Results 31 to 40 of about 540,486 (189)
Non-linear Evolution of Matter Power Spectrum in Modified Theory of Gravity [PDF]
, 2009 We present a formalism to calculate the non-linear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy.
Atsushi Taruya +5 more
core +3 more sources
THERMODYNAMICS IN MODIFIED GRAVITY THEORIES [PDF]
International Journal of Modern Physics D, 2011 We demonstrate that there exists an equilibrium description of thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density f(R,ϕ,X), where R is the Ricci scalar and X is the kinetic energy of a scalar field ϕ.
Bamba, Kazuharu +2 more
openaire +2 more sources
Exact rotating black hole solutions for f(R) gravity by modified Newman Janis algorithm
European Physical Journal C: Particles and Fields, 2023 We show that the f(R)-gravity theories with constant Ricci scalar in the Jordan/Einstein frame can be described by Einstein or Einstein–Maxwell gravity with a cosmological term and a modified gravitational constant.
Pankaj Chaturvedi +3 more
doaj +1 more source
Reissner–Nordström Anti-de Sitter Black Holes in Mimetic F(R) Gravity
Universe, 2016 In this paper, we study under which conditions the Reissner–Nordström anti-de Sitter black hole can be a solution of the vacuum mimetic F ( R ) gravity with Lagrange multiplier and mimetic scalar potential.
V. K. Oikonomou
doaj +1 more source
Constraining Modified Gravity with Euclid [PDF]
, 2010 Future proposed satellite missions as Euclid can offer the opportunity to test general relativity on cosmic scales through mapping of the galaxy weak lensing signal. In this paper we forecast the ability of these experiments to constrain modified gravity
A. R. Cooray +8 more
core +2 more sources
The P-V phase transition of the FRW universe
European Physical Journal C: Particles and Fields, 2022 We define thermodynamic pressure P by work density W as the conjugate quantity of thermodynamic volume V from field equation. We derive the equations of state P=P(V, T) for the Friedmann–Robertson–Walker (FRW) universe in Einstein gravity and a modified ...
Shi-Bei Kong +4 more
doaj +1 more source
Modified gravity: A unified approach [PDF]
Physical Review D, 2021 Starting from the original Einstein action, sometimes called the Gamma squared action, we propose a new setup to formulate modified theories of gravity. This can yield a theory with second order field equations similar to those found in other popular modified gravity models. Using a more general setting the theory gives fourth order equations.
Christian G. Böhmer, Erik Jensko
openaire +3 more sources
Rastall gravity is equivalent to Einstein gravity
Physics Letters B, 2018 Rastall gravity, originally developed in 1972, is currently undergoing a significant surge in popularity. Rastall gravity purports to be a modified theory of gravity, with a non-conserved stress–energy tensor, and an unusual non-minimal coupling between ...
Matt Visser
doaj +1 more source
Chaos in a Magnetized Modified Gravity Schwarzschild Spacetime
Universe, 2022 Based on the scalar–tensor–vector modified gravitational theory, a modified gravity Schwarzschild black hole solution has been given in the existing literature.
Daqi Yang +5 more
doaj +1 more source
Off-Diagonal Deformations of Kerr Black Holes in Einstein and Modified Massive Gravity and Higher Dimensions [PDF]
, 2013 We find general parameterizations for generic off-diagonal spacetime metrics and matter sources in general relativity (GR) and modified gravity theories when the field equations decouple with respect to certain types of nonholonomic frames of reference ...
Gheorghiu, Tamara +2 more
core +3 more sources