We calculate static and spherically symmetric solutions for the Rastall modification of gravity to describe neutron stars (NS). The key feature is nonconservation energy-momentum tensor proportionally space-time curvature. Using realistic equations state NS interior we place a conservative bound on non-general relativity behavior theory which should be $\ensuremath{\lesssim}1%$ level. This work presents more stringent constraints deviations general caused by proposal.

Since there is no known symmetry in Nature that prevents a non-minimal coupling between the dark energy (DE) and cold matter (CDM) components, such possibility constitutes an alternative to standard cosmology, with its theoretical observational consequences being of great interest. In this paper we propose new null test on evolution sector based time dependence ratio CDM DE densities which, $\Lambda$CDM scenario, scales necessarily as $a^{-3}$. We use latest measurements type Ia supernovae,...

ABSTRACT Next-generation surveys will provide photometric and spectroscopic data of millions to billions galaxies with unprecedented precision. This offers a unique chance improve our understanding the galaxy evolution unresolved nature dark matter (DM). At scales, density distribution DM is strongly affected by feedback processes, which are difficult fully account for in classical techniques derive masses. We explore capability supervised machine learning (ML) algorithms predict content...

Early-type galaxies (ETGs) are reference systems to understand galaxy formation and evolution processes. The physics of their collapse internal dynamics codified in well-known scaling relations. Cosmological hydrodynamical simulations play an important role, providing insights into the 3D distribution matter mechanisms, as well validating methods infer properties real objects. In this work, we present closest-to-reality sample ETGs from IllustrisTNG100-1 simulation, dubbed "virtual-ETGs,"...

Abstract Early-type galaxies (ETGs) are reference systems to understand galaxy formation and evolution processes. The physics of their internal dynamics codified in well-known scaling relations. In this context, cosmological hydrodynamical simulations play an important role probing the physical origins relations by providing a controlled environment study galaxies, linking underlying processes, testing robustness observational inference methods. work, we present closest-to-reality sample...

The possibility of dark matter being a dissipative component represents an option for the standard view where cold (CDM) particles behave on large scales as ideal fluid. By including physical mechanism in description like viscosity, we construct more realistic model Universe. Also, known small scale pathologies CDM either disappear or become less severe. We study clustering properties $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$-like which is described bulk viscous linear power spectrum,...

Relaxing the conventional assumption of a minimal coupling between dark matter (DM) and energy (DE) fields introduces significant changes in predicted evolution Universe. Therefore, testing such possibility constitutes an essential task not only for cosmology but also fundamental physics. In previous communication [Phys. Rev. D99, 043521, 2019], we proposed new null test $\Lambda$CDM model based on time dependence ratio DM DE densities which is able to detect potential signatures interaction...

Accurate predictions on non--linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information Dark Energy nature. This calls for high precision simulations, covering the whole functional space of w(z) state equations and taking also into account admitted ranges other parameters; surely difficult task. A procedure was however suggested, able match spectra z=0, up k~3, hMpc^{-1}, in cosmologies with...

We present the Dark MaGICC (Making Galaxies in a Cosmological Context) project, which aims to investigate effect of dark energy (DE) modelling on disc galaxy formation via hydrodynamical cosmological simulations. includes four dynamical DE scenarios with time varying equations state, one self-interacting Ratra–Peebles model. In each scenario, we simulate three galaxies high resolution using smoothed particle hydrodynamics. The baryonic physics model is same used and varied only background...

Effects of velocity dispersion dark matter particles on the CMB TT power spectrum and linear are investigated using a modified CAMB code. Cold originated from thermal equilibrium processes does not produce appreciable effects but this is case if have non-thermal origin. A cut-off in at small scales, similar to that produced by warm or late forming scenario, appears as consequence effects, which act pressure perturbation.

Abstract Local measurements of the Hubble constant ( $$H_0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>H</mml:mi> <mml:mn>0</mml:mn> </mml:msub> </mml:math> ) based on Cepheids e Type Ia supernova differ by $$\approx 5 \sigma $$ <mml:mrow> <mml:mo>≈</mml:mo> <mml:mn>5</mml:mn> <mml:mi>σ</mml:mi> </mml:mrow> from estimated value Planck CMB observations under $$\Lambda <mml:mi>Λ</mml:mi> CDM assumptions. In order to better understand this tension, comparison...

Forthcoming experiments will enable us to determine tomographic shear spectra at a high precision level. Most predictions about them have until now been biased on algorithms yielding the expected linear and non-linear spectrum of density fluctuations. Even when simulations used, so-called Halofit (Smith et al 2003) fairly large scales needed. We wish go beyond this limitation. perform N-body hydrodynamical within sufficiently cosmological volume allow direct connection between spectra. While...

An interaction between dark matter and energy, proportional to the product of their energy densities, results in a scaling behavior ratio these densities with respect scale factor Robertson-Walker metric. This gives rise class cosmological models which deviate from standard model an analytically tractable way. In particular, it becomes possible quantify role potential dark-energy perturbations. We investigate impact this on structure formation process. Using (modified) CAMB code we obtain...

The next generation mass probes will obtain information on non--linear power spectra P(k,z) and their evolution, allowing us to investigate the nature of Dark Energy. To exploit such data we need high precision simulations, extending at least up scales k 10 h/Mpc, where effects baryons can no longer be neglected. In this paper, present a series large scale hydrodynamical simulations for LCDM dynamical Energy (dDE) models, in which equation state parameter is z-dependent. include gas cooling,...

We investigate the impact of non-linear corrections on dark energy parameter estimation from weak lensing probes. find that using halofit expressions, suited to ΛCDM models, implies substantial discrepancies with respect results directly obtained N-body simulations, when w(z)≠−1. Discrepancies appear strong models w'(z = 0) > 0, as fiducial models; they are however significant even in neighborhood ΛCDM, where neglecting degrees freedom associated DE state equation can lead a misestimate...

We discuss an extension of the Coyote emulator to predict non-linear matter power spectra dark energy (DE) models with a scale factor dependent equation state form w = w_0 + ( 1 - )w_a . The is based on mapping rule between DE constant and those time varying one originally introduced in ref. [40]. Using series N-body simulations we show that spectral equivalence accurate sub-percent level across same range modes redshift covered by suite. Thus, extended provides very efficient tool for w_a...

In this work we discuss observational aspects of three time-dependent parameterisations the dark energy equation state $w(z)$. order to determine dynamics associated with these models, calculate their background evolution and perturbations in a scalar field representation. After performing complete treatment linear perturbations, also show that non-linear contribution selected $w(z)$ matter power spectra is almost same for all scales, no significant difference from predictions standard...

We present the first numerical simulations in coupled dark energy cosmologies with high enough resolution to investigate effects of coupling on galactic and sub-galactic scales. choose two constant couplings a time-varying function we run three Milky-Way-size halos ($\sim$10$^{12}$M$_{\odot}$), lower mass halo (6$\times$10$^{11}$M$_{\odot}$) dwarf galaxy (5$\times$10$^{9}$M$_{\odot}$). resolve each several millions matter particles. On all scales causes concentrations reduced number...