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相关论文: On cosmic acceleration without dark energy

200 篇论文

In this work, I develop an alternative explanation for the acceleration of the cosmic expansion, which seems to be a result of recent high redshift Supernova data. In the current interpretation, this cosmic acceleration is explained by…

广义相对论与量子宇宙学 · 物理学 2007-05-23 J. -F. Pascual-Sánchez

We discuss the effect of super-Hubble cosmological fluctuations on the locally measured Hubble expansion rate. We consider a large bare cosmological constant in the early universe in the presence of scalar field matter (the dominant matter…

高能物理 - 理论 · 物理学 2018-11-28 Robert Brandenberger , Leila L. Graef , Giovanni Marozzi , Gian Paolo Vacca

The dissipation of energy from local velocity perturbations in the cosmological fluid affects the time evolution of spatially averaged fluid dynamic fields and the cosmological solution of Einstein's field equations. We show how this…

广义相对论与量子宇宙学 · 物理学 2015-03-11 Stefan Floerchinger , Nikolaos Tetradis , Urs Achim Wiedemann

In relativistic cosmology, the formation of nonlinear inhomogeneities can induce non-negligible backreaction on late-time expansion. Among the important consequences for precision cosmology is the potential impact on the linear growth of…

广义相对论与量子宇宙学 · 物理学 2026-04-27 Marco Galoppo , Pierre Mourier

We show that by allowing our Universe to merge with other universes one is lead to modified Friedmann equations that explain the present accelerated expansion of our Universe without the need of a cosmological constant.

广义相对论与量子宇宙学 · 物理学 2023-08-23 Jan Ambjorn , Yoshiyuki Watabiki

The problem of cosmic acceleration and dark energy is one of the mysteries presently posed in the scientific society that general relativity has not been able to solve. In this work, we have considered alternative models to explain this…

广义相对论与量子宇宙学 · 物理学 2022-12-01 M. Koussour , N. Myrzakulov , S. H. Shekh , M. Bennai

A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic…

天体物理学 · 物理学 2008-11-26 Michael S. Turner , Dragan Huterer

We present here a general relativistic mechanism for accelerated cosmic expansion and the Hubble's constant. It is shown that spacetime vorticity coupled to the magnetic field density in galaxies causes the galaxies to recede from one…

宇宙学与河外天体物理 · 物理学 2019-03-20 Babur M. Mirza

In this paper we give a physical explanation to the accelerated expansion of the Universe, alleviating the tension between the discrepancy of Hubble constant measurements. By the Euler Cauchy stress principle, we identify a controversy on…

广义相对论与量子宇宙学 · 物理学 2021-02-17 C. Ortiz

We investigate whether an accelerating universe can be realized as an asymptotic late-time solution of FLRW-cosmology with multi-field multi-exponential potentials. Late-time cosmological solutions exhibit a universal behavior which enables…

高能物理 - 理论 · 物理学 2023-09-25 Gary Shiu , Flavio Tonioni , Hung V. Tran

Recently, new arguments (astro-ph/0501152, hep-th/0503117) for how corrections from super-Hubble modes can explain the present-day acceleration of the universe have appeared in the literature. However, in this letter, we argue that, to…

天体物理学 · 物理学 2009-11-10 Ghazal Geshnizjani , Daniel J. H. Chung , Niayesh Afshordi

Recent surveys seem to support bulk peculiar velocities well in excess of those anticipated by the standard cosmological model. In view of these results, we consider here some of the theoretical implications of large-scale drift motions. We…

宇宙学与河外天体物理 · 物理学 2015-05-13 Christos G Tsagas

Since its decovery during the late 90's, the dimming of distant SN Ia apparent luminosity has been mostly ascribed to the influence of a mysterious dark energy component. Based upon the cosmological "principle" hypothesis, this…

天体物理学 · 物理学 2016-11-15 Marie-Noëlle Célérier

In this paper we present an alternative explanation to the acceleration of the universe and the dark energy problems in terms of the Friedmann Thermodynamics. This model has the capability of making definite predictions in-line with the…

天体物理学 · 物理学 2007-05-23 Selcuk Bayin

If general relativity (GR) describes the expansion of the Universe, the observed cosmic acceleration implies the existence of a `dark energy'. However, while the Universe is on average homogeneous on large scales, it is inhomogeneous on…

天体物理学 · 物理学 2008-11-26 Aseem Paranjape , T. P. Singh

We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are allowed to be highly non-linear, and the…

广义相对论与量子宇宙学 · 物理学 2017-02-24 Viraj A. A. Sanghai , Timothy Clifton

In `entropic cosmology', instead of a cosmological constant $\Lambda$, an extra driving term is added to the Friedmann equation and the acceleration equation, taking into account the entropy and the temperature on the horizon of the…

宇宙学与河外天体物理 · 物理学 2013-03-14 Nobuyoshi Komatsu , Shigeo Kimura

Understanding the evolution of dark energy poses a significant challenge in modern cosmology, as it is responsible for the universe's accelerated expansion. In this study, we focus on a specific $f(T)$ cosmological model and analyze its…

宇宙学与河外天体物理 · 物理学 2024-05-14 A. Zhadyranova , M. Koussour , S. Bekkhozhayev , V. Zhumabekova , J. Rayimbaev

We show that the current accelerated expansion of the Universe can be explained without resorting to dark energy. Models of generalized modified gravity, with inverse powers of the curvature can have late time accelerating attractors…

天体物理学 · 物理学 2008-11-26 Olga Mena , Jose Santiago , Jochen Weller

It has recently been shown that the observed Hubble function for cosmological expansion can be fitted accurately back to redshift unity (7.33 Gyr ago) with only one free constant, while neglecting cosmic curvature and mass, using the…

综合物理 · 物理学 2021-05-26 R. K. Nesbet