The present universe in the Einstein frame, metric-affine R+1/R gravity

Abstract

We study the present, flat isotropic universe in 1/R-modified gravity. We use the Palatini (metric-affine) variational principle and the Einstein (metric-compatible connected) conformal frame. We show that the energy density scaling deviates from the usual scaling for nonrelativistic matter, and the largest deviation occurs in the present epoch. We find that the current deceleration parameter derived from the apparent matter density parameter is consistent with observations. There is also a small overlap between the predicted and observed values for the redshift derivative of the deceleration parameter. The predicted redshift of the deceleration-to-acceleration transition agrees with that in the Λ-CDM model but it is larger than the value estimated from SNIa observations.

11 pages; published version

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Cited by in corpus (15)

• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• Limit to General Relativity in f(R) theories of gravity
• Matter instability in modified gravity
• de Sitter space and the equivalence between f(R) and scalar-tensor gravity
• Locally Rotationally Symmetric Bianchi Type $I$ Cosmology in $f(R,T)$ Gravity
• A viability criterion for modified gravity with an extra force
• Violation of the Equivalence Principle in Modified Theories of Gravity
• Bianchi Type-$V$ cosmology in $f(R,T)$ gravity with $\Lambda (T)$
• The phase space view of f(R) gravity
• Interacting dark energy in $f(R)$ gravity
• The Cauchy problem of f(R) gravity
• The cosmic snap parameter in f(R) gravity
• The cosmic jerk parameter in f(R) gravity
• Equilibrium hydrostatic equation and Newtonian limit of the singular f(R) gravity
• F(R) gravity in purely affine formulation