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In this work, we study metric-Palatini gravity extended by the antisymmetric part of the affine curvature. This gravity theory leads to general relativity plus a geometric Proca field. Using our previous construction of its static spherically-symmetric AdS solution (Eur Phys J. C 83(4):318, 2023), we perform a detailed analysis in this work using the observational quasiperiodic oscillations (QPOs) data. To this end, we use the latest data from stellar-mass black hole GRO J1655-40, intermediate-mass black hole in M82-X1, and the super-massive black hole in SgA* (our Milky Way) and perform a Monte-Carlo-Markov-Chain (MCMC) analysis to determine or bound the model parameters. Our results shed light on the allowed ranges of the Proca mass and other parameters. The results imply that our solutions can cover all three astrophysical black holes. Our analysis can also be extended to more general metric-affine gravity theories. [ABSTRACT FROM AUTHOR]

The geometric trinity of gravity comprises three distinct formulations of general relativity: (i) the standard formulation describing gravity in terms of spacetime curvature, (ii) the teleparallel equivalent of general relativity describing gravity in terms of spacetime torsion, and (iii) the symmetric teleparallel equivalent of general relativity (STEGR) describing gravity in terms of spacetime non-metricity. In this article, we complete a geometric trinity of non-relativistic gravity, by (a) taking the non-relativistic limit of STEGR to determine its non-relativistic analogue, and (b) demonstrating that this non-metric theory is equivalent to Newton–Cartan theory and its teleparallel equivalent, i.e., the curvature and the torsion based non-relativistic theories that are both geometrised versions of classical Newtonian gravity. [ABSTRACT FROM AUTHOR]

We analyze the orbits of a unit mass body in a background Reissner–Nordstr o ¨ m (RN) black hole in d = (3 + 1) from the perspectives of Geometric Torsion (GT) modified gravity theory in (4 + 1) dimensional bulk. A 4-form flux in bulk GT theory in d = (4 + 1) has been shown to ensure a mass dipole correction to the (3 + 1) dimensional gravity theory by Gupta, Kar and Rang recently. We argue that the dipole correction contributes topologically to the known exact geometries in General Theory of Relativity (GTR). Furthermore, the topological correction has been identified with non-Newtonian potential underlying a B 2 ∧ F 2 coupling term to Einstein–Hilbert action. The winding numbers ensured by the BF coupling to d = (3 + 1) action in the framework presumably provide a clue towards a tunneling instanton in theory. [ABSTRACT FROM AUTHOR]

In a work by Visser, Bassett and Liberati (VBL) (Nucl Phys B Proc Suppl 88:267, 2000) a relation was suggested between a null energy condition and the censorship of superluminal behaviour. Their result was soon challenged by Gao and Wald (Class Quantum Grav 17:4999, 2000) who argued that this relation is gauge dependent and therefore not appropriate to find such connections. In this paper, we clear up this controversy by showing that both papers are correct but need to be interpreted in distinct paradigms. In this context, we introduce a new paradigm to interpret gravitational phenomena, which we call the Harmonic Background Paradigm. This harmonic background paradigm starts from the idea that there exists a more fundamental background causality provided by a flat spacetime geometry. One of the consequences of this paradigm is that the VBL relation can provide an explanation of why gravity is attractive in all standard weak-field situations. [ABSTRACT FROM AUTHOR]

We present a comparative analysis of the plethora of nonextensive and/or nonadditive entropies which go beyond the standard Boltzmann–Gibbs formulation. After defining the basic notions of additivity, extensivity, and composability, we discuss the properties of these entropies and their mutual relations, if they exist. The results are presented in two informative tables that are of strong interest to the gravity and cosmology community in the context of the recently intensively explored horizon entropies for black hole and cosmological models. Gravitational systems admit long-range interactions, which usually lead to a break of the standard additivity rule for thermodynamic systems composed of subsystems in Boltzmann–Gibbs thermodynamics. The features of additivity, extensivity, and composability are listed systematically. A brief discussion on the validity of the notion of equilibrium temperature for nonextensive systems is also presented. [ABSTRACT FROM AUTHOR]

Recent advances in cold atom interferometry have cleared the path for space applications of quantum inertial sensors, whose level of stability is expected to increase dramatically with the longer interrogation times accessible in space. In this study, an in-orbit model is developed for a Mach–Zehnder-type cold-atom accelerometer. Performance tests are realized under different assumptions about the positioning and rotation compensation method, and the impact of various sources of errors on instrument stability is evaluated. Current and future advances for space-based atom interferometry are discussed, and their impact on the performance of quantum sensors on-board satellite gravity missions is investigated in three different scenarios: state-of-the-art scenario (expected to be ready to launch in 5 years), near-future (expected to be launched in the next 10 to 15 years) and far-future scenarios (expected for the next 20 to 25 years). Our results indicate that the highest sensitivity is achievable by positioning the electrostatic accelerometer at the center of mass of the satellite and the quantum accelerometer aside, on the cross-track axis of the satellite. We show that one can achieve a sensitivity level close to 5 × 10−10 m/s2/ Hz with the current state-of-the-art technology. We also estimate that in the near and far-future, atom interferometry in space is expected to achieve sensitivity levels of 1 × 10−11 m/s2/ Hz and 1 × 10−12 m/s2/ Hz , respectively. A roadmap for improvements in atom interferometry is provided that would maximize the performance of future quantum accelerometers, considering their technical capabilities. Finally, the possibility and challenges of having ultra-sensitive atom interferometry in space for future space missions are discussed. [ABSTRACT FROM AUTHOR]

Two vestibular signals, rotational and inertial cues, converge for the perception of complex motion. However, how vestibular perception is built on neuronal behaviors and decision-making processes, especially during the simultaneous presentation of rotational and inertial cues, has yet to be elucidated in humans. In this study, we analyzed the perceptual responses of 20 participants after pairwise rotational experiments, comprised of four control and four test sessions. In both control and test sessions, participants underwent clockwise and counterclockwise rotations in head-down and head-up positions. The difference between the control and test sessions was the head re-orientation relative to gravity after rotations, thereby providing only rotational cues in the control sessions and both rotational and inertial cues in the test sessions. The accuracy of perceptual responses was calculated by comparing the direction of rotational and inertial cues acquired from participants with that predicted by the velocity-storage model. The results showed that the accuracy of rotational perception ranged from 80 to 95% in the four control sessions but significantly decreased to 35 to 75% in the four test sessions. The accuracy of inertial perception in the test sessions ranged from 50 to 70%. The accuracy of rotational perception improved with repetitive exposure to the simultaneous presentation of both rotational and inertial cues, while the accuracy of inertial perception remained steady. The results suggested a significant interaction between rotational and inertial perception and implied that vestibular perception acquired in patients with vestibular disorders are potentially inaccurate. [ABSTRACT FROM AUTHOR]

Downbeat nystagmus (DBN) is the most common form of acquired central vestibular nystagmus. Gravity perception in patients with DBN has previously been investigated by means of subjective visual straight ahead (SVA) and subjective visual vertical (SVV) in the pitch and roll planes only during whole-body tilts. To our knowledge, the effect of head tilt in the roll plane on the SVV and on DBN has not yet been systematically studied in patients. In this study, we investigated static and dynamic graviceptive function in the roll-plane in patients with DBN (patients) and healthy-controls (controls) by assessment of the Subjective Visual Vertical (SVV) and the modulation of slow-phase-velocity (SPV) of DBN. SPV of DBN and SVV were tested at different head-on trunk-tilt positions in the roll-plane (0°,30° clockwise (cw) and 30° counterclockwise (ccw)) in 26 patients suffering from DBN and 13 controls. In patients, SPV of DBN did not show significant modulations at different head-tilt angles in the roll-plane. SVV ratings did not differ significantly between DBN patients vs. controls, however patients with DBN exhibited a higher variability in mean SVV estimates than controls. Our results show that the DBN does not exhibit any modulation in the roll-plane, in contrast to the pitch-plane. Furthermore, patients with DBN show a higher uncertainty in the perception of verticality in the roll-plane in form of a higher variability of responses. [ABSTRACT FROM AUTHOR]

Satellite altimetry data, with its increasing density and quality, has become the primary source for marine deflection of the vertical (DOV) and gravity anomaly modelling. Limited by orbital inclinations, the precision of the meridian component of the gridded deflection of the vertical (GDOV) calculated by traditional altimetry satellites is significantly better than that of the prime vertical component, and the excessive precision difference between these two components restricts the inversion precision of marine gravity anomaly model. The study of cross-track deflection of the vertical (CTDOV) is enabled by the multibeam synchronous observation mode of the new laser altimetry satellite, Ice, Cloud and Land Elevation Satellite-2 (ICESat-2). Based on the remove-restore method, residual geoid gradients are first calculated in this paper using three approaches: along-track (A-T), cross-track (C-T) and an integration of along-track and cross-track. Vertical deflections are then computed on a 1′ × 1′ grid using the least squares collocation (LSC) method, and the precision is verified against the SIO V32.1_DOV model. An optimized combination is proposed to address the issue of precision differences between the meridian and prime vertical components, and to enhance the precision of DOV inversion. A new DOV combination is formed by combining the meridian component from along-track deflection of the vertical (ATDOV) with the prime vertical component from cross-track deflection of the vertical (CTDOV) based on the remove-restore method. The Philippine Sea (0°–35°N, 120°–150°E) is selected as the test area to verify the feasibility of the optimized combination. The results indicate that the optimized combination of the meridian and prime vertical components achieved test precision of 2.63 and 3.33 μrad, respectively, when compared against the SIO V32.1_DOV model. The precision gap between the components is effectively narrowed by this approach, which maintains the precision of the meridian component and enhances that of the prime vertical component, thereby achieving optimal inversion precision for gravity anomalies. [ABSTRACT FROM AUTHOR]

Time-varying gravity fields play a crucial role in understanding and analysing geodynamic processes, particularly the migration of matter across the Earth's surface. However, the current limitations in spatiotemporal resolution hinder their accurate representation. In this context, the use of a giant constellation of low-orbit satellites holds great potential for accurately recovering time-varying gravity fields with high spatiotemporal resolution. Based on the orbital parameters of 5199 satellites in 123 different orbital planes in the first phase configuration of the Starlink constellation and the orbital parameters of the Bender constellation in the next generation gravity mission, we conducted a closed-loop simulation to analyse the recovery ability of time-varying gravity field in 9 d using the short-arc integral method. The errors of aliasing AOHIS signal (Atmosphere, Ocean, Hydrology, Ice and Solid Earth), ocean tide models, orbit positions, intersatellite range rates and accelerometer observations were considered in the numerical simulation. Compared with the Bender constellation, the Starlink-like constellation can effectively decrease the aliasing errors in the spatial- and frequency domain when the observation noise is not considered. The Starlink-like constellation can also effectively improve the reliability of low-degree coefficients (below degree 15) of retrieved time-varying gravity field models and present higher time resolution (within 9 d) for the full-degree spherical harmonic solutions than the Bender constellation when the observation noise is considered. The aliasing effect on the low-degree part of the Bender constellation can be significantly decreased by combining the Starlink-like and Bender constellations, and the accuracy of the recovered time-varying gravity field within degree 30 can be improved by about 0.5–1 order of magnitude. Our results can provide a technical reference for the design of future gravity satellite mission. [ABSTRACT FROM AUTHOR]

Inter-satellite interferometric missions are critical in the ongoing monitoring of climate change. Next-generation Earth geodesy missions are opportunities to improve on mission cost and measurement sensitivity through revised design. To be considered feasible, mission architectures must meet an optical power requirement that factors in both shot noise and laser frequency noise. Reference-transponder mission configurations, like the Gravity Recovery and Climate Experiment-Follow On (GRACE-FO) mission, are designed for measurement down to a received carrier-to-noise density ratio of 70 dB-Hz—1.9 picowatts in shot-noise-limited detection. This work shows, through modeling and simulation, that the optical power level required to perform robust measurement varies significantly between mission configurations. Alternate configurations, such as retro-reflector-based schemes, can operate robustly down to much lower carrier-to-noise density ratios, with the example parameters considered here: down to 29 dB-Hz—150 attowatts in shot-noise-limited detection. These results motivate exploration of alternate missions configurations with revised optical power requirements, increasing the feasibility of new designs. [ABSTRACT FROM AUTHOR]

Turkish economy has experienced significantly international factor movements especially in the 21st century. How these factor movements affect the production in the sectoral level draws attention as an essential research question. In this study, how factor movements affect the production in the sectoral level in the framework of Rybczynski which is one of the main results of Heckscher-Ohlin theory. Although Rybczynski theorem is tested for several countries, we have not encountered any study implemented for Türkiye. It is expected that this study will contribute to the relevant literature in this regard. In line with this purpose, impacts of factor movements are analyzed for Türkiye’s 47 ISIC industries in 2-digits from 2000 to 2014. Industries are divided into 3 categories: labor-intensive, capital-intensive and medium-intensive. Industries are divided as treatment group and control group based on their intensities and difference-in differences gravity specification is applied to test Rybczynski theorem. The results indicate the existence of the reverse Rybczynski effect. [ABSTRACT FROM AUTHOR]

In this paper, we will manifest how polytropic fluids produce effects on an alternate gravitational source, regardless of its features, for spherically symmetric and static spacetimes. For this purpose, we use f (T ,) modified gravity, which is characterized by the trace of an energy–momentum tensor as and torsion scalar T , Additionally, using the polytropic equation of state, we will speculate about the distribution of energy among fluids within an astrophysical object. We offer a thorough methodology for identifying generic relativistic polytropes accompanied by the minimal geometric decoupling technique. Ultimately, a few tangible attributes of polytropes along with perfect fluids are observed using the Tolman IV solution, including total pressure, energy interchange, and thermal characteristics. [ABSTRACT FROM AUTHOR]

The study is dedicated to geological interpretation of high-resolution seismoacoustic data acquired in the Central Atlantic during cruise 60 of the R/V Akademik Ioffe. Seismic facies of abyssal plane deposits, contourites, gravitites, and sediment waves have been identified based on specific characteristics of the seismic structure of the upper sediment cover. Geological interpretation was conducted considering the results of lithological studies of sediment cores collected during research cruises of the Shirshov Institute of Oceanology, Russian Academy of Sciences, as well as deep-sea drilling data. The role of gravity-driven processes in the formation of near-surface deposits is most significant in the region adjacent to the continental margin of South America. In the entire study area, bottom currents are considered as one of the main agents of sediment cover formation, responsible both for the deposition of contourite drifts and stratified hemipelagic sediments. [ABSTRACT FROM AUTHOR]

The geoid serves as a critical reference surface for precise mapping applications, particularly in the context of satellite-based positioning systems like the Global Navigation Satellite System (GNSS). While GNSS offers efficient positioning solutions, it relies on an ellipsoidal surface that lacks physical meaning for vertical reference, highlighting the need for accurate geoid height models. A precise geoid model is essential for converting geodetic heights into orthometric heights, which are crucial for practical applications. This study investigates potential discrepancies among geoid models derived from different methods, focusing on the Stokes-Helmert (SH), remove-compute-restore (RCR), and Kungl Tekniska Högskolan (KTH) methods. The primary differences among these methods lie in their approaches to modifying the Stokes formula and their reduction schemes. Conducted in the central part of Java Island, Indonesia, this study uses terrestrial gravity observations to model the geoid and GNSS/leveling data for validating the geoid models. The RCR method demonstrated the highest accuracy, with an RMS error of 8.4 cm, outperforming the KTH method (9.2 cm) and the SH method (10.7 cm). Discrepancies between SH and RCR models were less pronounced, with differences around 30 cm, compared to over 1 meter between KTH and the other methods. The comparison with the global EGM2008 model showed that the gravimetric geoid models were more accurate, with RMS differences reaching up to 10 cm, primarily due to systematic differences with the EGM2008 model. Statistical analysis using t-tests with 95% confidence intervals indicated that the differences among SH, RCR, and KTH methodologies were not statistically significant. Despite the RCR method's apparent superior performance, these differences did not achieve statistical significance. The study notes the limitations of using a relatively limited terrestrial gravity dataset and emphasizes the need for incorporating additional gravity data, such as recent airborne gravity datasets, to improve geoid model performance. Future research should also aim for denser GNSS/leveling observations with stricter measurement requirements to provide a more robust absolute assessment of gravimetric geoid models. [ABSTRACT FROM AUTHOR]

A sedimentary basin is a depression where sediment deposits accumulate and can act as a reservoir for the sedimentation and maturation of sediments containing hydrocarbons. The Bengkulu Basin is one of the forearcs in Indonesia. The Bengkulu Basin is one of the basins with the potential to have hydrocarbon reserves marked by an oil show in the Padang Capo village. Exploration to find a basin or hydrocarbon trap can be done using the gravity method. This method is often used to study the structure, bedrock, rock intrusion, and sedimentary basins based on variations in the earth's gravitational field due to lateral density differences which are known as anomalies gravitational. Determination of the existence of a hydrocarbon trap structure is carried out by derivative analysis, namely First Horizontal Derivative (FHD) and Second Vertical derivative (SVD) graphs and 2D modeling using forward modeling. The results of the analysis of the FHD and SVD graphs with 2D modeling show synchronous results. Where the analysis of the FHD and SVD graphs in the study area found many fault structures and folds. The study area is dominated by the fault type of thrust fault. In the 2-dimensional modeling of the research area where there is an oil show, it is found that there is a rising fault structure and the presence of anticline and syncline structures that could act as hydrocarbon traps. [ABSTRACT FROM AUTHOR]

The present study investigates the structure-property relationship of gravity die-cast and rheocast in situ processed 1wt%TiB2/Al-3.5Mg-0.15Sc-0.075Zr composites. The reinforcement was synthesized via the reaction of fluoride salts (K2TiF6 and KBF4) in the melt at 750 °C for an hour. The cooling slope technique was used for rheocasting, wherein the melt (pouring temperature of 700 °C) was allowed to flow over the cooling slope at an angle of 60°. Thereafter, all samples (gravity die cast and rheocast) were aged at 300 °C for 5 h. Microstructural characterization, hardness measurements, tensile tests, and fractography were necessary supplements to this investigation. The results obtained from this investigation infer: (a) The presence of nano-TiB2 particles increases the ductility (15%) of the gravity die-cast specimens; (b) rheocasting increases the strength of the specimen due to transformation from dendritic to equiaxed dendritic morphology and uniform particle distribution (reduced agglomeration). (c) Rheocast and aged specimens show maximum strength and adequate ductility due to the combined effects of structure refinement, reduced agglomeration, and the formation of fine precipitates. [ABSTRACT FROM AUTHOR]

This paper reports on an original set of direct sound speed measurements collected with the acoustic coring system in the New England Mud Patch (NEMP) and shelf break area to the south. Cores collected within the NEMP show range-dependence of the mud with slower sound speed and lower attenuation on the west side. In the shelf break region, the highest sound speeds are observed between the 200- and 350-m isobaths. The depth-dependence of the mud layer in the NEMP includes a surficial layer with a negative sound speed gradient of 28 s−1. The remainder of the mud column has a weak positive sound speed gradient of 6.2 s−1 over an isovelocity layer. Comparison between in situ and ex situ sound speed measurements provides an assessment of the effects of sediment disturbance from gravity coring operations. Small differences in the upper 2.5 m were attributed to the changes in the geoacoustic properties caused by disturbance from the coring process. Below 2.5 m, the average difference is close to zero, suggesting that these sediments were minimally disturbed. Finally, an in situ measurement of shear speed was obtained near the depth of maximum penetration. The shear speed was well correlated with sound speed from approximately the same depth interval. [ABSTRACT FROM AUTHOR]

In the present work, an extended description of the covariant noncommutative space is presented, which accommodates the Fuzzy Gravity model constructed previously. It is based on the historical lesson that the use of larger algebras containing all generators of the isometry of the continuous one helped in formulating a fuzzy covariant noncommutative space. Specifically a further enlargement of the isometry group leads the authors, in addition to the construction of the covariant noncommutative space, also to the suggestion of the group that should be gauged on such a space in order to construct a Fuzzy Gravity theory. As a result, two Fuzzy Gravity models are obtained, one in de Sitter and one in anti‐de Sitter space, depending on the extension of the isometry group, and their spontaneous symmetry breaking leading to fuzzy versions of the noncommutative SO(1,3)$SO(1,3)$ gravity are discussed. In addition, how to introduce fermions in the fuzzy gravity is discussed for the first time, and even more importantly, how to unify the constructed noncommutative‐fuzzy gravity with internal interactions based on SO(10)$SO(10)$ or SU(5)$SU(5)$ as grand unified theories. [ABSTRACT FROM AUTHOR]

The authors show that in the f(Q)$f(Q)$ gravity with a non‐metricity scalar Q$Q$, the curvatures in Einstein's gravity, that is, the Riemann curvature constructed from the standard Levi‐Civita connection, could not be excluded or naturally appear. The first observation is that even in f(Q)$f(Q)$ gravity, the conservation of the matter energy‐momentum tensor is not described by the covariant derivatives in the non‐metricity gravity but that is given by the Levi‐Civita connection. The commutator of the covariant derivatives in Einstein's gravity inevitably induces the Riemann curvature. There is no symmetry nor principle which prohibits the Riemann curvature in non‐metricity gravity. Based on this observation, the authors propose and investigate fQ,G$f\left(Q, \mathcal {G} \right)$ gravity with the Gauss–Bonnet invariant G$\mathcal {G}$ and its generalizations. The authors also show how fQ,G$f\left(Q, \mathcal {G} \right)$ models realizing any given the Friedmann–Lemaître–Robertson– Walker (FLRW) spacetime can be reconstructed. The reconstruction formalism to cosmology is applied. Explicitly, the gravity models which realize slow roll or constant roll inflation, dark energy epoch as well as the unification of the inflation and dark energy are found. The dynamical autonomous system and the gravitational wave in the theory under investigation are discussed. It is found the condition that the de Sitter spacetime becomes the (stable) fixed point of the system. We show that in the f(Q)$f(\mathcal{Q})$ gravity with a non‐metricity scalar Q$Q$, the curvatures in Einstein's gravity, that is, the Riemann curvature constructed from the standard Levi‐Civita connection, could not be excluded or naturally appear. The first observation is that even in f(Q)$f(\mathcal{Q})$ gravity, the conservation of the matter energy‐momentum tensor is not described by the covariant derivatives in the non‐metricity gravity but that is given by the Levi‐Civita connection. The commutator of the covariant derivatives in Einstein's gravity inevitably induces the Riemann curvature. There is no symmetry nor principle which prohibits the Riemann curvature in non‐metricity gravity. Based on this observation, we propose and investigate f(Q,G)$f({\mathcal{Q},\mathcal{G}})$ gravity with the Gauss–Bonnet invariant G$\mathcal{G}$ and its generalisations. We show how f(Q,G)$f({\mathcal{Q},\mathcal{G}})$ models realising any given the Friedmann–Lemaître–Robertson– Walker (FLRW) spacetime can be reconstructed. We apply the reconstruction formalism to cosmology. Explicitly, the gravity models which realise slow roll or constant roll inflation, dark energy epoch as well as the unification of the inflation and dark energy are found. The dynamical autonomous system and the gravitational wave in the theory under investigation are discussed. It is found the condition that the de Sitter spacetime becomes the (stable) fixed point of the system. [ABSTRACT FROM AUTHOR]

Shear stress levels on reverse faults are anticipated to be several times higher than on normal faults with the same pore pressure ratio. In addition, ruptures on normal faults release gravitational potential energy, whereas earthquakes on reverse faults expend work in uplifting rocks. In this study, I investigate the significance of these differences for earthquake cycles and I question whether the source of energy driving earthquakes is the same on reverse and normal faults. Based on the assumption that normal and reverse faults have the same background frictional properties and pore pressure states, I use numerical simulations with a two‐dimensional dynamic elastic‐plastic model to show that due to stress differences, earthquakes on reverse faults tend to occur less frequently, produce more coseismic slip and stress drop and involve higher slip rates than ruptures on normal faults with equivalent dimensions. The analysis also shows differences in the energy changes associated with earthquake cycles on reverse and normal faults. However, the earthquakes on both fault types result from abrupt release of elastic strain energy, which proceed and essentially drive variations in gravitational potential energy. Thus, ruptures on both normal and reverse faults are consistent with elastic rebound theory. Plain Language Summary: Normal faults found in regions experiencing extension are normally thought to have lower stress levels than reverse faults in zones of convergence. In addition, whereas the action of normal faulting causes mostly subsidence and is therefore assisted by gravity, reverse faulting tends to uplift topography, which requires that work be done against gravity. This study uses numerical modeling to address whether there are significant differences in the earthquakes on reverse and normal faults, assuming that they have identical pore pressures and frictional properties. The results show that ruptures on reverse faults are larger, more energetic and less frequent than earthquakes on normal faults. These differences are due to the higher stress levels on reverse faults than normal faults with the same dimension. The results also show than although earthquakes on normal faults are assisted by gravity, they result from an abrupt drop in elastic energy in the same way as ruptures on reverse faults. Thus, the results do not support claims that earthquakes on normal faults have a different energy source and require an explanation other than elastic rebound. Key Points: Model earthquakes on reverse faults involve higher slip rates, more slip, and larger stress drop and occur less frequently than on normal faultsModel earthquakes on both fault types involve abrupt release of elastic strain energy, much of which is dissipated plasticallyDespite differences in energetics, model earthquakes on both fault types are consistent with elastic rebound theory [ABSTRACT FROM AUTHOR]

The blind and exposed salt domes in the Fars Arc of the south-eastern Zagros Fold and Thrust Belt, are rooted in the Precambrian–Early Cambrian Hormuz Salt, which deposited over a Precambrian crystalline basement. To define the subsurface blind salt domes and examine the influences of the basement morphology on the distribution of the salt domes and their impact on hydrocarbon accumulation, we used high–resolution terrestrial magnetic and gravity data. Applying various derivative–based filters on the Bouguer gravity anomalies we identified seven blind salt domes. From those, two have characteristic topographic implications and another three have been also imaged by the earlier seismic studies. A low Bouguer anomaly with a prominence sharp variation limits the western extent of the overlying allochthonous Late Oligocene–Early Miocene Fars Salt layer. The horizontal derivative of the Bouguer anomaly highlights a distinctive lineament in the south of the Bander–e–Lengeh anticline, which is interpreted as the effect of the Fars Salt layer on folding and faulting propagation. The magnetic anomalies were not effective for detecting blind salt domes due to the presence of highly magnetised crystalline basement rock fragments within salt domes, yielding an unexpected non-zero susceptibility value similar to the surrounding sedimentary layers. This indicates the influence of crystalline basement dynamics on salt tectonism in the study area. The N–S trend of the long-wavelength magnetic anomaly of the Hendurabi Lineament extends east of the study area and reflects a basement structure. The integrated E–W gravity–magnetic forward modelling implies an N–S trending horst–graben structure in the crystalline basement, which controls the thickness of the Hormuz salt and possibly the distribution of salt domes. [ABSTRACT FROM AUTHOR]

The free-floating objects in Celan's 1960s poems are more than astronomical and mystical phenomena; read ontologically, they reveal the imprint of Nietzschean nihilism. The loss of gravity in Celan's middle and later poetry ciphers his dizzy sense of living in a postwar Europe where he has to work through fallen values by opening his poetry up to unknown configurations and dimensions of nihil. Although Celan is reluctant to resort to Will to Power to fight nihilism, he seeks to give space for the nothing, to make sense (if not a meaning) out of it in light of Nietzschean Eternal Return. His free-floating astral bodies, simultaneously embodying the heaviness and lightness of being, maintain nihil in an open, poetic, non-nihilistic atmosphere where nihil is set in motion but de-absolutized in the poetic horizon. [ABSTRACT FROM AUTHOR]

Several satellite gravity anomaly models are freely available to calculate the free‐air gravity anomaly in areas where shipborne gravity measurements are scarce. Two models produced by the Technical University of Denmark (DTU17) and the Scripps Institution of Oceanography (SIOv32.1), respectively, were selected to compute the free‐air anomalies over the Cosmonaut Sea, East Antarctica. A statistical comparison analysis was performed to evaluate the resolution of satellite gravity anomaly models by comparing them with the shipborne surveying date. The radially averaged energy spectra of free‐air anomaly from different sources were calculated and compared over two selected regions to further evaluate the reliability of the data derived from satellite gravity anomaly models. The satellite gravity anomaly models have a better resolution in the ocean basin than in the area near the continental shelf. The comparison analysis revealed that the precision of both DTU17 and SIOv32.1 is close to the shipborne gravity data, but on average, SIOv32.1 is a little bit better than DTU17. The spectral analysis showed that the shipborne measurements may provide higher resolution than the satellite gravity anomaly model at wavelengths shorter than 20 km, and the free‐air data derived from SIOv32.1 have better resolution than the one from DTU17. These shipborne datasets will provide contributions for the updates of the Antarctic gravity anomaly and enable new high‐resolution combined Earth gravity models to be derived in Antarctica. [ABSTRACT FROM AUTHOR]

The gravimetric forward method is crucial in geophysical applications for a gravimetric interpretation of the Earth's inner structure. In this study, we present the gravimetric forward modelling open‐source software that incorporates a graphical user interface. This software allows data preparation, manipulation and result interpretation both spatially and spectrally. For spatial domain modelling, it uses prism and tesseroid elements, whereas in the spectral domain, it extends Parker's formulas within specified boundaries. The software's utility is demonstrated through synthetic models and real‐world applications, including calculating corrections for topography, sediments and consolidated crust using ETOPO1 and CRUST1.0 models. Performance comparisons show that Parker's method delivers computation speed superior to that of the prism, tesseroid and Terrain gravity forward (TGF) software, with variances ranging within ±12 mGal for Gz${{G}_z}$ and ±0.3 E for Gzz${{G}_{zz}}$ across different geological scenarios. [ABSTRACT FROM AUTHOR]

The calculation of the vertical derivatives of potential field methods can be carried out in a stable manner by Tikhonov regularization, but this procedure requires the appropriate selection of a regularization parameter. For this purpose, we introduce a criterion based on Morozov's discrepancy principle that uses a preliminary approximation given by the vertical derivative of the smoothed data. The smoothing may be performed by a physical or a mathematically based low‐pass filter. The filtered data are computed only for estimating the regularization parameter; once it is found, we evaluate the regularized vertical derivative from the original data (not from the smoothed one) in the frequency domain. We verified from experiments with noise‐corrupted synthetic data, as well as gravity and magnetic field data, that the regularized vertical derivative has about the same smoothness as the one obtained from filtered data, but true anomalies are more easily distinguished from noise and the shapes of the anomalies are better preserved. [ABSTRACT FROM AUTHOR]

In this paper, the Green-Lindsay theory is used to study two-dimensional interactions in fibre-reinforced orthotropic magneto-thermoelastic media with temperature dependence and gravity. Formulations are subjected to mechanical stress. An exact solution to the problem is achieved by applying normal mode techniques. In addition, comparisons were made to analyze the effects of temperature-dependent properties, gravity, magnetic field, time and gain parameters. Displacement, stress and temperature components are numerically calculated for appropriate materials and presented graphically. Graphical results show that reinforcement, gravity, magnetic field, temperature-dependent properties and time have a significant influence on the distribution of all physical quantities. Some interesting special cases emerge from this report. [ABSTRACT FROM AUTHOR]

The Brans-Dicke scalar-tensor theory of gravity (Phys. Rev. 124, 925: 1961) is applied in this work to study the Sharma-Mittal holographic dark energy on a background of anisotropic and spatially homogenous Bianchi type-II spacetime. In this scenario, the Brans-Dicke scalar field ϕ is used as a function of the average scale factor a(t). To explore the universe's accelerated expansion, the physical behaviour of the model is addressed through a graphical representation. Furthermore, squared sound speed 2 s v is used to verify the stability of the models. The popular cosmic plane de de ωde - ω'de is built for our models. It's also important to note that all the findings are in line with current observational data. [ABSTRACT FROM AUTHOR]

Feeding strip significantly enhances continuous cast slab quality. To clarify its impact on inclusion distribution, a mathematical model coupling flow, solidification and inclusion motion have been developed. The upper recirculation, lower recirculation, and unformed recirculation flow occur during continuous casting. Under the resultant forces of drag, virtual mass, pressure gradient, Saffman, gravity, buoyancy, etc., the inclusion motion can be divided into two stages: Injection and Split flow. Feeding strip mainly affects inclusion motion by altering the drag, virtual mass, pressure gradient, and Saffman forces, which are closely related to the molten steel flow. After feeding strip, the lower recirculation on the strip feeding side is compressed, while it on the no-feeding side is expanded. The unformed recirculation flow on strip feeding side squeezes the flow below lower recirculation on no-feeding side. A higher strip feeding speed promotes downward inclusion motion, increasing the chance of being captured between the slab edge and strip. Unformed recirculation flow guides inclusions on the no-feeding side toward the slab edge, while expanded flow directs them toward the center. Consequently, inclusions on strip feeding side gradually gather between slab edge and quarter, while inclusions on no-feeding side first gather toward center and then toward edge of slab with increased strip feeding speed. [ABSTRACT FROM AUTHOR]

Based on one-dimensional water hammer theory and combined with an engineering example, the selection of the flow characteristics of the end control valve of gravity flow system with wide-range flow variation is numerically studied from three aspects: the influence of flow characteristics of control valve on its steady-state opening-degree, the determination of the most unfavorable flow conditions of valveclosing water hammer, and the influence of flow characteristics of contrive valve on valve-closing water hammer. And the flow characteristics of linear type, parabola type and equal percentage type are compared. The results show that: 1 The equal percentage flow characteristic is more conducive to the stable operation of the control valve under the low flow condition. Under this condition, the steady-state opening-degree of the equal percentage type control valve is larger, which can avoid cavitation and vibration caused by too small opening. 2 The most unfavorable flow condition of the valve-closing water hammer should consider the minimum initial flow condition, under which the water hammer pressure of the input point of the control valve is largest because of the largest initial pressure and the shortest closing time. 3 The equal percentage flow characteristic is more conducive to reducing the control valve-closing water hammer pressure. Under the same initial flow rate and valve closing rate, the control valve with equal percentage type flow characteristics has a larger initial opening-degree, a longer actual closing time, and a smaller change gradient of flow coefficient in the small opening-degree range, so the extreme value of the valve-closing water hammer pressure is smaller, which is more conducive to pipeline safety. [ABSTRACT FROM AUTHOR]

Finned-tube heat exchanger (FTHE) is often used as an evaporator in commercial products of separated heat pipe (SHP). The working conditions of FTHE in gravity-assisted SHP are significantly different from those working in refrigerators and air conditioners. Although FTHE is widely used in commercial products of SHP, previous research on its characteristics is very limited. In this paper, a mathematical model for a SHP with FTHE as the evaporator and plate heat exchanger as the condenser is established and verified with experiments. Parametric analyses are carried out to investigate the influences of evaporator design parameters: air inlet velocity, number of tube rows, tube diameter, and fin pitch. With the increasing of air velocity, number of tube rows and tube diameter, and the decreasing of fin pitch, the heat transfer rate increases, while the energy efficiency ratio (EER) decreases monotonically. Using the total cost of the ten-year life cycle as the performance index, the structure parameters of the evaporator with a given heat transfer rate are optimized by the method of orthogonal experimental design. It is found that the total cost can differ as large as nearly ten times between groups. Among the three factors investigated, the number of tube rows has a significant impact on the total cost of the evaporator. With more tube rows, the total cost will be less. The impacts of fin pitch and tube diameter are insignificant. These results are of practical importance for the engineering design of FTHE in gravity-assisted SHP. [ABSTRACT FROM AUTHOR]

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The gravity model is the workhorse model of trade. Yet, many economists still view gravity as a reduced‐form estimating equation and apply it without guidance from theory, while others are skeptical about its usefulness for counterfactual projections. This paper offers a historical overview of the evolution of gravity, from an a‐theoretical application to an estimating computable general equilibrium model, which can be nested in more complex frameworks. Along the way, I address some misconceptions about gravity, summarize the current recommendations for gravity estimations, highlight properties that have made gravity so successful, and review the latest contributions to the related literature. [ABSTRACT FROM AUTHOR]

The present note addresses the novel problem of executing complex aircraft maneuvers under considerable center of gravity (c.g.) uncertainties arising from asymmetrical loading or release of payloads, uneven fuel consumption etc. First, the aircraft flight dynamics under predominantly lateral c.g. movement, is approximated and expressed in a block strict feedback form and thereafter an adaptive backstepping controller is proposed to adapt to the c.g. variations. To alleviate the model uncertainty caused by this model approximation and also to provide robustness to aerodynamic uncertainties in high-alpha regions, a sliding mode control is further integrated with the adaptive backstepping control law. Asymptotic stability conditions of the proposed controller are derived from the first principle using Lyapunov's method and Barbalat's lemma. To validate the proposed control scheme, the high-alpha Herbst maneuver is implemented in simulation for the F18-HARV aircraft and the results show that the maneuver performance remains nearly the same under both the nominal and the off-nominal c.g. positions. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the dependability of double-star induction machines by employing meticulous monitoring and intelligent handling of potential electrical malfunctions that may arise during their functioning. Specifically, the research delves into the examination of three distinct fault types: rotor bar breakage, stator phase opening, and inter-turn short circuit. Utilizing a mathematical model developed in the natural reference frame (abc), our aim is to comprehensively delineate both normal and faulty operational scenarios. To categorize and gauge the gravity of identified faults, we employ a methodology rooted in spectral analysis. In order to ensure continuous machine operation, especially in instances of stator phase opening, our proposed mitigation approach entails intentionally opening a secondary phase positioned at a 90-degree angle to the faulty phase. This strategic alteration transforms the machine into a dual two-phase configuration. Through rigorous simulation analyses, our findings underscore the efficacy and pragmatic viability of the devised fault detection technique, offering valuable insights into the domain of electrical machine reliability and fault management. [ABSTRACT FROM AUTHOR]

Linear gravity anomalies (LGAs) on the Moon have been interpreted as ancient magmatic intrusions formed during the lunar expansion. The composition of such ancient subsurface intrusions may offer hints for the lunar thermodynamic state in the initial stage of lunar history. To pose a first compositional constraint on magmatism related to lunar expansion, this study analyzed the spectrum and gravity around craters on LGAs, such as Rowland, Roche, and Edison craters. Using reflectance spectra around the craters, we first surveyed non‐mare basaltic exposures. To test the LGA excavation scenario as a possible origin of the discovered exposures, we then compared the Gravity Recovery and Interior Laboratory data and post‐cratering gravity simulation with the iSALE shock physics code. Our spectral analysis reveals no basaltic exposure around the Rowland crater. Further, the observed termination of LGA at the crater rim contradicts the gravity simulation, which assumes that LGA predates the Rowland crater. These results suggest that LGA formation might postdate the Rowland formation and that lunar expansion lasted even after the Nectarian age. On the other hand, we found that both Roche and Edison craters possess basaltic exposures in their peripheries. Because the gravity reduction inside Roche crater can be reproduced in our simulation, the discovered basaltic exposures are possibly LGA materials ejected from these craters. The composition of those exposures shows that the LGA intrusions at the two locations are composed of low‐titanium magma, indicating that ancient magma during the expansion did not contain ilmenite‐rich melt, perhaps resulting from the low‐ilmenite content of the ancient upper mantle. Plain Language Summary: The Moon has positive, narrow, and long gravity anomalies, so‐called linear gravity anomalies (LGAs), which are thought to be magmatic intrusions formed during the ancient lunar expansion. The composition of these intrusions may provide insights into the early lunar thermal state. This study analyzed the reflectance spectra and gravity data around craters located on LGAs, specifically Rowland, Roche, and Edison craters, which are postulated to have ejected the LGA material. By analyzing the reflectance spectra, we first identified non‐mare basaltic exposures that likely originated from these subsurface formations. We next examine if these exposures are composed of the LGA materials by comparing the observed gravity with cratering simulation results. We found no basaltic exposures around Rowland and that gravity inside Rowland is not consistent with the excavation hypothesis, perhaps suggesting that LGA formation and lunar expansion occurred after the Rowland formation. On the other hand, we discovered basaltic exposures around both Roche and Edison craters, which can be interpreted as ejecta from the LGAs consistent with the gravity inside Roche crater. The composition of these exposures indicates that LGAs are composed of low‐titanium magma, which provides a new constraint on the ancient thermal state of the Moon. Key Points: High‐calcium pyroxene exposures and gravity reduction around Roche crater imply an excavation of lunar linear gravity anomaly materialsLunar subsurface dikes formed during the ancient expansion stage are estimated to be composed of low‐titanium magmaA linear gravity anomaly possibly postdates the Rowland crater, suggesting a potential prolongation of lunar expansion beyond the Nectarian age [ABSTRACT FROM AUTHOR]

This work is a theoretical investigation into the effect of finite droplet inertia on combined gravitational and thermocapillary interactions of spherical drops covered with an incompressible surfactant film. The significance of droplet inertia is indicated by the magnitude of the Stokes number St. Initial calculations are a continuation of previous results from St = 0 to finite Stokes numbers at O (1) drop-to-medium viscosity and thermal conductivity ratios. Interesting outcomes, such as stable tandem motion and complex relative trajectories, are observed. At more realistic O (10) ratios, the results tend to be dampened from those at lower values, although unusual behavior still occurs. Finally, interactions are determined for two physical systems, water drops in air and mercury drops in n-pentane. At normal gravity, two limits are usually possible. In order for the thermocapillary and gravitational contributions to be equal, the drops and their corresponding Stokes numbers must be small, while for larger drops at higher St, gravity is the dominant driving force. For water droplets in air with radii less than 10 μ m, van der Waals forces control the interactions. However, drop inertia is the most important factor for droplets with radii greater than 25 μ m. Even a small thermocapillary effect can have noticeable consequences on the relative trajectories for intermediate-sized drops. Some comments are made on the difficulty in experimentally reproducing the theoretical results, with a recommendation of centi- or milligravity conditions. [ABSTRACT FROM AUTHOR]

Purpose: The present study has depicted the effect of gravitational on a two-temperature nonlocal poro-thermoelastic solid. Methods: The multi-phase-lag model and fractional derivatives are used to tackle the issue. Through normal mode analysis, analytical formulas for the variable fields are derived. Using appropriate boundary conditions, the physical fields are calculated and the numerical computations have been carried out with the help of MATLAB programming. Results: Through a careful comparison of the numerical data, the impacts of gravity, fractional derivative order, and locatiy on the behavior of physical fields are described. Conclusion: Physical variables are affected by nonlocal thermoelasticity, fractional derivative order as well as the gravity field. [ABSTRACT FROM AUTHOR]

Purpose: Considering the transportation structure in the factory is responsible for transporting materials, thus when analysing the axially moving characteristics of the conveyor belt in operation, the effect of the load must be considered. Methods: Based on Von Karman's nonlinear plate theory, the motion equations of the system are established using the assumed mode method and Hamilton's principle. The effects of the concentrated mass positions on the dynamic characteristics of the system are analyzed. The stability properties of the system are analyzed by solving the generalized eigenvalue problem. The amplitude–frequency response curves of the transverse generalized displacements of the system are drawn and analyzed by numerical calculation. Results: The effects of the concentrated mass position, the axially moving velocity, and the external excitation amplitude on the nonlinear amplitude–frequency responses of the system are studied. The results show that the concentrated mass position has significant effects on the natural frequency of the system. All the amplitude–frequency response curves of the system under the harmonic excitation show the hardening type nonlinearity. The concentrated mass and the axially moving velocity have a great influence on the first- and second-order resonances of the system. With the excitation amplitude, axially moving velocity, and concentrated mass changing, the system appears complex nonlinear response phenomena. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper is devoted to observe the physical attributes of static spherically symmetric isotropic compact stellar candidates in the context of Rastall theory of gravity. In order to inspect the structural composition of compact objects, the Heintzmann ansatz is taken into account. The unknown parameters associated with Heintzmann ansatz are evaluated through matching conditions with derived values of radii and masses of some specific star models. The consistency of the adopted ansatz is analyzed via graphical interpretation of matter variables, equation of state parameter, mass components, energy constraints, causality condition, stellar equation and adiabatic index for several choices of Rastall parameter. It is observed that the stars under consideration manifest stable structures corresponding to Heintzmann ansatz in this framework. Moreover, it is shown that for vanishing Rastall coupling parameter, the standard outcomes of general relativity can be retrieved. [ABSTRACT FROM AUTHOR]

A new definition of entropy is introduced using a model that simulates an expanding space-time compatible with the fundamental principle of cosmology. The entropy is obtained by mean of a state function that measures the variation of the space-time normal curvature, from a highly compressed space to a lower compressed space. The defined entropy leads to work out a new understanding of the earliest conditions that last for a period estimated to 380,000 years after the Big Bang. It leads to understand via a short period of inflation the process that generates the uniform distribution of matter and energy at the surface of the last scattering. It involves gravitational singularities in a process of gradual decompression propitious to the incubation of matter recombination, and it allows to trace back gravity origin. [ABSTRACT FROM AUTHOR]

In this paper, our purpose is to investigate the anisotropic stellar structure caused by f (R , ϕ) modified gravity, where R represents the Ricci scalar and ϕ represents the scalar potential. This study emphasizes the impact of static spherically symmetric stellar structures using anisotropic distribution. Furthermore, an anisotropic matter source is employed to explore the stability of star formations. To get the value of unknown parameters of the compact structures, we compare the Schwarzschild metric to external geometry. Moreover, we examine the physical attributes of compact objects by presuming a viable f (R , ϕ) = ϕ (R + α R 2) gravity model. We analyze the graphical behavior of density and pressure, the Tolman–Oppenheimer–Volkov equation, energy conditions, mass function, surface redshift, and adiabatic index. It is recognized that all the obtained results deliver emphatic evidence for the stability of our considered realistic stars. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the bouncing behavior of the universe within the framework of f (R , L m) gravity, using a simple form of f (R , L m) = R 2 + L m γ (where γ is a free model parameter) as previously studied. The model predicts a vanishing Hubble parameter in the early and late times, with the deceleration parameter approaching a specific limit at the bouncing point. The EoS parameter is observed to cross the phantom divide line (ω = − 1) near the bouncing point, indicating a significant transition from a contracting to an expanding phase. The model satisfies the necessary energy conditions for a successful bouncing scenario, with violations indicating exotic matter near the bouncing point. Stability conditions are satisfied for certain values of γ near the bouncing point, but potential instabilities in late-time evolution require further investigation. Finally, we conclude that the f (R , L m) gravity model is promising for understanding the universe's dynamics, especially during events like the bouncing phase. [ABSTRACT FROM AUTHOR]

The objective of this paper is to deal with physical features of charged anisotropic compact objects in the framework of f(R,ϕ,X) modified theory of gravity. To accomplish the desired objective, we consider a spherically symmetric spacetime with charged anisotropic fluid distribution. In addition, we utilize the Krori–Barua metric, i.e. λ(r)=Xr2 + Y and β(r) = Zr2 for exploring the field equations. Moreover, we compare the interior boundary to the bardeen model as an exterior geometry to calculate the unknown constrains. Further, to check the existence of bardeen stellar structure, we discuss the behavior of physical properties such as energy density, pressure components, anisotropy, equation of state parameters, stability analysis, energy bounds, equilibrium condition, adiabatic index, compactness factor and surface redshift. Conclusively, all the obtained results show that the system under consideration is physically stable, free from singularity and viable. [ABSTRACT FROM AUTHOR]

This study deals with the physical aspects of the gravitationally decoupled solutions under f (ℛ) gravity scenario. In doing so, charged anisotropic matter composition is assumed as the parent (seed) source for the static spherically symmetric configuration. Commencing with the Kuchowicz ansatz for the charged static parent matter formation, we establish the Karmarkar condition to thoroughly address the deformed functions and the gravitational aspects of the compact spheres. Besides these, null-complexity and isotropized conditions will enforce to grasp the system's stability by the inclusion of charge and ℛ + ϖ ℛ 2 factors through graphical trends. [ABSTRACT FROM AUTHOR]

Carbon nanotube fibers (CNTFs) are considered an ideal candidate as next‐generation conducting wires due to their high conductivity and low density. However, the orientation and compaction of the nanotubes in a CNTF need to be further improved to achieve even higher conductivity and ampacity. Here the fabrication of double‐wall CNTFs (DWCNTFs) is reported by a dry‐jet wet spinning method, which significantly improves the orientation and compaction of the carbon nanotubes (CNTs). As a result, the obtained DWCNTFs have a record high electrical conductivity of 1.1 × 107 S m−1 and ampacity of 8.0 × 108 A m−2. The fibers also have a high tensile strength of 1.65 GPa and a toughness of 130.9 MJ m−3, among the highest for wet‐spun CNTFs. The DWCNTFs preserve their integrity and conductivity after more than 5000 bending cycles. Theoretical calculations indicate that in a dry‐jet wet‐spinning process, gravity promotes the orientation of the CNTs along the axial direction of the fiber. [ABSTRACT FROM AUTHOR]

Lifting individual water droplets against gravity without external energy input is reported. Classical capillary rise requires the complete wetting of a transport pathway, resulting in water loss and poor collection efficiency. Boosting Laplace pressure propulsion while diminishing contact line pinning enables lossless water droplet ascension. Surfaces with properly designed physicochemical gradients can propel single water droplets as high as 65 mm against gravity, enabled by 1) surface wettability patterns, 2) liquid‐like polymer brushes, and 3) controlling droplet size within a shorebird beak‐inspired wedge geometry. Surface wettability patterns induce droplet elongation toward the gap‐to‐apex direction of the wedge geometry, which boosts Laplace pressure propulsion by increasing droplet length and diminishes contact line pinning by decreasing droplet width. Polymer brushes for wettability patterning exhibit minimal contact angle hysteresis, minimizing contact line pinning and enabling residue‐free droplet ascension. Controlling the droplet size prevents the dominance of either contact line pinning or gravity over Laplace pressure propulsion, enabling droplet transport against gravity. Utilizing these design rules, low surface tension n‐decane is also transported against gravity, and a particle‐laden solution is separated using sedimentation and against‐gravity transportation. Such surfaces may facilitate lossless, against‐gravity, and power‐free water pumps in numerous emerging sustainability and energy applications. [ABSTRACT FROM AUTHOR]

This research explores how filamentary objects behave when they collapse in the presence of exotic material. To accomplish this, we employ Palatini (R, T) theory as a candidate for exotic material. We derive the collapsing equation by enforcing the Darmois junction condition on the collapsed surface boundary. At this boundary, we obtain that the radial pressure is proportionate to the time‐dependent term of the field and is not zero. Lastly, we investigate the correlation between dark matter and gravitational waves and find that exotic terms disrupt the transmission of gravitational waves. It is worthwhile to mention here that our results (in both formalisms, metric approach and Palatini approach) reduce to (R) gravity and general relativity. [ABSTRACT FROM AUTHOR]

If modified gravity holds, but the weak lensing analysis is done in the standard way, we find that dark matter halos have peculiar shapes that do not follow the standard Navarro-Frenk-White profiles and which are fully predictable from the distribution of baryons. In this work, we study in detail the distribution of the apparent DM around point masses, approximating galaxies and galaxy clusters, along with their pairs for the QUMOND version of modified Newtonian dynamics, taking the external gravitational acceleration, ge, into account. At large radii, the apparent halo of a point mass, M, is shifted against the direction of the external field. When averaged over all lines of sight, the halo has a hollow center. Using a0 to denote the MOND acceleration constant, we find that its density follows ρ(r)=√Ma0/G /(4πr2) ρ (r) = M a 0 / G / (4 π r 2 ) between the galacticentric radii √GM/a0 G M / a 0 and √GMa0 / ge, G M a 0 / g e and then ρ ∝ r−7G2M3a03/ge5 at a greater distance. Between a pair of point masses, there is a region of a negative apparent DM density, whose mass can exceed the baryonic mass of the system. The density of the combined DM halo is not a sum of the densities of the halos of the individual points. The density has a singularity near the zero-acceleration point, but remains finite in projection. We computed maps of the surface density and the lensing shear for several configurations of the problem and derived formulas to scale them to further configurations. In general, for a large subset of MOND theories in their weak-field regime, for any configuration of the baryonic mass, M, with the characteristic size of d, the total lensing density scales as ρ(x) = √Ma0/Gd-2f(α,x / d,ged/ √GMa0) ρ ( x ) = M a 0 / G d − 2 f α , x / d , g e d / G M a 0 , where the vector α describes the geometry of the system. Detecting the difference between QUMOND and cold DM (CDM) halos appears to be possible with existing instruments. [ABSTRACT FROM AUTHOR]