$\gamma$ gravity: Steepness control

Abstract

We investigate a simple generalization of the metric exponential $f(R)$ gravity theory that is cosmologically viable and compatible with solar system tests of gravity. We show that, as compared to other viable $f(R)$ theories, its steep dependence on the Ricci scalar $R$ facilitates agreement with structure constraints, opening the possibility of $f(R)$ models with equation-of-state parameter that could be differentiated from a cosmological constant ($w_{de}=-1$) with future surveys at both background and perturbative levels.

v3: matches the version accepted by PRD

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• f(R) theories
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Cited by in corpus (8)

• Generalised Ellis-Bronnikov Wormholes in $f(R)$ Gravity
• Gravitational wave propagation in $f(R)$ models: New parametrizations and observational constraints
• Extrasolar planets as a probe of modified gravity
• Calculation of the critical overdensity in the spherical-collapse approximation
• Cosmological constraints on $\gamma$-gravity models
• Classical and quantum $f(R)$ cosmology: The big rip, the little rip and the little sibling of the big rip
• N-body Simulations of $\gamma$ Gravity
• Thermodynamics of $f(R)$ Theories of Gravity