Observational constraints on nonlinear matter extensions of general relativity: Separable trace power models

Abstract

The search for the physical mechanism underlying the observational evidence for the acceleration of the recent universe is a compelling goal of modern fundamental cosmology. Here we quantitatively study a class of homogeneous and isotropic cosmological models in which the matter side of Einstein's equations includes, in addition to the canonical term, a term proportional to the trace of the energy-momentum tensor, $T=\rho -3p$, and constrain these models using low redshift background cosmology data. One may think of these models as extensions of general relativity with a nonlinear matter Lagrangian, and they can be studied either as phenomenological extensions of the standard $\Lambda$CDM model, containing both matter and a cosmological constant, or as direct alternatives to it, where there is no cosmological constant but the additional terms would have to be responsible for accelerating the universe. Overall, our main finding is that parametric extensions of $\Lambda$CDM are tightly constrained, with additional model parameters being constrained to their canonical behaviours to within one standard deviation, while alternative models in this class (which do not have a $\Lambda$CDM limit) are ruled out. This provides some insight on the level of robustness of the $\Lambda$CDM model and on the parameter space still available for phenomenological alternatives and extensions.

arXiv comment14 pages, 4 figures, 4 tables; Physics of the Dark Universe (in press). Some particular results were previously reported in a conference proceedings at arXiv:2201.00591

References in corpus (23)

• Dynamics of dark energy
• Modified Gravity and Cosmology
• f(R,T) gravity
• Dark Energy and the Accelerating Universe
• Conditions for the cosmological viability of f(R) dark energy models
• Age-dating Luminous Red Galaxies observed with the Southern African Large Telescope
• Are f(R) dark energy models cosmologically viable ?
• Cardassian Expansion: a Model in which the Universe is Flat, Matter Dominated, and Accelerating
• Hubble parameter measurement constraints on the redshift of the deceleration-acceleration transition, dynamical dark energy, and space curvature
• Dynamics of scalar perturbations in f(R,T) gravity
• Type Ia Supernova Distances at z > 1.5 from the Hubble Space Telescope Multi-Cycle Treasury Programs: The Early Expansion Rate
• Energy-Momentum Squared Gravity
• $f(R,T_{\mu \nu }{T}^{\mu \nu })$ gravity and Cardassian-like expansion as one of its consequences
• The Cardassian expansion revisited: constraints from updated Hubble parameter measurements and Type Ia Supernovae data
• Cosmological Models in Energy-Momentum-Squared Gravity
• Cosmological inviability of $f(R,T)$ gravity
• Cosmic acceleration in dust only Universe via energy-momentum powered gravity
• Problems with Time-Varying Extra Dimensions or "Cardassian Expansion" as Alternatives to Dark Energy
• Low redshift constraints on energy-momentum-powered gravity models
• Impact of young stellar components on quiescent galaxies: deconstructing cosmic chronometers
• Estimation of Cosmological Parameters, Stability Analysis and Energy Conditions in Viable Modified Gravity
• Dark sectors of the Universe: A Euclid survey approach
• On the robustness of the H$\beta$ Lick index as a cosmic clock in passive early-type galaxies

Cited by in corpus (3)

• Evolution of Spherical Overdensities in Energy-Momentum-Squared Gravity
• Quadratic energy-momentum squared gravity: constraints from big bang nucleosynthesis
• Weak field and slow motion limits in energy-momentum powered gravity