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Motivated by the dawn of precision cosmology and the wealth of forthcoming high precision and volume galaxy surveys, in this paper we study the effects of inhomogeneities on light propagation in a flat \Lambda CDM background. To this end we…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Nikolai Meures , Marco Bruni

Dark energy may be the first sign of new fundamental physics in the Universe, taking either a physical form or revealing a correction to Einsteinian gravity. Weak gravitational lensing and galaxy peculiar velocities provide complementary…

The plethora of recent cosmologically relevant data has indicated that our universe is very well fit by a standard Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) model, with $\Omega_{M} \approx 0.27$ and $\Omega_{\Lambda} \approx 0.73$ --…

Astrophysics · Physics 2009-06-23 M. E. Araújo , W. R. Stoeger

Background cosmological dynamics for a universe with matter, a scalar field non-minimally derivative coupling to Einstein tensor under power-law potential and holographic vacuum energy is considered here. The holographic IR cutoff scale is…

General Relativity and Quantum Cosmology · Physics 2024-06-17 Amornthep Tita , Burin Gumjudpai , Pornrad Srisawad

In this paper, cosmic distance duality relation is probed without considering any background cosmological model. The only \textit{a priori} assumption is that the Universe is described by the Friedmann-Lema$\hat{i}$tre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2025-01-28 Savita Gahlaut

We find that an observer with a suitable acceleration relative to the frame comoving whit the cosmic fluid, in the context of the FRW decelerating universe, measures the same cosmological redshift as the LambdaCDM model. The estimated value…

General Relativity and Quantum Cosmology · Physics 2017-08-29 Antonio Feoli , Elmo Benedetto

The current cosmological paradigm sees the formation and evolution of the cosmic large-scale structure as governed by the gravitational attraction of the Dark Matter (DM) and the repulsion of the Dark Energy (DE). We characterize the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 P. Teerikorpi , P. Heinämäki , P. Nurmi , A. D. Chernin , M. Einasto , M. Valtonen , G. Byrd

Dark energy is a premier mystery of physics, both theoretical and experimental. As we look to develop plans for high energy physics over the next decade, within a two decade view, we consider benchmarks for revealing the nature of dark…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-12 Eric V. Linder

The expansion rate of the Universe changes with time, initially slowing (decelerating) when the universe was matter dominated, because of the mutual gravitational attraction of all the matter in it, and more recently speeding up…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-17 Muhammad Omer Farooq

We use the recent type Ia supernova, cosmic microwave background and large-scale structure data to shed light on the temporal evolution of the dark energy equation of state $w(z)$ out to redshift one. We constrain the most flexible…

Astrophysics · Physics 2008-11-26 Gong-Bo Zhao , Dragan Huterer , Xinmin Zhang

Determination of the expansion and acceleration history of the universe is one of the fundamental goals of cosmology. Detailed measurements of these rates as a function of redshift can provide new physical insights into the nature and…

Astrophysics · Physics 2009-11-07 Ruth A. Daly , S. G. Djorgovski

The coming decade will be an exciting period for dark energy research, during which astronomers will address the question of what drives the accelerated cosmic expansion as first revealed by type Ia supernova (SN) distances, and confirmed…

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the…

Inspired by the well-studied $\Lambda_{\rm s}$CDM model, we propose and investigate a class of dynamical dark energy models that evolve from a negative cosmological constant, transitioning to a positive value at low redshifts. Specifically,…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Mariam Bouhmadi-López , Beñat Ibarra-Uriondo

The explanation of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. If the acceleration is driven by some form of dark energy, one can try to constrain the parameters…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Marek Demianski , Ester Piedipalumbo , Claudio Rubano , Paolo Scudellaro

We investigate the properties of the FLRW flat cosmological models in which the vacuum energy density evolves with time, $\Lambda(t)$. Using different versions of the $\Lambda(t)$ model, namely quantum field vacuum, power series vacuum and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Basilakos , M. Plionis , J. Sola

The standard LambdaCDM model of cosmology is usually understood to arise from demanding that the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric satisfy the General Relativity dynamics for spacetime metrics. The FLRW data-based dominant…

General Physics · Physics 2009-07-13 Reginald T Cahill

We use data from observational cosmology to put constraints on higher-dimensional extensions of general relativity in which the effective four-dimensional dark-energy density (or cosmological "constant") decays with time. In particular we…

Astrophysics · Physics 2009-11-13 J. M. Overduin , P. S. Wesson , B. Mashhoon

In theoretical physics, the fundamental nature and evolution mechanism of dark energy is still an open question. In General Relativity Theory, the simplest explanation for dark energy is the cosmological constant $\Lambda$. However, the…

General Relativity and Quantum Cosmology · Physics 2022-03-09 Raja Solanki , Avik De , P. K. Sahoo

In this work we consider a flat cosmological model with a set of fluids in the framework of supersymmetric cosmology. The obtained supersymmetric algebra allowed us to take quantum solutions. It is shown that only in the case of a…

General Relativity and Quantum Cosmology · Physics 2010-12-23 J. J. Rosales , V. I. Tkach