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Friedmann–Lemaître–Robertson–Walker metric

About: Friedmann–Lemaître–Robertson–Walker metric is a research topic. Over the lifetime, 4113 publications have been published within this topic receiving 87752 citations. The topic is also known as: FLRW metric.


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Journal ArticleDOI
TL;DR: In this paper, the governing equations for multiple scalar fields in a flat Friedmann-Robertson-Walker (FRW) background spacetime on all scales, allowing for metric and field perturbations up to second order, were given.
Abstract: We give the governing equations for multiple scalar fields in a flat Friedmann–Robertson–Walker (FRW) background spacetime on all scales, allowing for metric and field perturbations up to second order. We then derive the Klein–Gordon equation at second order in closed form in terms of gauge-invariant perturbations of the fields in the uniform curvature gauge. We also give a simplified form of the Klein–Gordon equation using the slow-roll approximation.

61 citations

Journal ArticleDOI
TL;DR: In this article, the authors considered a non-trivial test of the new gravity theory in FRW universe by considering an IR modification which breaks ''softly'' the detailed balance condition in the original Hoava model.
Abstract: Recently Ho?ava proposed a renormalizable gravity theory with higher spatial derivatives in four dimensions which reduces to Einstein gravity with a non-vanishing cosmological constant in IR but with improved UV behaviors. Here, I consider a non-trivial test of the new gravity theory in FRW universe by considering an IR modification which breaks ``softly'' the detailed balance condition in the original Ho?ava model. I separate the dark energy parts from the usual Einstein gravity parts in the Friedman equations and obtain the formula of the equations of state parameter. The IR modified Ho?ava gravity seems to be consistent with the current observational data but we need some more refined data sets to see whether the theory is really consistent with our universe. From the consistency of our theory, I obtain some constraints on the allowed values of w0 and wa in the Chevallier, Polarski, and Linder's parametrization and this may be tested in the near future, by sharpening the data sets.

61 citations

Journal ArticleDOI
TL;DR: In this paper, the cosmological evolution of a homogeneous and isotropic brane with a scalar field nonminimally coupled to the induced Ricci curvature is studied.
Abstract: We present the four-dimensional equations on a brane with a scalar field nonminimally coupled to the induced Ricci curvature, embedded in a five-dimensional bulk with a cosmological constant. This is a natural extension to a brane-world context of scalar-tensor (Brans-Dicke) gravity. In particular we consider the cosmological evolution of a homogeneous and isotropic (FRW) brane. We identify low-energy and strong-coupling limits in which we recover effectively four-dimensional evolution. We find de Sitter brane solutions with both constant and evolving scalar field. We also consider the special case of a conformally coupled scalar field for which it is possible (when the conformal energy density exactly cancels the effect of the bulk black hole) to recover a conventional four-dimensional Friedmann equation for all energy densities.

61 citations

Journal ArticleDOI
TL;DR: In this article, the cosmological features of Tsallis holographic dark energy (THDE) in cyclic, DGP and RS II braneworlds were studied.

61 citations

Journal ArticleDOI
TL;DR: In this article, an extended Chaplygin gas equation of state for which it recovers barotropic fluid with quadratic EO of state was proposed, where numerical method was used to investigate the behavior of some cosmological parameters such as scale factor, Hubble expansion parameter, energy density, and deceleration parameter.
Abstract: We propose extended Chaplygin gas equation of state for which it recovers barotropic fluid with quadratic equation of state. We use numerical method to investigate the behavior of some cosmological parameters such as scale factor, Hubble expansion parameter, energy density, and deceleration parameter. We also discuss the resulting effective equation of state parameter. Using density perturbations we investigate the stability of the theory.

61 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023150
2022352
2021196
2020204
2019214
2018191