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The limited velocity in a geometry of Lorentzian signature seem to prevent the universe to reach thermodynamic equilibrium as suggested by the cosmic microwave background. Thus it was suggested that the universe which was initially minuscule has reached a more considerable radius in a short duration by a process known as cosmic inflation. However, to drive such a process have led to the suggestion of an ad-hoc scalar field the inflaton, which has no purpose in nature other than driving the cosmic inflation field and then stopping it once the universe reached the right size. In a recent paper it was shown that rapid expansion can occur without postulating an inflation by following Hawking's suggestion and assuming that primordially the metric of the universe had an Euclidean signature, in which case velocity is not limited and thermalization and rapid expansion are derived without the need to assume an ad-hoc field. However, while in the previous work emphasis was put on the dynamics and physical statistics of the particles in a Euclidean space versus Lorentzian space in which both spaces were given. No mathematical model was given regarding the development of current Lorentzian space-time from the early Euclidean space-time, and how fundamental problems such as the space-time singularity and the homogeneity of the CMB can be solved in the hybrid Euclidean–Lorentzian picture. This lacuna is to be rectified in this paper. [ABSTRACT FROM AUTHOR]

In this paper, we have presented bulk viscous cosmological model of the universe in the modified gravity in which the Lagrangian of the gravitational action contains a general function F (T) , where T denotes torsion, for flat Friedmann–Robertson–Walker spacetime with isotropic fluid. We have studied cosmological solution in F (T) theory of gravity, especially of a particular preference F (T) = T + f (T) = (1 + γ) T + α T 2 , where γ and α are coupling constants, in the presence of bulk viscosity described by Eckart theory, Truncated Israel Stewart theory and Full Israel Stewart theory. The physical and geometrical prospectives of the models in Eckart, Truncated Israel Stewart theory and Full Israel Stewart theory are deliberated in details. The investigation of the variation of bulk viscous pressure, energy density, scale factor, Hubble parameter and deceleration parameter with cosmic growth is furnished in the relevant theories. The models are analyzed by comparison with recent observational data. The cosmological models are well-matched with observations. [ABSTRACT FROM AUTHOR]

In this paper, we review the main features of modified theories of gravity containing higher-order curvature invariants in the action. After summarizing the main features of these theories, we consider their applications to cosmology, pointing out the differences with respect to general relativity that can eventually solve issues exhibited by the latter at low and high energy scales. Specifically, we explore a gravitational action that incorporates both the Ricci scalar R and the topological Gauss–Bonnet term, denoted as . Our investigation revolves around the cosmological properties of a specific category of modified gravity theories, chosen upon symmetry considerations. Within the framework of a spatially flat, homogeneous and isotropic cosmic background, we demonstrate that it is possible to account for the presently observed acceleration of the Universe by means of the extra geometric terms carried by the selected f (R ,) model. This approach offers a way to address the issues associated with the cosmological constant. To achieve this, we first examine the energy conditions and find that, under certain choices for the values of the cosmographic parameters, these conditions are all violated. In the second part of the work, to assess the feasibility of the selected f (R ,) model, we place observational constraints on its free parameters through a Bayesian Monte Carlo technique applied to late-time cosmic data. Our findings reveal that the f (R ,) model can effectively reproduce observations at low redshifts, providing an alternative to the standard Λ CDM scenario. [ABSTRACT FROM AUTHOR]

The notion that nature is subject to laws is exciting from many different viewpoints. This paper is based on the context of modern cosmology. It will list the significant interdisciplinary implications generated by various aspects of the contemporary scientific discussion about the status of laws of nature, especially their dynamic nature. Recent work highlights how multiple aspects of the observed universe still lack explanation and that several problems of standard cosmology still form the object of debate. Considering these issues, several proposals have been made that entail a revision of the concept of the law of nature, according to which the nature of time and of the relation between causality and natural laws ought to be reconsidered using approaches or viewpoints which point to philosophical issues. We argue that Tim Maudlin's concept of Fundamental Law of Temporal Evolution (FLOTE) and Nancy Cartwright's notion of the nomological machine provide new insights and valuable tools that can be used in the analysis of the status of laws in the context of cosmology and of complex systems theory. The limits of the traditional approach to laws of nature and their mathematical formulation are highlighted in this context, as well as the fact that many of the ultimate properties of nature may turn out to be formally unpredictable or uncomputable. [ABSTRACT FROM AUTHOR]

A number of philosophers claim that realism about dark matter in cosmology is unwarranted because there has been no empirical confirmation of a dark matter particle. This demand is misguided. I argue that we should take the theoretical concept of dark matter as described in our best cosmological model (ΛCDM) at face value. Since there is no theoretical or nomological requirement that dark matter be a particle, we should better assess the implications of dark matter detection via gravitational lensing. The result is that realism about dark matter is a viable position. [ABSTRACT FROM AUTHOR]

The modified theories of gravity, especially the f(Q) theory, have attracted much attention in recent years. This study delves into non-static plane-symmetric solutions within the framework of this theory, employing a metric approach. The field equations are addressed with the incorporation of the Hubble parametrization H=H0 2 [1+(1+z)2(1+β)]1/2. The determination of optimal values for free parameters is achieved through the analysis of 57 data points of the Hubble parameter H(z). Additionally, the study explores the behavior of various cosmological parameters, including the deceleration parameter (q), energy density (ρ), pressure (p), and equation of state (EoS) parameter (ω), comparing them with observational findings. To validate the results, energy conditions and state finder analysis are undertaken. Ultimately, it is established that our model exhibits behavior akin to the ΛCDM model. Finally, we found that our model behaves similar to the ΛCDM model. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the anisotropic and spatially homogeneous Bianchi type-I universe with Kaniadakis holographic dark energy in Saez–Ballester [Phys. Lett. A 113, 467 (1986)] theory of gravitation. We determine Kaniadakis holographic dark energy model by assuming a correlation between the metric potentials to solve the field equations of the model. This results in a dynamical deceleration parameter which demonstrates an accelerating expansion of the universe. Our model's equation of state parameter ω khde close to − 1 (Λ CDM model) at late-times and is in agreement with the most recent observations. Next, we obtained the squared sound speed ( v s 2 ) and found that it is positive, implying stability against perturbations. The ω khde − ω khde ′ plane is constructed to investigate the evolution of the models' EoS parameter turned out to be in a freezing zone. As should be the case in an expanding universe, the strong energy conditions of the model are violated. Statefinders (r , s) , and r − q planes were also examined. Our model includes the Chaplygin gas, Λ CDM limit, and is inclined towards the steady-state model. [ABSTRACT FROM AUTHOR]

According to a number of astronomical studies, the universe is currently undergoing an accelerated expansion phase. We employed the recently proposed gravity, which holds that the current accelerated expansion phase of the universe is caused by a torsion scalar. The investigation is carried out using a parameterization of q (z) = − 1 + 3 2 ( (z + 1) q 2 q 1 + (z + 1) q 2 ) (where q 1 and q 2 are the model parameters) and the H (z) using H (z) = H 0 exp [ ∫ 0 z (1 + q (z)) d (ln (1 + z)) ] is obtained. The model shows good agreement with recent observations, such as the LCDM model at late times. Finally, we examined how the cosmological parameters behaved in for constrained values. [ABSTRACT FROM AUTHOR]

An analysis of the cosmological constant ΩΛ fitted to subsamples of the Pantheon+ Type Ia supernova sample spanning 2 π steradians for a grid of 432 pole positions covering the whole sky reveals two large-scale asymmetries. One of them is closely aligned with the Galactic north–south direction and the other points approximately toward R.A. ∼ 217.°5, decl. ∼ −26.°4, ∼50.°9 from the cosmic microwave background dipole Apex. The signal-to-noise ratio (S/N) of the multiple ΩΛ measurements in these directions is 3.2 ≲ S/N ≲ 8.4. The first asymmetry is puzzling, and would indicate a systematic effect related with the distribution of Pantheon+ supernovae on the sky and, probably, how the correction for reddening in the Galaxy is calculated. The second one, which entails a 2.8-σ tension between ΩΛ measured in opposite directions, bears strong implications on our interpretation of ΩΛ as dark energy: it is consistent with the prediction for tilted observers located in a Friedmann–Robertson–Walker universe who could measure an acceleration or a deceleration with a dipolar asymmetry, irrespective of what the universe as a whole is doing. In this case, ΩΛ would not be a physical entity, a real dark energy, but an apparent effect associated with the relativistic frame of reference transformation. [ABSTRACT FROM AUTHOR]

To investigate gravity in the nonlinear regime of cosmic structure using measurements from stage IV surveys, it is imperative to accurately compute large-scale structure observables, such as nonlinear matter power spectra, for gravity models that extend beyond general relativity. However, the theoretical predictions of nonlinear observables are typically derived from N -body simulations, which demand substantial computational resources. In this study, we introduce a novel public emulator, termed FREmu, designed to provide rapid and precise forecasts of nonlinear power spectra specifically for the Hu–Sawicki f (R) gravity model across scales 0.0089 h Mpc−1 < k < 0.5 h Mpc−1 and redshifts 0 < z < 3. FREmu leverages principal component analysis and artificial neural networks to establish a mapping from parameters to power spectra, utilizing training data derived from the Quijote-MG simulation suite. With a parameter space encompassing seven dimensions, including Ω m , Ω b , h, n s , σ 8, M ν , and f R 0 , the emulator achieves an accuracy exceeding 95% for the majority of cases, thus proving to be highly efficient for constraining parameters. [ABSTRACT FROM AUTHOR]

An analysis of the cosmological constant ΩΛ fitted to subsamples of the Pantheon+ Type Ia supernova sample spanning 2 π steradians for a grid of 432 pole positions covering the whole sky reveals two large-scale asymmetries. One of them is closely aligned with the Galactic north–south direction and the other points approximately toward R.A. ∼ 217.°5, decl. ∼ −26.°4, ∼50.°9 from the cosmic microwave background dipole Apex. The signal-to-noise ratio (S/N) of the multiple ΩΛ measurements in these directions is 3.2 ≲ S/N ≲ 8.4. The first asymmetry is puzzling, and would indicate a systematic effect related with the distribution of Pantheon+ supernovae on the sky and, probably, how the correction for reddening in the Galaxy is calculated. The second one, which entails a 2.8-σ tension between ΩΛ measured in opposite directions, bears strong implications on our interpretation of ΩΛ as dark energy: it is consistent with the prediction for tilted observers located in a Friedmann–Robertson–Walker universe who could measure an acceleration or a deceleration with a dipolar asymmetry, irrespective of what the universe as a whole is doing. In this case, ΩΛ would not be a physical entity, a real dark energy, but an apparent effect associated with the relativistic frame of reference transformation. [ABSTRACT FROM AUTHOR]

A new form of the mathematical expression for the co-moving volume element of a flat universe with cosmological constant, cold matter, and stiff matter is presented. It is used to determine the constraints from the Planck measurements of the Hubble parameter on the amount of stiff matter in the universe. These constraints are used to investigate whether the presence of stiff matter can solve the Hubble tension. It is found that the Planck measurements lead to an upper bound on the present value of the density parameter of stiff matter Ω S 0 < 5 ⋅ 10 − 23 , and that this is too small to solve the Hubble tension. Report. The main objective of this article is to introduce a novel mathematical expression for the co-moving volume element in a flat universe that includes a cosmological constant, cold matter, and stiff matter. This expression is utilized to derive constraints on the amount of stiff matter in the universe based on the Planck measurements of the Hubble parameter. These constraints are then examined to assess whether stiff matter could potentially resolve the Hubble tension. The findings indicate that the Planck measurements impose an upper limit on the current value of the density parameter of stiff matter, Ω S 0 < 5 ⋅ 10 − 23 , which is insufficient to resolve the Hubble tension. [ABSTRACT FROM AUTHOR]

At sufficiently large radii dark energy modifies the behavior of (a) bound orbits around a galaxy and (b) virialized gas in a cluster of galaxies. Dark energy also provides a natural cutoff to a cluster's dark matter halo. In (a) there exists a maximum circular orbit beyond which periodic motion is no longer possible, and orbital evolution near critical binding is analytically calculable using an adiabatic invariant integral. The finding implicates the study of wide galaxy pairs. In (b), dark energy necessitates the use of a generalized Virial Theorem to describe gas at the outskirts of a cluster. When coupled to the baryonic escape condition, aided by dark energy, the results is a radius beyond which the continued establishment of a hydrostatic halo of thermalized baryons is untenable. This leads to a theoretically motivated virial radius. We use this theory to probe the structure of a cluster's baryonic halo and apply it to X-ray and weak-lensing data collected on cluster Abell 1835. We find that gas in its outskirts deviates significantly from hydrostatic equilibrium beginning at ∼ 1.3 Mpc , the 'inner' virial radius. We also define a model dependent dark matter halo cutoff radius to A1835. The dark matter cutoff gives an upper limit to the cluster's total mass of ∼ 7 × 10 15 M ⊙ . Moreover, it is possible to derive an 'outer' hydrostatic equilibrium cutoff radius given a dark matter cutoff radius. A region of cluster gas transport and turbulence occurs between the inner and outer cutoff radii. [ABSTRACT FROM AUTHOR]

We investigate a coupled quintessence cosmological model in which a dark-energy scalar field with an exponential potential interacts directly with a dark-matter fluid through a dissipative term inspired by warm inflation. The evolution equations of this model give rise to a three-dimensional dynamical system for which a thorough qualitative analysis is performed for all values of the relevant parameters. We find that the model is able to replicate the observed sequence of late-time cosmological eras, namely, a long enough matter-dominated era followed by a present era of accelerated expansion. In situations where there is a significant transfer of energy from dark energy to dark matter, temporary scaling-type solutions may arise, but, asymptotically, all solutions are dominated by dark energy. [ABSTRACT FROM AUTHOR]

There are many arguments against the possibility of experimenting on the whole universe. This system seems to be too big to be manipulated, it exists in only one exemplar and its evolution is a non-repeatable process. In this paper, I claim that we can nonetheless talk about experimentation in cosmology if we use Woodward's non-anthropocentric notion of intervention. However, Woodward and other interventionists argued that an intervention was necessarily an exogenous causal process and thus that no intervention on a closed system such as the universe was possible. I discuss their argument and I determine the conditions under which a consistent notion of endogenous intervention on the universe can be defined. Then, I show that there is at least one cosmic phenomenon satisfying these conditions: the photon decoupling. Finally, I draw some conclusions from this analysis regarding a realist approach of cosmology. [ABSTRACT FROM AUTHOR]

Multiply lensed images of a same source experience a relative time delay in the arrival of photons due to the path length difference and the different gravitational potentials the photons travel through. This effect can be used to measure absolute distances and the Hubble constant ( H 0 ) and is known as time-delay cosmography. The method is independent of the local distance ladder and early-universe physics and provides a precise and competitive measurement of H 0 . With upcoming observatories, time-delay cosmography can provide a 1% precision measurement of H 0 and can decisively shed light on the current reported 'Hubble tension'. This manuscript details the general methodology developed over the past decades in time-delay cosmography, discusses recent advances and results, and, foremost, provides a foundation and outlook for the next decade in providing accurate and ever more precise measurements with increased sample size and improved observational techniques. [ABSTRACT FROM AUTHOR]

The doctrine of unity of opposites lays in the centre of the debate on Heraclitus' philosophy. The present article proposes a critical analysis of the mainstream interpretation of geometrical oppositions (fragments DK 22 B 59, B 60 and B 103) as mere examples of different points of view. Instead, we suggest that these fragments are fundamental pieces in Heraclitus cosmology and that they are traces of a circular and archaic paradigm. Indeed, cyclical formulations are spread throughout the fragments and, read in connection with geometrical oppositions, perform a useful model to describe how permanence and change can be complementary events. In this context, circularity can be a key to the comprehension of unity of opposites as a result of interchangeable processes – as day and night, life and death, beginning and end – so that opposites are part of a concrete and vital unity. [ABSTRACT FROM AUTHOR]

In the study of Saez–Ballester scalar tensor theory (Saez and Ballester in Phys Lett A 113:467, 1986), we examine the cosmic expansion phenomenon using the Rényi holographic dark energy (RHDE) with spatially homogeneous and anisotropic Marder type space time. Using a metric potential relationship, we find the solution to the field equations. Using Hubble and Granda–Oliveros horizon as IR cutoffs, we have derived the equation of state parameter (EoS) ( ω de ), RHDE energy density ( ρ de ) and matter energy density ( ρ m ), RHDE density parameter ( Ω de ), and Om-diagnostic. In this study, these parameters are plotted against the redshift (z). For three different choices of n and δ , the EoS parameter exhibits quintom-like behavior for both IR cutoffs. Further, looking into the ω de - ω de ′ plane and stability of the DE model by using a metric perturbation method. It has been found that quintom-like behavior and freezing region explain the Universe's accelerating rate of growth. [ABSTRACT FROM AUTHOR]

This paper deals with the physics of Anaximander and argues that, in his theory, the drying up of the sea cannot be accounted for in terms of the kind of conflict envisaged in his main fragment between the four basic substances: the hot, the cold, the wet and the dry (DK 12B1). In so doing, the paper takes issue with a classic interpretation of Anaximander's cosmology advocated by Jaap Mansfeld (2011). This issue also brings us to a wider philosophical problem: are meteorological phenomena in general amenable to this conflict according to Anaximander? In the conclusion, a few conjectural remarks are made regarding what may have been the real explanandum of this theory. [ABSTRACT FROM AUTHOR]

In this paper, we study the modifications induced on scalar field inflation produced by considering a general modification of the Heisenberg algebra. We proceed by modifying the Poisson brackets on the classical theory whenever the corresponding quantum commutator is modified. We do not restrict ourselves to a specific form for such modification, instead we constrain the functions involved by the cosmological behavior of interest. We present whenever possible the way in which inflation can be realized approximately via three slow roll Hubble parameters that depend on the standard slow roll parameters in a very different form than in the usual case and that can be less restrictive. Furthermore, we find a general analytical solution describing an expanding universe with constant Hubble parameter that generalizes the standard cosmological constant case by restricting the form of the modification of the Heisenberg algebra. It is found that even if such modification can be neglected in some limit and the cosmological constant is set to zero in that limit, the exponential expansion is present when the modification is important. Thus, an appropriate modification of the Heisenberg algebra is sufficient to produce an exponentially expanding universe without the need of any other source. [ABSTRACT FROM AUTHOR]

Void size function (VSF) contains the information of the cosmic large-scale structure (LSS), and can be used to derive the properties of dark energy and dark matter. We predict the VSFs measured from the spectroscopic galaxy survey operated by China's Space Survey Telescope (CSST), and study the strength of cosmological constraint. We employ a high-resolution Jiutian simulation to get CSST galaxy mock samples based on an improved semi-analytical model. We identify voids from this galaxy catalogue using the watershed algorithm without assuming a spherical shape, and estimate the VSFs at different redshift bins from |$z=0.5$| to 1.1. We propose a void selection method based on the ellipticity, and assume the void linear underdensity threshold |$\delta _{\rm v}$| in the theoretical model is redshift-dependent and set it as a free parameter in each redshift bin. The Markov Chain Monte Carlo method is adopted to implement the constraints on the cosmological and void parameters. We find that the CSST VSF measurement can constrain the cosmological parameters to a few per cent level. The best-fitting values of |$\delta _{\rm v}$| are ranging from |$\sim -0.4$| to |$-0.1$| as the redshift increases from 0.5 to 1.1, which has a distinct difference from the theoretical calculation with |$\delta _{\rm v}\simeq -2.7$| assuming the spherical evolution and using particles as tracer. Our method can provide a good reference for the void identification and selection in the VSF analysis of the spectroscopic galaxy surveys. [ABSTRACT FROM AUTHOR]

Inspired by high-energy physics and by considering standard gravity theory as the low-energy limit of quantum theory, the modification of general relativity as R + f (G) has been proposed. This paper is dedicated to investigating the cosmological model of modified Gauss–Bonnet gravity in four dimensions. General field equations for the four-dimensional Friedmann– Robertson–Walker metric are given in detail. Also, it is well known that Hubble parameter H (z) measurements are helpful for the inference of cosmological model parameters. We try to explain the MCMC statistical approach used to calculate Hubble's parameter. The resulting form of H (z) was limited using Cosmic Chronometric data, Standard Candles SN Ia from Pantheon, and Baryon Acoustic Oscillations to obtain the best match values by using the regression equation. Finally, to examine the late-time dynamics of our Universe, the behavior of physical and kinematic variables like the deceleration parameter (q) , State-finder parameters { r , s } , diagnostic parameter ( O m (z)), equation of state parameter as well as the behavior of energy conditions versus redshift with the parameter values are presented. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a U-Net model of deep learning algorithms for reconstructions of the 3D peculiar velocity field, which simplifies the reconstruction process with enhanced precision. We test the adaptability of the U-Net model with simulation data under more realistic conditions, including the redshift space distortion effect and halo mass threshold. Our results show that the U-Net model outperforms the analytical method that runs under ideal conditions, with a 16% improvement in precision, 13% in residuals, 18% in correlation coefficient, and 27% in average coherence. The deep learning algorithm exhibits exceptional capacities to capture velocity features in nonlinear regions and substantially improve reconstruction precision in boundary regions. We then apply the U-Net model trained under Sloan Digital Sky Survey (SDSS) observational conditions to the SDSS Data Release 7 data for observational 3D peculiar velocity reconstructions. [ABSTRACT FROM AUTHOR]

Observatories, experiments and techniques are being developed to spot ripples in space-time at frequencies that currently can't be detected. [ABSTRACT FROM AUTHOR]

We explore the impact of the chameleon mechanism in scalar field Einstein-Gauss-Bonnet gravity on the dynamics of cosmological parameters. Conducting a thorough analysis of the phase space, we identify conditions under which the future attractor does not depict a singular universe. Our conclusion is that although Einstein-Gauss-Bonnet scalar field gravity offers an inflationary solution as a future attractor, it is unable to account for the late-time acceleration of the universe and it can not describe a universe similar to that provide by the -CDM model. On the other hand, when the matter source is described by a massless scalar field, then the de Sitter universe is a future attractor. However, the hyperbolic inflationary solution provided by the two scalar fields does not exist. [ABSTRACT FROM AUTHOR]

This article explores the characteristics of interacting new Tsallis agegraphic dark energy (NTADE) and Sharma-Mittal holographic dark energy (SMHDE) models in a flat FLRWuniverse within Rastall gravity (RG). To check the viability of thesemodels and to distinguish them, we develop important cosmological parameters including equation of state (EoS) parameter, deceleration parameter q, square speed of sound, statefinder pair and Om(z) diagnostic. By constraining the different parameters for both dark energy (DE) models, it is observed that: EoS parameter indicates phantomlike behavior, deceleration parameter is showing a phase transition from decelerating to accelerating phase. The (j, s) plane is indicating a rich behavior as it shows different DE eras like quintessence, phantom and Chaplygin gas for both models depending upon interacting term d², parameter δ and Rastall parameter λ. The ωD - ω -- D pair is indicating freezing region for NTADE but for SMHDE it initially falls in freezing region then move towards thawing region. We also check stability of NTADE/SMHDE models through the graphical interpretation of square speed of sound. [ABSTRACT FROM AUTHOR]

We present SPICE , a new suite of radiation-hydrodynamic, cosmological simulations targeting the epoch of reionization. The goal of these simulations is to systematically probe a variety of stellar feedback models, including 'bursty' and 'smooth' forms of supernova energy injection, as well as poorly explored physical scenarios such as hypernova explosions and radiation pressure on dust. We show that even subtle differences in the behaviour of supernova feedback drive profound differences in reionization histories, with burstier forms of feedback causing earlier reionization. However, we also find that some global galaxy properties, such as the dust-attenuated luminosity functions and star formation main sequence, remain degenerate between models. In particular, we show that stellar feedback and its strength determine the morphological mix of galaxies emerging by |$z \, = \, 5$| and that the reionization history is inextricably connected to intrinsic properties such as galaxy kinematics and morphology. While star-forming, massive discs are prevalent if supernova feedback is 'smooth', 'bursty' feedback preferentially generates dispersion-dominated systems. Different modes of feedback produce different strengths of outflows, altering the interstellar/circumgalactic medium in different ways, and in turn strongly affecting the escape of Lyman continuum (LyC) photons. We establish a correlation between galaxy morphology and LyC escape fraction, revealing that dispersion-dominated systems have escape fractions 10–50 times higher than their rotation-dominated counterparts at all redshifts. At the same intrinsic luminosity, dispersion-dominated systems should thus preferentially generate large H  ii regions as compared to their rotation-dominated counterparts. Since dispersion-dominated systems are more prevalent if stellar feedback is more explosive, reionization occurs earlier in our simulation with burstier feedback. We argue that statistical samples of post-reionization galaxy morphologies (using both stellar and gaseous components) probed with telescopes such as JWST , ALMA, and MUSE can constrain stellar feedback at z > 5 and models of cosmic reionization. [ABSTRACT FROM AUTHOR]

In this review, a pedagogical introduction to the concepts of slow-roll inflationary universe and number of e-folds is provided. In particular, the differences between the basic notion of number of e-folds ( N e ), total number of e-folds ( N T ) and number of e-folds before the end of inflation (N) are outlined. The proper application of the number of e-folds before the end of inflation is discussed both as a time-like variable for the scalar field evolution and as a key parameter for computing inflationary predictions. [ABSTRACT FROM AUTHOR]

In this work, we discuss the de Sitter swampland conjectures in the context of the generalized Chaplygin-inspired inflationary model. We demonstrate that these conjectures can be satisfied, but only in the region of the parameter space far away from the General Relativity limit. The cosmic microwave background data had already been found to restrict the allowed inflationary potentials of this model. Our results impose a further limitation on the possible potentials. [ABSTRACT FROM AUTHOR]

Today's rich cosmological data sets require integration into a Biblical framework. The light-travel time issue is the most obvious difficulty involved, but it is by no means the only one. This article seeks to lay the groundwork for such integration by considering three Scripture passages: Hebrews 11:1-3; 2 Peter 3:5-7; and Romans 8:18-23. It notes that an accurate understanding of origins requires explicit inclusion of supraprovidential (i.e., miraculous) action, but that we should limit such action to what the Genesis record specifically warrants. It further suggests that in cosmology we can restrict this supraprovidential action to the Creation Week; that is, miraculous events connected with the Deluge did not affect the Universe as a whole. Finally, it suggests that there is no warrant for assuming that the physical effects of the Fall included changes in the actual laws of physics themselves. [ABSTRACT FROM AUTHOR]

Time-division multiplexing is the readout architecture of choice for many ground and space experiments, as it is a very mature technology with proven outstanding low-frequency noise stability, which represents a central challenge in multiplexing. Once fully populated, each of the two BICEP Array high-frequency receivers, observing at 150 GHz and 220/270 GHz, will have 7776 TES detectors tiled on the focal plane. The constraints set by these two receivers required a redesign of the warm readout electronics. The new version of the standard multichannel electronics, developed and built at the University of British Columbia, is presented here for the first time. BICEP Array operates time-division multiplexing readout technology to the limits of its capabilities in terms of multiplexing rate, noise and cross talk, and applies them in rigorously demanding scientific application requiring extreme noise performance and systematic error control. Future experiments like CMB-S4 plan to use TES bolometers with time-division/SQUID-based readout for an even larger number of detectors. [ABSTRACT FROM AUTHOR]

In this study, we analyze Type Ia supernovae (SNe Ia) data sourced from the Pantheon+ compilation to investigate late‐time physics effects influencing the expansion history, H(z)$$ H(z) $$, at redshifts (z<2)$$ \left(z<2\right) $$. Our focus centers on a time‐varying dark energy (DE) model that introduces a rapid transition in the equation of state, at a specific redshift, za$$ {z}_a $$, from the baseline, wΛ=−1$$ {w}_{\Lambda}=-1 $$, value to the present value, w0$$ {w}_0 $$. The change in the equation of state is implemented as a transition in the DE density scale factor driven by a sigmoid function. The constraints obtained for the DE sigmoid phenomenological parametrization have broad applicability for dynamic DE models that invoke late‐time physics. Our analysis indicates that the sigmoid model provides a slightly better, though not statistically significant, fit to the SNe Pantheon+ data compared to the standard Λ$$ \Lambda $$ cold dark matter (ΛCDM$$ \Lambda \mathrm{CDM} $$) model. The fit results, assuming a flat geometry and maintaining Ωm$$ {\Omega}_m $$ constant at the 2018‐Planck value of 0.3153$$ 0.3153 $$, are as follows: H0=73.3−0.6+0.2$$ {H}_0={73.3}_{-0.6}^{+0.2} $$ km s −1$$ {}^{-1} $$ Mpc −1$$ {}^{-1} $$, w0=−0.95−0.02+0.15$$ {w}_0=-{0.95}_{-0.02}^{+0.15} $$, za=0.8±0.46$$ {z}_a=0.8\pm 0.46 $$. The errors represent statistical uncertainties only. The available SN dataset lacks sufficient statistical power to distinguish between the baseline ΛCDM$$ \Lambda \mathrm{CDM} $$ model and the alternative sigmoid models. A feature of interest offered by the sigmoid model is that it identifies a specific redshift, za=0.8$$ {z}_a=0.8 $$, where a potential transition in the equation of state could have occurred. The sigmoid model does not favor a DE in the phantom region (w0<−1$$ {w}_0<-1 $$). Further constraints to the dynamic DE model have been obtained using CMB data to compute the distance to the last scattering surface. While the sigmoid DE model does not completely resolve the H0$$ {H}_0 $$ tension, it offers a transition mechanism that can still play a role alongside other potential solutions. [ABSTRACT FROM AUTHOR]

Music is an integral part of culture and human societies, which anthropologists study. What makes music so potent is its ability to contain values, reflect perspectives, and fill niches of societal needs. In this paper, I will discuss how ethnomusicology aids scholars in a deeper understanding of contexts, perspectives, and values in music and the experiences of the people who created it. I will analyze the relationships between music and technique, ritual, and religion in seven case studies. Drawing from examples from "right" singing in Estonia, the choral works of Stravinsky, Ambonwari rituals, ritual wailing in Amerindian Brazil, the maqam, syncretism in Southeast Asia, and Tamil Christian religious music, I will show how ethnomusicology uncovers understanding of the cosmology, values, and socio-cultural interactions of a people and their culture. [ABSTRACT FROM AUTHOR]

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In this work, we have analyzed Bianchi type-I space-time (spatially homogeneous and anisotropic), using an interacting two fluid - dark matter (DM) and Pilgrim dark energy (PDE) in the framework of f(T) gravity by taking into consideration the infrared (IR) cut-off as a candidate of Hubble’s horizon L=1/H. We have also performed the state-finder diagnostics and in addition, energy conditions are discussed to verify accelerating expansion of the universe.

End-to-end simulations play a key role in the analysis of any high-sensitivity cosmic microwave background (CMB) experiment, providing high-fidelity systematic error propagation capabilities that are unmatched by any other means. In this paper, we address an important issue regarding such simulations, namely, how to define the inputs in terms of sky model and instrument parameters. These may either be taken as a constrained realization derived from the data or as a random realization independent from the data. We refer to these as posterior and prior simulations, respectively. We show that the two options lead to significantly different correlation structures, as prior simulations (contrary to posterior simulations) effectively include cosmic variance, but they exclude realization-specific correlations from non-linear degeneracies. Consequently, they quantify fundamentally different types of uncertainties. We argue that as a result, they also have different and complementary scientific uses, even if this dichotomy is not absolute. In particular, posterior simulations are in general more convenient for parameter estimation studies, while prior simulations are generally more convenient for model testing. Before BEYONDPLANCK, most pipelines used a mix of constrained and random inputs and applied the same hybrid simulations for all applications, even though the statistical justification for this is not always evident. BEYONDPLANCK represents the first end-to-end CMB simulation framework that is able to generate both types of simulations and these new capabilities have brought this topic to the forefront. The BEYONDPLANCK posterior simulations and their uses are described extensively in a suite of companion papers. In this work, we consider one important applications of the corresponding prior simulations, namely, code validation. Specifically, we generated a set of one-year LFI 30 GHz prior simulations with known inputs and we used these to validate the core low-level BEYONDPLANCK algorithms dealing with gain estimation, correlated noise estimation, and mapmaking.

Dark matter research, aimed at unraveling astrophysical enigmas, faces the challenge of lacking concrete evidence connecting dark matter with the observable universe in both experimental and theoretical particle physics. Our study investigates a simplified extension to the Standard Model (SM) where SM fermion interacts with a hypothetical vector dark matter (DM) particle in high-energy collisions, mediated by a proposed massive spin-1 particle, Z ′ . We specifically explore vector DM pair production through fermion annihilation in this mediator, focusing on a near-resonance condition ( m χ ∼ M Z ′ / 2 ). This includes examining monophoton production, a SM signal, as a result of initial-state radiation. We also calibrate the coupling constants between DM and SM particles relative to Planck satellite thermal relic density data, particularly near a resonance where traditional models anticipate more relic density suppression. Our findings, consistent with expected relic density at resonance regimes, suggest mass ranges and coupling constants for these DM particles that align with collider and astrophysical limits, to be validated in CLIC and LHC settings. [ABSTRACT FROM AUTHOR]

Superluminous supernovae (SLSNe) are a class of intense celestial events that can be standardized for measuring cosmological parameters, bridging the gap between type Ia supernovae and the cosmic microwave background. In this work, we discuss the cosmological applications of SLSNe from the Chinese Space Station Telescope (CSST). Our estimation suggests that SLSNe rate is biased tracing the cosmic star formation rate, exhibiting a factor of (1 + z)1.2. We futher predict that CSST is poised to observe ∼ 360 SLSNe in the 10 square degrees ultra-deep field survey within a span of 2.5 years. A stringent constraint on cosmological parameters can be derived from their peak-color relationship. CSST is anticipated to uncover a substantial number of SLSNe, contributing to a deeper understanding of their central engines and shedding light on the nature of dark energy at high redshifts. [ABSTRACT FROM AUTHOR]