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Related papers: Accelerated expansion from cosmological holography

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The Hubble constant $H_0$, the current expansion rate of the universe, is one of the most important parameters in cosmology. The cosmic expansion regulates the mutually approaching motion of a pair of celestial objects due to their gravity.…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-30 Wangzheng Zhang , Ming-chung Chu , Shihong Liao , Shek Yeung , Hui-Jie Hu

By incorporating the holographic principle in a time-depending Lambda-term cosmology, new physical bounds on the arbitrary parameters of the model can be obtained. Considering then the dark energy as a purely geometric entity, for which no…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. P. Beltran Almeida , J. G. Pereira

Holographic model is originated from Holographic principle. The equation of state in Holographic model and Einstein's gravity with particle horizon can be obtained as wD>-1/3 and cannot justify the expansion acceleration of the Universe.…

General Relativity and Quantum Cosmology · Physics 2017-06-27 Ehsan Sadri

Four Hubble diagrams are combined to test for the linearity of the cosmic expansion field. The expansion rate, H_0, is found to decrease by ~5% out to 18000km/s. Beyond this distance the mean value of H_0 is close to the value at 10000km/s.…

Astrophysics · Physics 2007-05-23 G. A. Tammann

Observations reveal a `bulk flow' in the local Universe which is faster and extends to much larger scales than is expected around a typical observer in the standard $\Lambda$CDM cosmology. This is expected to result in a scale-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 Jacques Colin , Roya Mohayaee , Mohamed Rameez , Subir Sarkar

The presence of the dark energy allows both the acceleration and the expansion of the universe. In the case of a constant equation of state for dark energy we derived an analytical solution for the Hubble radius in terms of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-06 Lorenzo Zaninetti

Landauer's principle and the Holographic principle are used to derive the holographic information energy contribution to the Universe. Information energy density has increased with star formation until sufficient to start accelerating the…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-24 Michael Paul Gough

It has been demonstrated that a modern stage of the Universe expansion may be described in accordance with the observations within the scope of the space-time conformal geometry. The clock synchronization procedure in SR has been…

General Relativity and Quantum Cosmology · Physics 2010-01-21 L. M. Tomilchik , N. G. Kembrovskaya

In this paper, we show that the expansion history of the Universe in power-law cosmology essentially depends on two crucial parameters, namely the Hubble constant $H_{0}$ and deceleration parameter $q$. We find the constraints on these…

General Relativity and Quantum Cosmology · Physics 2014-08-27 Suresh Kumar

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

In this work, we propose a new model that combines holographic dark energy with modified gravity $f(Q,T)$ to explore a possible explanation for the accelerated expansion of the universe. Since there are several tensions of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-08 Xuwei Zhang , Xiaofeng Yang , Yunliang Ren , Shuangnan Chen , Yangjun Shi , Cheng Cheng , Xiaolong He

We consider the holographic dark energy model with axial torsion which satisfy the cosmological principle. Subsequently, by using the torsional analogues of Friedmann equations for the new equation from Einstein-Cartan gravity theory, we…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Yongjun Yun , Jungjai Lee

Galaxy dynamics probes weak gravity at accelerations below the de Sitter scale of acceleration $a_{dS}=cH$, where $c$ is the velocity of light and $H$ is the Hubble parameter. Low and high redshift galaxies hereby offer a novel probe of…

Astrophysics of Galaxies · Physics 2017-10-18 Maurice H. P. M. van Putten

Motivated by the observed cosmic matter distribution, we present the following conjecture: due to the formation of voids and opaque structures, the average matter density on the path of the light from the well-observed objects changes from…

Astrophysics · Physics 2010-02-23 Teppo Mattsson

Recent observations of high redshift Supernovae at lower than expected value of the Hubble constant, widely interpreted as an evidence for accelerating expansion of the Universe, could alternatively be explained assuming a hyperbolic…

Astrophysics · Physics 2007-05-23 Mikolaj "Mik" Sawicki

We measure the current expansion rate of the Universe, Hubble's constant $H_0$, by calibrating the absolute magnitudes of supernovae to distances measured by Baryon Acoustic Oscillations. This `inverse distance ladder' technique provides an…

The observed luminosity deficit of Type Ia supernovae (SNe Ia) at high redshift z can be explained by partial conversion to weak vector bosons of photons crossing large-scale electroweak domain boundaries, making Hubble acceleration only…

Astrophysics · Physics 2008-11-26 Tommy Anderberg

Recent measurements of type Ia supernovae as well as other concordant observations suggest that the expansion of our universe is accelerating. A dark energy component has usually been invoked as the most feasible mechanism for the…

Astrophysics · Physics 2014-10-13 Zong-Hong Zhu , Masa-Katsu Fujimoto , Xiang-Tao He

In this work, we study a cosmological model of spatially homogeneous and isotropic accelerating universe which exhibits a transition from deceleration to acceleration. For this, Friedmann Robertson Walker(FRW) metric is taken and Hybrid…

General Relativity and Quantum Cosmology · Physics 2021-08-02 G. K. Goswami , Anirudh Pradhan , Meena Mishra , A. Beesham

Our cosmology contains Big Bang relic fluctuations by a loss of time-translation symmetry on a Hubble time scale. The contribution to the vacuum is identified with dynamical dark energy $\Lambda\simeq \alpha_p\Lambda_0$ by an IR coupling…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-26 Maurice H. P. M. van Putten