable interference pattern using a relatively large period grating envelope function that is sampled at a pitch that allows for X-ray spatial coherence using a microfocus X-ray source or by use of a source G0 grating that follows the Lau condition. We present the theory of the MPG interferometry system for a 2-dimensional staggered grating, derived using Fourier optics, and we compare the theoretical predictions with experiments we have performed with a microfocus X-ray system at Pennington Biomedical Research Center, LSU. The theoretical and experimental fringe visibility is evaluated as a function of grating-to-detector distance. Quantitative experiments are performed with porous carbon and alumina samples, and qualitative analysis of attenuation and dark-field images of a dried anchovy are shown., Comment: 22 pages, 13 figures. This is a pre-print
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- 2024
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- View/download PDF
37. Non-stationary Financial Risk Factors and Macroeconomic Vulnerability for the UK
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Varga, Katalin and Szendrei, Tibor
- Subjects
Quantitative Finance - Statistical Finance - Abstract
Tracking the build-up of financial vulnerabilities is a key component of financial stability policy. Due to the complexity of the financial system, this task is daunting, and there have been several proposals on how to manage this goal. One way to do this is by the creation of indices that act as a signal for the policy maker. While factor modelling in finance and economics has a rich history, most of the applications tend to focus on stationary factors. Nevertheless, financial stress (and in particular tail events) can exhibit a high degree of inertia. This paper advocates moving away from the stationary paradigm and instead proposes non-stationary factor models as measures of financial stress. Key advantage of a non-stationary factor model is that while some popular measures of financial stress describe the variance-covariance structure of the financial stress indicators, the new index can capture the tails of the distribution. To showcase this, we use the obtained factors as variables in a growth-at-risk exercise. This paper offers an overview of how to construct non-stationary dynamic factors of financial stress using the UK financial market as an example.
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- 2024
38. UAV-Assisted Maritime Search and Rescue: A Holistic Approach
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Messmer, Martin, Kiefer, Benjamin, Varga, Leon Amadeus, and Zell, Andreas
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Computer Science - Robotics - Abstract
In this paper, we explore the application of Unmanned Aerial Vehicles (UAVs) in maritime search and rescue (mSAR) missions, focusing on medium-sized fixed-wing drones and quadcopters. We address the challenges and limitations inherent in operating some of the different classes of UAVs, particularly in search operations. Our research includes the development of a comprehensive software framework designed to enhance the efficiency and efficacy of SAR operations. This framework combines preliminary detection onboard UAVs with advanced object detection at ground stations, aiming to reduce visual strain and improve decision-making for operators. It will be made publicly available upon publication. We conduct experiments to evaluate various Region of Interest (RoI) proposal methods, especially by imposing simulated limited bandwidth on them, an important consideration when flying remote or offshore operations. This forces the algorithm to prioritize some predictions over others.
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- 2024
39. Toward Adaptive Cooperation: Model-Based Shared Control Using LQ-Differential Games
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Varga, Balint
- Subjects
Electrical Engineering and Systems Science - Systems and Control ,Computer Science - Robotics - Abstract
This paper introduces a novel model-based adaptive shared control to allow for the identification and design challenge for shared-control systems, in which humans and automation share control tasks. The main challenge is the adaptive behavior of the human in such shared control interactions. Consequently, merely identifying human behavior without considering automation is insufficient and often leads to inadequate automation design. Therefore, this paper proposes a novel solution involving online identification of the human and the adaptation of shared control using Linear-Quadratic differential games. The effectiveness of the proposed online adaptation is analyzed in simulations and compared with a non-adaptive shared control from the state of the art. Finally, the proposed approach is tested through human-in-the-loop experiments, highlighting its suitability for real-time applications.
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- 2024
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- View/download PDF
40. Characterisation of analogue Monolithic Active Pixel Sensor test structures implemented in a 65 nm CMOS imaging process
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Rinella, Gianluca Aglieri, Alocco, Giacomo, Antonelli, Matias, Baccomi, Roberto, Beole, Stefania Maria, Blidaru, Mihail Bogdan, Buttwill, Bent Benedikt, Buschmann, Eric, Camerini, Paolo, Carnesecchi, Francesca, Chartier, Marielle, Choi, Yongjun, Colocci, Manuel, Contin, Giacomo, Dannheim, Dominik, De Gruttola, Daniele, Viera, Manuel Del Rio, Dubla, Andrea, di Mauro, Antonello, Donner, Maurice Calvin, Eberwein, Gregor Hieronymus, Egger, Jan, Fabbietti, Laura, Feindt, Finn, Gautam, Kunal, Gernhaeuser, Roman, Glover, James Julian, Gonella, Laura, Grodaas, Karl Gran, Gregor, Ingrid-Maria, Hillemanns, Hartmut, Huth, Lennart, Ilg, Armin, Isakov, Artem, Jones, Daniel Matthew, Junique, Antoine, Kaewjai, Jetnipit, Keil, Markus, Kim, Jiyoung, Kluge, Alex, Kobdaj, Chinorat, Kotliarov, Artem, Kittimanapun, Kritsada, Křížek, Filip, Kucharska, Gabriela, Kushpil, Svetlana, La Rocca, Paola, Laojamnongwong, Natthawut, Lautner, Lukas, Lemmon, Roy Crawford, Lemoine, Corentin, Li, Long, Librizzi, Francesco, Liu, Jian, Macchiolo, Anna, Mager, Magnus, Marras, Davide, Martinengo, Paolo, Masciocchi, Silvia, Mattiazzo, Serena, Menzel, Marius Wilm, Mulliri, Alice, Mylne, Mia Rose, Piro, Francesco, Rachevski, Alexandre, Rasà, Marika, Rebane, Karoliina, Reidt, Felix, Ricci, Riccardo, Daza, Sara Ruiz, Saccà, Gaspare, Sanna, Isabella, Sarritzu, Valerio, Schlaadt, Judith, Schledewitz, David, Scioli, Gilda, Senyukov, Serhiy, Simancas, Adriana, Snoeys, Walter, Spannagel, Simon, Šuljić, Miljenko, Sturniolo, Alessandro, Tiltmann, Nicolas, Trifirò, Antonio, Usai, Gianluca, Vanat, Tomas, Van Beelen, Jacob Bastiaan, Varga, Laszlo, Verdoglia, Michele, Vignola, Gianpiero, Villani, Anna, Wennloef, Haakan, Witte, Jonathan, and Wittwer, Rebekka Bettina
- Subjects
Physics - Instrumentation and Detectors - Abstract
Analogue test structures were fabricated using the Tower Partners Semiconductor Co. CMOS 65 nm ISC process. The purpose was to characterise and qualify this process and to optimise the sensor for the next generation of Monolithic Active Pixels Sensors for high-energy physics. The technology was explored in several variants which differed by: doping levels, pixel geometries and pixel pitches (10-25 $\mu$m). These variants have been tested following exposure to varying levels of irradiation up to 3 MGy and $10^{16}$ 1 MeV n$_\text{eq}$ cm$^{-2}$. Here the results from prototypes that feature direct analogue output of a 4$\times$4 pixel matrix are reported, allowing the systematic and detailed study of charge collection properties. Measurements were taken both using $^{55}$Fe X-ray sources and in beam tests using minimum ionizing particles. The results not only demonstrate the feasibility of using this technology for particle detection but also serve as a reference for future applications and optimisations.
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- 2024
41. Piquasso: A Photonic Quantum Computer Simulation Software Platform
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Kolarovszki, Zoltán, Rybotycki, Tomasz, Rakyta, Péter, Kaposi, Ágoston, Poór, Boldizsár, Jóczik, Szabolcs, Nagy, Dániel T. R., Varga, Henrik, El-Safty, Kareem H., Morse, Gregory, Oszmaniec, Michał, Kozsik, Tamás, and Zimborás, Zoltán
- Subjects
Quantum Physics - Abstract
We introduce the Piquasso quantum programming framework, a full-stack open-source software platform for the simulation and programming of photonic quantum computers. Piquasso can be programmed via a high-level Python programming interface enabling users to perform efficient quantum computing with discrete and continuous variables. Via optional high-performance C++ backends, Piquasso provides state-of-the-art performance in the simulation of photonic quantum computers. The Piquasso framework is supported by an intuitive web-based graphical user interface where the users can design quantum circuits, run computations, and visualize the results., Comment: The source code is made available at https://github.com/Budapest-Quantum-Computing-Group/piquasso, and the documentation is published at https://piquasso.readthedocs.io/; November 2024 update: code examples adapted to Piquasso v5.0.0, presentation improved, minor errors corrected, references updated, new "Benchmarks" section added
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- 2024
42. Dark Energy Survey Year 3 results: likelihood-free, simulation-based $w$CDM inference with neural compression of weak-lensing map statistics
- Author
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Jeffrey, N., Whiteway, L., Gatti, M., Williamson, J., Alsing, J., Porredon, A., Prat, J., Doux, C., Jain, B., Chang, C., Cheng, T. -Y., Kacprzak, T., Lemos, P., Alarcon, A., Amon, A., Bechtol, K., Becker, M. R., Bernstein, G. M., Campos, A., Rosell, A. Carnero, Chen, R., Choi, A., DeRose, J., Drlica-Wagner, A., Eckert, K., Everett, S., Ferté, A., Gruen, D., Gruendl, R. A., Herner, K., Jarvis, M., McCullough, J., Myles, J., Navarro-Alsina, A., Pandey, S., Raveri, M., Rollins, R. P., Rykoff, E. S., Sánchez, C., Secco, L. F., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Troxel, M. A., Tutusaus, I., Varga, T. N., Yanny, B., Yin, B., Zuntz, J., Aguena, M., Allam, S. S., Alves, O., Bacon, D., Bocquet, S., Brooks, D., da Costa, L. N., Davis, T. M., De Vicente, J., Desai, S., Diehl, H. T., Ferrero, I., Frieman, J., García-Bellido, J., Gaztanaga, E., Giannini, G., Gutierrez, G., Hinton, S. R., Hollowood, D. L., Honscheid, K., Huterer, D., James, D. J., Lahav, O., Lee, S., Marshall, J. L., Mena-Fernández, J., Miquel, R., Pieres, A., Malagón, A. A. Plazas, Roodman, A., Sako, M., Sanchez, E., Cid, D. Sanchez, Smith, M., Suchyta, E., Swanson, M. E. C., Tarle, G., Tucker, D. L., Weaverdyck, N., Weller, J., Wiseman, P., and Yamamoto, M.
- Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present simulation-based cosmological $w$CDM inference using Dark Energy Survey Year 3 weak-lensing maps, via neural data compression of weak-lensing map summary statistics: power spectra, peak counts, and direct map-level compression/inference with convolutional neural networks (CNN). Using simulation-based inference, also known as likelihood-free or implicit inference, we use forward-modelled mock data to estimate posterior probability distributions of unknown parameters. This approach allows all statistical assumptions and uncertainties to be propagated through the forward-modelled mock data; these include sky masks, non-Gaussian shape noise, shape measurement bias, source galaxy clustering, photometric redshift uncertainty, intrinsic galaxy alignments, non-Gaussian density fields, neutrinos, and non-linear summary statistics. We include a series of tests to validate our inference results. This paper also describes the Gower Street simulation suite: 791 full-sky PKDGRAV dark matter simulations, with cosmological model parameters sampled with a mixed active-learning strategy, from which we construct over 3000 mock DES lensing data sets. For $w$CDM inference, for which we allow $-1
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- 2024
43. Effects of sex and obesity on immune checkpoint inhibition-related cardiac systolic dysfunction in aged mice
- Author
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Sayour, Nabil V., Kucsera, Dániel, Alhaddad, Ayham R., Tóth, Viktória É., Gergely, Tamás G., Kovács, Tamás, Hegedűs, Zsombor I., Jakab, Márk E., Ferdinandy, Péter, and Varga, Zoltán V.
- Published
- 2024
- Full Text
- View/download PDF
44. Community-based propagation to scale up educational innovations in sustainability
- Author
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Rooney-Varga, Juliette N., Kapmeier, Florian, Henderson, Charles, and Ford, David N.
- Published
- 2024
- Full Text
- View/download PDF
45. Square values of Littlewood polynomials
- Author
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Hajdu, L., Herendi, O., Tengely, Sz., and Varga, N.
- Published
- 2024
- Full Text
- View/download PDF
46. Understanding perioperative risk determinants in carotid endarterectomy: the impact of compromised circle of Willis morphology on inter-hemispheric blood flow indices based on intraoperative internal carotid artery stump pulse pressure and backflow patterns
- Author
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Czinege, Zsófia, Sándor, Ágnes Dóra, Gyürki, Dániel, Varga, Andrea, Csípő, Tamás, Székely, Andrea, Ungvári, Zoltán, Banga, Péter, Sótonyi, Péter, and Horváth, Tamás
- Published
- 2024
- Full Text
- View/download PDF
47. Deep learning super-resolution reconstruction for fast and high-quality cine cardiovascular magnetic resonance
- Author
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Kravchenko, Dmitrij, Isaak, Alexander, Mesropyan, Narine, Peeters, Johannes M., Kuetting, Daniel, Pieper, Claus C., Katemann, Christoph, Attenberger, Ulrike, Emrich, Tilman, Varga-Szemes, Akos, and Luetkens, Julian A.
- Published
- 2024
- Full Text
- View/download PDF
48. Updated uranium reference material 231Pa/235U consensus model ages for nuclear forensics
- Author
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Edwards, Mark A., Varga, Zsolt, Gaffney, Amy M., Denton, Joanna S., Engel, John R., Gonzales, Matthew S., Kayzar-Boggs, Theresa M., Mayer, Klaus, Nicholl, Adrian, Sanborn, Matthew E., Steiner, Robert E., Tarng, Cheng, Treinen, Kerri C., Wallenius, Maria, and Wende, Allison M.
- Published
- 2024
- Full Text
- View/download PDF
49. Photonenzählende Detektor-Computertomographie: Paradigmenwechsel in der kardialen CT-Bildgebung
- Author
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Kravchenko, Dmitrij, Layer, Yannik Christian, Vecsey-Nagy, Milan, Tremamunno, Giuseppe, Varga-Szemes, Akos, Schlett, Christopher L., Bamberg, Fabian, Emrich, Tilman, and Hagar, Muhammad Taha
- Published
- 2024
- Full Text
- View/download PDF
50. Overweight and obesity significantly increase colorectal cancer risk: a meta-analysis of 66 studies revealing a 25–57% elevation in risk
- Author
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Ungvari, Zoltan, Fekete, Mónika, Varga, Peter, Lehoczki, Andrea, Fekete, János Tibor, Ungvari, Anna, and Győrffy, Balázs
- Published
- 2024
- Full Text
- View/download PDF
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