English
Related papers

Related papers: Comments on an alternative theory for the accelera…

200 papers

In recent years, there has been a growing interest in stellar modelling in the framework of Einstein-Gauss-Bonnet gravity. In this paper, for a relativistic star in static equilibrium, we invoke the $5$ dimensional Einstein-Gauss-Bonnet…

General Relativity and Quantum Cosmology · Physics 2023-06-22 Soumik Bhattacharya , Suntharalingam Thirukkanesh , Ranjan Sharma

New precision in measuring extragalactic distances using supernovae has confirmed with high probability an accelerating increase in redshift with distance. This has been interpreted as implying the existence of dark energy in an expanding…

Astrophysics · Physics 2007-05-23 William Q. Sumner

It is shown that using the relativistic field theory of gravity (RTG) and measured value of $\Omega_{tot}$ one can obtain the upper limit on the graviton mass with 95%C.L.: $m\leq 1.6\cdot 10^{-66}$ [g]; within the $(1\sigma)$ range its…

Astrophysics · Physics 2009-04-28 S. S. Gershtein , A. A. Logunov , M. A. Mestvirishvili , N. P. Tkachenko

The existence of current-time universe's acceleration is usually modeled by means of two main strategies. The first makes use of a dark energy barotropic fluid entering \emph{by hand} the energy-momentum tensor of Einstein's theory. The…

General Relativity and Quantum Cosmology · Physics 2015-07-24 Orlando Luongo , Hernando Quevedo

We propose that the existence of the string landscape suggests the universe can be in a quantum glass state, where an extremely large viscosity is generated, and long distance dynamics slows down. At the same time, the short distance…

High Energy Physics - Theory · Physics 2010-10-27 Jian-Huang She

We use Wetterich's parameterization equation of state (EOS) of dark energy to a $5D$ Ricci-flat cosmological solution and we suppose the universe contains three major components: matter, radiation and dark energy. By using the relation…

Astrophysics · Physics 2009-11-11 Chengwu Zhang , Hongya Liu , Lixin Xu , P. S. Wesson

Peculiar velocities are an important probe of the growth rate of mass density fluctuations in the Universe. Most previous studies have focussed exclusively on measuring peculiar velocities at intermediate ($0.2 < z < 1$) redshifts using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Michael J. Hudson , Stephen J. Turnbull

We introduce the curvature $\Omega_k$ as a new free parameter in the Bayesian analysis using SNIa, BAO and CMB data, in a model with variable equation of state parameter $w(z)$. We compare the results using both the Constitution and Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Victor H. Cardenas , Marco Rivera

Recent astronomical observations indicate that the Universe is presently almost flat and undergoing a period of accelerated expansion. Basing on Einstein's general relativity all these observations can be explained by the hypothesis of a…

Astrophysics · Physics 2007-06-13 Marek Szydlowski , Aleksandra Kurek , Adam Krawiec

A model for the universe with both acceleration and deceleration is given. The model incorporates an initial acceleration, then a deceleration as has been observed by Schaefer in respect of gamma ray bursts, a second phase of acceleration…

Astrophysics · Physics 2007-05-23 Nalin de Silva

We develop a pipeline to set new constraints on scale-independent modified gravity, from the galaxy power spectrum in redshift space of BOSS DR12. The latter is modelled using the effective field theory of large-scale structure up to 1-loop…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Lorenzo Piga , Marco Marinucci , Guido D'Amico , Massimo Pietroni , Filippo Vernizzi , Bill S. Wright

A brief review of main features of the new approach named ``quantum geometrodynamics in extended phase space'' is given and its possible prospects are discussed. Gauge degrees of freedom are treated as a subsystem of the Universe which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Shestakova

The self-accelerating braneworld model (DGP) seems to provide a simple alternative to the the standard $\Lambda$CDM cosmology to explain the current cosmic acceleration, which is strongly indicated by measurements of Type Ia supernovae, as…

Astrophysics · Physics 2009-11-13 Zong-Hong Zhu , Mauro Sereno

Current observations of Type Ia supernovae provide evidence for cosmic acceleration out to a redshift of $z \lsim 1$, leading to the possibility that the universe is entering an inflationary epoch. However, inflation can take place only if…

Astrophysics · Physics 2009-10-31 Glenn Starkman , Mark Trodden , Tanmay Vachaspati

In this letter we investigate some consequences of considering our 4D observable universe as locally and isometrically embeded into a 5D spacetime, where gravity is described by a Brans-Dicke theory in vacuum. Once we impose the embeding…

General Relativity and Quantum Cosmology · Physics 2017-06-28 José Edgar Madriz Aguilar , J. Zamarripa , A. Peraza , J. A. Licea

It is nowadays accepted that the universe is undergoing a phase of accelerated expansion as tested by the Hubble diagram of Type Ia Supernovae (SNeIa) and several LSS observations. Future SNeIa surveys and other probes will make it possible…

Astrophysics · Physics 2009-02-20 S. Capozziello , V. F. Cardone , V. Salzano

We investigate late time acceleration of the universe in higher dimensional cosmology. The content in the universe is assumed to exert pressure which is different in the normal and extra dimensions. Cosmologically viable solutions are found…

General Relativity and Quantum Cosmology · Physics 2011-09-29 Isha Pahwa , Debajyoti Choudhury , T. R. Seshadri

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

We find exact solutions in five dimensional inhomogeneous matter dominated model with a varying cosmological constant. Adjusting arbitrary constants of integration one can also achieve acceleration in our model. Aside from an initial…

General Relativity and Quantum Cosmology · Physics 2008-11-26 D. Panigrahi , S. Chatterjee

We attempt to find new symmetries in the space-time structure, leading to a modified gravitation at large length scales, which provides the foundations of a quantum gravity at very low energies. This search begins by considering a unified…

General Relativity and Quantum Cosmology · Physics 2007-09-13 Claudio Nassif
‹ Prev 1 8 9 10 Next ›