Recognition: unknown
Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
read the original abstract
We study a class of metric-variation f(R) models that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the parameter space. Solar-system tests alone place only weak bounds on these models, since the additional scalar degree of freedom is locked to the high-curvature general-relativistic prediction across more than 25 orders of magnitude in density, out through the solar corona. This agreement requires that the galactic halo be of sufficient extent to maintain the galaxy at high curvature in the presence of the low-curvature cosmological background. If the galactic halo and local environment in f(R) models do not have substantially deeper potentials than expected in LCDM, then cosmological field amplitudes |f_R| > 10^{-6} will cause the galactic interior to evolve to low curvature during the acceleration epoch. Viability of large-deviation models therefore rests on the structure and evolution of the galactic halo, requiring cosmological simulations of f(R) models, and not directly on solar-system tests. Even small deviations that conservatively satisfy both galactic and solar-system constraints can still be tested by future, percent-level measurements of the linear power spectrum, while they remain undetectable to cosmological-distance measures. Although we illustrate these effects in a specific class of models, the requirements on f(R) are phrased in a nearly model-independent manner.
This paper has not been read by Pith yet.
Forward citations
Cited by 7 Pith papers
-
Late-time reconstruction of non-minimally coupled gravity with a smoothness prior
Non-parametric reconstruction of non-minimally coupled gravity with a smoothness prior on CMB, DESI BAO, supernovae, and DES data yields a 2.8σ hint for coupling and a preference for phantom divide crossing stabilized...
-
A Master Equation for Screening in Luminal Horndeski Gravity
A master screening equation is derived for luminal Horndeski gravity that recovers Vainshtein and Chameleon mechanisms and introduces Phaedrus screening with screening radius scaling linearly with source mass.
-
Studying spherical collapse and its implications in the Eddington-inspired Born-Infeld gravity theory
In EiBI gravity, spherical collapse yields lower linear thresholds, higher turnaround and virial overdensities, and modestly smaller turnaround radii than in ΛCDM, with effects increasing with the coupling κ̂_BI.
-
Unveiling $f(R)$ Gravity with Void-Galaxy Cross-Correlation Multipoles
Void-galaxy cross-correlation multipoles exhibit amplified size-dependent deviations from LCDM in f(R) gravity due to the scalaron fifth force and nonlinear shell dynamics, providing a new probe for modified gravity.
-
Studying spherical collapse and its implications in the Eddington-inspired Born-Infeld gravity theory
In EiBI gravity, spherical collapse needs regularized density profiles to handle singular gradient terms, yielding a lower linear collapse threshold, higher turnaround and virial overdensities, and slightly smaller tu...
-
Testing Scale-Dependent Modified Gravity with DESI DR1
DESI DR1 constrains the modified gravity parameter to log10 |f_R0| < -4.59 at 95% CL, implying no detectable fifth force on scales below about 18 Mpc.
-
Extended Dark Energy analysis using DESI DR2 BAO measurements
Extended analysis of DESI DR2 data confirms robust evidence for dynamical dark energy with phantom crossing preference, stable under parametric and non-parametric modeling.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.