Reexamining $f(R,T)$ gravity

Abstract

We study $f(R,T)$ gravity, in which the curvature $R$ appearing in the gravitational Lagrangian is replaced by an arbitrary function of the curvature and the trace $T$ of the stress-energy tensor. We focus primarily on situations where $f$ is separable, so that $f(R,T)=f_1(R)+f_2(T)$. We argue that the term $f_2(T)$ should be included in the matter Lagrangian ${\mathcal{L}}_m$, and therefore has no physical significance. We demonstrate explicitly how this can be done for the cases of free fields and for perfect fluids. We argue that all uses of $f_2(T)$ for cosmological modeling and all attempts to place limits on parameters describing $f_2(T)$ are misguided.

References in corpus (11)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• f(R,T) gravity
• Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications
• Dark Energy and the Accelerating Universe
• Action functionals for relativistic perfect fluids
• Dark Matter From f(R,T) Gravity
• Stellar equilibrium configurations of white dwarfs in the $f(R,T)$ gravity
• Strange stars in $f(R,\mathcal{T})$ gravity
• Cosmological inviability of $f(R,T)$ gravity
• Limits on $f(R,T)$ Gravity from Earth's Atmosphere

Cited by in corpus (42)

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• To conserve, or not to conserve: A review of nonconservative theories of gravity
• Charged quark stars in $f(R,T)$ gravity
• General approach to the Lagrangian ambiguity in $f(R,T)$ gravity
• The Reconstruction of Constant Jerk Parameter with $f(R,T)$ Gravity
• Slow-roll inflation in $f(R,T)$ gravity with a $RT$ mixing term
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• Reconstruction of an Observationally Constrained $f(R,T)$ gravity model
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• Fully conservative $f(R,T)$ gravity and Solar System constraints
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• CFT Duals on Rotating Charged Black Holes Surrounded by Quintessence
• Rotating black holes and exotic compact objects in the Kerr/CFT correspondence within Rastall gravity
• Are $f(R,\mathrm{Matter})$ theories really relevant to cosmology?
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• Perturbation Spectra of Warm Inflation in $f(Q,T)$ Gravity
• Nuclear Limits on Non-Minimally Coupled Gravity
• Effect of bulk viscosity in cosmic acceleration
• Consistent energy-momentum trace couplings of fluids
• NEC violation in $f(\bar{R},\bar{T})$ gravity in the context of a non-canonical theory via modified Raychaudhuri equation
• Thermodynamics of a Non-canonical $f(\bar{R},\bar{T})$ gravity
• Cosmological dynamics of interacting dark energy and dark matter in $f(Q)$ gravity
• Gravitation with modified fluid Lagrangian: Variational principle and an early dark energy model
• Modified $f(R,T)$ theory in light of gravitational wave standard sirens
• Comparison of $f(R,T)$ Gravity with Type Ia Supernovae Data
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• Intermediate Coupling Regime in Dilatonic $f(R,T)$ Inflationary Universe
• Inflation and primordial fluctuations in $f(Q,T)$ gravity
• Bayesian and Machine-Learning Analyses of Nonminimal $f(Q)$ Gravity and $H_0$ Tension
• Lagrangian Identity and Mass Evolution of Particle-like Objects in Nonminimally Coupled Gravity
• Dynamics of quasi de Sitter and linear combination of exponential models in extended gravity
• Exploration of Parameters in f(R,T) Gravity and Comparison with Type Ia Supernovae Data