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Related papers: Cosmological Tests for a Linear Coasting Cosmology

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A strictly linear evolution of the cosmological expansion scale factor is a characteristic feature in several classes of alternative gravity theories as also in the standard (big-bang) model with specially chosen equations of state of…

Astrophysics · Physics 2009-10-31 Abha Dev , Meetu Sethi , Daksh Lohiya

A strictly linear evolution of the cosmological scale factor is surprisingly an excellent fit to a host of cosmological observations. Any model that can support such a coasting presents itself as a falsifiable model as far as classical…

Astrophysics · Physics 2007-05-23 Savita Gehlaut , Pranav Kumar , Geetanjali , Daksh Lohiya

A strictly linear evolution of the cosmological scale factor is surprisingly an excellent fit to a host of cosmological observations. Any model that can support such a coasting presents itself as a falsifiable model as far as classical…

Astrophysics · Physics 2007-05-23 Savita Gehlaut , A. Mukherjee , S. Mahajan , D. Lohiya

Linearly coasting cosmology is comfortably concordant with a host of cosmological observations. It is surprisingly an excellent fit to SNe Ia observations and constraints arising from age of old quasars. In this article we highlight the…

Astrophysics · Physics 2011-07-19 Geetanjali Sethi , Abha Dev , Deepak Jain

The standard model of cosmology ($\Lambda$CDM) is facing a serious crisis caused by the inconsistencies in the measurements of some fundamental cosmological parameters (Hubble constant $H_{0}$ and cosmic curvature parameter $\Omega_{k}$ for…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Savita Gahlaut

Instead of assuming a form of gravity and demand cosmology fit with $\Lambda CDM$, a potentially `viable' $f(R)$ gravity model is derived assuming an alternative model of cosmology. Taking the `designer' approach to $f(R)$, a new class of…

General Relativity and Quantum Cosmology · Physics 2018-01-16 Rohin Kumar

Recent developments in gravitational lensing astronomy have paved the way to genuine mappings of the gravitational potential at cosmological scales. We stress that comparing these data with traditional large scale structure surveys will…

High Energy Physics - Phenomenology · Physics 2009-10-31 Jean-Philippe Uzan , Francis Bernardeau

The effect of a time dependent cosmological constant is considered in a family of scalar tensor theories. Friedmann-Robertson-Walker cosmological models for vacumm and perfect fluid matter are found. They have a linear expansion factor, the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Luis O. Pimentel , L. M. Diaz-Rivera

Cosmological observations are beginning to reach a level of precision that allow us to test some of the most fundamental assumptions in our working model of the Universe. One such an assumption is that gravity is governed by the General…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 Pedro G. Ferreira

An attempt is made here to extend to the microscopic domain the scale invariant character of gravitation - which amounts to consider expansion as applying to any physical scale. Surprisingly, this hypothesis does not prevent the redshift…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Pierre Midy , Jean-Pierre Petit

General relativity as one the pillar of modern cosmology has to be thoroughly tested if we want to achieve an accurate cosmology. We present the results from such a test on cosmological scales using cosmic shear and galaxy clustering…

In a bid to resolve lingering problems in cosmology, more focus is being tilted towards cosmological models in which physical constants of nature are not necessarily real constants but vary with cosmic time. In this paper, we study a…

General Relativity and Quantum Cosmology · Physics 2022-05-05 Gabriel W. Joseph , Ali Övgün

Using the linear theory of perturbations in General Relativity, we express a set of consistency relations that can be observationally tested with current and future large scale structure surveys. We then outline a stringent…

Astrophysics · Physics 2009-11-13 Yong-Seon Song , Olivier Doré

In view of new experimental results that strongly suggest a non-zero cosmological constant, it becomes interesting to revisit the Friedman-Lemaitre model of evolution of a universe with cosmological constant and radiation pressure. In this…

Astrophysics · Physics 2007-05-23 Robert Coquereaux , Alex Grossmann

Recent observations of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a `cosmological constant', which acts to accelerate the expansion rate with time. But these data by themselves still…

Astrophysics · Physics 2009-10-31 Idit Zehavi , Avishai Dekel

Modifications to gravity can provide attractive alternatives to the dark components of the standard model of cosmology. These modifications to general relativity (GR) must be hidden at small scales where theory is well tested, and so one…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-06 Benjamin Bose

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

A power law cosmology is defined by the cosmological scale factor evolving as $t^{\alpha}$. In this work, we put bounds on $\alpha$ by using the joint test of the SNe Ia data from Supernova Legacy Survey (SNLS) and H(z) data with curvature…

Astrophysics · Physics 2008-04-23 Abha Dev , Deepak Jain , Daksh Lohiya

A linear evolution of the cosmological scale factor is a feature in several models designed to solve the cosmological constant problem via a coupling between scalar or tensor classical fields to the space-time curvature as well as in some…

Astrophysics · Physics 2009-11-07 Deepak Jain , Abha Dev , J. S. Alcaniz

The bouncing evolution of an universe in Loop Quantum Cosmolgy can be described very well by a set of effective equations, involving a function $sin \; x$. Recently, we have generalised these effective equations to $(d + 1)$ dimensions and…

General Relativity and Quantum Cosmology · Physics 2017-08-02 S. Kalyana Rama
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