Observational constraints on Rastall's cosmology

Abstract

Rastall's theory is a modification of General Relativity, based on the non-conservation of the stress-energy tensor. The latter is encoded in a parameter $\gamma$ such that $\gamma =1$ restores the usual ${\nabla }_{\nu }{T}^{\mu \nu }=0$ law. We test Rastall's theory in cosmology, on a flat Robertson-Walker metric, investigating a two-fluid model and using the type Ia supernovae Constitution dataset. One of the fluids is pressureless and obeys the usual conservation law, whereas the other is described by an equation of state $p_x=w_x{\rho }_x$, with $w_x$ constant. The Bayesian analysis of the Constitution set does not strictly constrain the parameter $\gamma$ and prefers values of $w_x$ close to -1. We then address the evolution of small perturbations and show that they are dramatically unstable if $w_x\ne -1$ and $\gamma \ne 1$, i.e. General Relativity is the favored configuration. The only alternative is $w_x=-1$, for which the dynamics becomes independent from $\gamma$.

Latex file, 14 pages, 6 figures in eps format. Substantial modifications performed, main conclusions changed

References in corpus (6)

• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Bulk Viscous Cosmology
• Gauge-invariant analysis of perturbations in Chaplygin gas unified models of dark matter and dark energy
• Rastall cosmology
• Does Chaplygin gas have salvation?
• Six Puzzles for LCDM Cosmology

Cited by in corpus (37)

• Black Hole Solutions Surrounded by Perfect Fluid in Rastall Theory
• A Generalization to the Rastall Theory and Cosmic Eras
• Accelerated cosmos in a non-extensive setup
• Thermodynamics of flat FLRW universe in Rastall Theory
• Complexity and Isotropization based Extended Models in the context of Electromagnetic Field: An Implication of Minimal Gravitational Decoupling
• Thermodynamic analysis of the static spherically symmetric field equations in Rastall theory
• Einstein Static Universe in Rastall Theory of Gravity
• Rastall gravity extension of the standard $\Lambda$CDM model: theoretical features and observational constraints
• Cosmological consequences in the framework of generalized Rastall theory of gravity
• Shadows of black hole surrounded by anisotropic fluid in Rastall theory
• Wormhole Solutions in Rastall Gravity Theory
• A connection between Rastall-type and f(R, T) gravities
• Thin-shell wormholes in Rastall gravity
• Neutral regular black hole solution in generalized Rastall gravity
• Linear growth index of matter perturbations in Rastall gravity
• Qualitative study of anisotropic Rastall cosmologies
• The criteria of the anisotropic quark star models in Rastall gravity
• Cosmic evolution of dark energy in a generalized Rastall gravity
• Abelian-Higgs strings in Rastall gravity
• The Einstein dark energy model
• Higher dimensional power-Maxwell charged black holes in Einstein and Rastall gravity
• A thermodynamics revision of Rastall gravity
• Compact stars in Rastall gravity: hydrostatic equilibrium and radial pulsations
• Rapidly rotating compact stars in Rastall's gravity
• On Gödel-type Solution in Rastall's Gravity
• A dynamical system representation of generalized Rastall gravity
• Observational Constraints on the Rastall gravity from Rotation Curves of Low Surface Brightness Galaxies
• Null Fluid collapse in Rastall theory of gravity
• Effects of Rastall parameter on perturbation of dark sectors of the Universe
• Qusinormal oscillations and late-time tail of massless scalar perturbations of a magnetized black hole in Rastall gravity
• Non-Singular Collapse Scenario From Matter-Curvature Coupling
• Thermodynamic features of AdS black holes within the Rastall gravity and perfect fluid matter framework
• Charged analog of anisotropic dark energy star in Rastall gravity
• Primordial Black Hole Formation in Rastall Gravity: Shifted Collapse Threshold and Exponential Abundance Sensitivity
• Matter perturbations in Einstein dark energy model
• Neutrino Interactions with perturbed Rastall Gravity: A Novel Approach to Reducing the Hubble Tension
• Singularity Avoidance in Gravitational Collapse of an Inhomogeneous Fluid in Rastall Gravity