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Related papers: Dark Energy in an Astrophysical Context

200 papers

The dark matter in or around the cosmic voids affects their shapes. The thermodynamical properties of dark matter can alter the ellipticity of cosmic voids. Here, applying the dark matter equation of state from the pseudo-isothermal density…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-08 Zeinab Rezaei

Hamilton et al. have suggested an invaluable scaling formula which describes how the power spectra of density fluctuations evolve into the nonlinear regime of hierarchical clustering. This paper presents an extension of their method to…

Astrophysics · Physics 2016-06-08 J. A. Peacock , S. J. Dodds

Newton's law gets modified in the presence of a cosmological constant by a small repulsive term (antigarvity) that is proportional to the distance. Assuming a value of the cosmological constant consistent with the recent SnIa data ($\Lambda…

Astrophysics · Physics 2014-10-13 M. Axenides , E. G. Floratos , L. Perivolaropoulos

Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by incorporating `dark energy', of which the…

Astrophysics · Physics 2010-03-26 Luke Barnes , Matthew J. Francis , Geraint F. Lewis , Eric V. Linder

The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-13 Shulei Cao

We show that the presence of a temporal electromagnetic field on cosmological scales generates an effective cosmological constant which can account for the accelerated expansion of the universe. Primordial electromagnetic quantum…

Astrophysics · Physics 2011-07-13 Jose Beltran Jimenez , Antonio L. Maroto

We study the cosmological consequences of a recently proposed nonlocal modification of general relativity, obtained by adding a term $m^2R\,\Box^{-2}R$ to the Einstein-Hilbert action. The model has the same number of parameters as…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-16 Yves Dirian , Stefano Foffa , Nima Khosravi , Martin Kunz , Michele Maggiore

We study non-linear structure formation in the presence of dark energy. The influence of dark energy on the growth of large-scale cosmological structures is exerted both through its background effect on the expansion rate, and through its…

Astrophysics · Physics 2008-11-26 L. R. Abramo , R. C. Batista , L. Liberato , R. Rosenfeld

We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…

General Physics · Physics 2019-03-13 V. G. Gurzadyan , A. Stepanian

The Schr\"odinger-Newton equation is a proposed model to explain the localization of macroscopic particles by suppressing quantum dispersion with the particle's own gravitational attraction. On cosmic scales, however, dark energy also acts…

General Relativity and Quantum Cosmology · Physics 2020-04-01 Kelvin , Kelvin Onggadinata , Matthew J. Lake , Tomasz Paterek

Dark energy has a dramatic effect on the dynamics of the universe, causing the recently discovered acceleration of the expansion. The dynamics are also central to the behavior of the growth of large scale structure, offering the possibility…

Astrophysics · Physics 2009-11-07 Eric V. Linder , Adrian Jenkins

It was recently suggested that the cosmological constant problem as viewed in a non-perturbative framework is intimately connected to the choice of time and a physical Hamiltonian. We develop this idea further by calculating the…

General Relativity and Quantum Cosmology · Physics 2018-04-05 Syed Moeez Hassan

High precision cosmological observations in last decade suggest that about 70% of our universe's energy density is in so called "Dark Energy" (DE). Observations show that DE has negative effective pressure and therefore unlike conventional…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 Lado Samushia

We assume the cosmological dark sector to consist of pressureless matter and holographic dark energy with a cutoff length proportional to the Ricci scale. The requirement of separate energy-momentum conservation of the components is shown…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sergio del Campo , Júlio. C. Fabris , Ramón Herrera , Winfried Zimdahl

In this letter we study the effects of a noncommutative in the phase space of an empty (4+1) Kaluza-Klein universe with cosmological constant. We analyze the effects of the noncommutative deformations on the cosmological constant. Finally…

High Energy Physics - Theory · Physics 2013-07-09 E. Mena , S. Pérez-Payán , M. Sabido

In this work, we consider the effect of the cosmological constant on galactic halo size. As a model, we study the general relativistic derivation of orbits in the Schwarzschild-de Sitter metric. We find that there exists a length scale…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Ekapob Kulchoakrungsun , Adrian Lam , David A. Lowe

One of the fundamental assumptions of the standard $\Lambda$CDM cosmology is that, on large scales, all the matter-energy components of the Universe share a common rest frame. This seems natural for the visible sector, that has been in…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 J. A. R. Cembranos , A. L. Maroto , H. Villarrubia-Rojo

Current cosmological data indicate that our universe contains a substantial component of dark vacuum energy that is driving the cosmos to accelerate. We examine the immediate and longer term consequences of this dark energy (assumed here to…

Astrophysics · Physics 2010-12-09 Michael T. Busha , Fred C. Adams , Risa H. Wechsler , August E. Evrard

We investigate the influence of dark energy on structure formation, within five different cosmological models, namely a concordance $\Lambda$CDM model, two models with dynamical dark energy, viewed as a quintessence scalar field (using a RP…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Cristiano De Boni , Klaus Dolag , Stefano Ettori , Lauro Moscardini , Valeria Pettorino , Carlo Baccigalupi

The high-quality cosmological data, which became available in the last decade, have thrusted upon us a rather preposterous composition for the universe which poses one of the greatest challenges theoretical physics has ever faced: the…

Astrophysics · Physics 2015-06-24 J. S. Alcaniz