English
Related papers

Related papers: Evolution of Generalized Brans-Dicke parameter wit…

200 papers

We report strong cosmological constraints on the Brans-Dicke (BD) theory of gravity using Cosmic Microwave Background data from Planck.We consider two types of models. First, the initial condition of the scalar field is fixed to give the…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 A. Avilez , C. Skordis

We show that Friedmann-Robertson-Walker (FRW) geometry with flat spatial section in quantized (Wheeler deWitt quantization) Brans Dicke (BD) theory reveals a rich phase structure owing to anomalous breaking of a classical symmetry, which…

General Relativity and Quantum Cosmology · Physics 2016-10-17 Sridip Pal

We develop a model for the evolution of economic entities within a geographical type of framework. On a square symmetry lattice made of three (economic) regions, firms, described by a scalar fitness, are allowed to move, adapt, merge or…

Statistical Mechanics · Physics 2009-11-10 Marcel Ausloos , Paulette Clippe , Andrzej Pekalski

In this paper, we investigate a scalar field Brans-Dicke cosmological model in Lyra's geometry which is based on the modifications in geometrical term as well as energy term of Einstein's field equations. We have examined the validity of…

General Relativity and Quantum Cosmology · Physics 2023-11-15 Rajendra Prasad , Lalit Kumar Gupta , Anil Kumar Yadav

We consider a generalized Brans-Dicke model in which the scalar field has a self-interacting potential function. The scalar field is also allowed to couple non-minimally with the matter part. We assume that it has a chameleon behavior in…

High Energy Physics - Theory · Physics 2019-01-21 Yousef Bisabr

We study the averaged action of the Randall-Sundrum model with a time dependent metric ansatz. It can be reformulated in terms of a Brans-Dicke action with time dependent Newton's constant. We show that the physics of early universe,…

High Energy Physics - Theory · Physics 2009-11-07 Somdatta Bhattacharya , Debajyoti Choudhury , Dileep P. Jatkar , Anjan Ananda Sen

In a Brans-Dicke (BD) cosmological model, the energy density associated with some scalar field decreases as $\displaystyle a^{{-2}(\frac{\omega_{o}+ {\frac12}%}{\omega_{o}+1})} $ with the scale factor $a(t)$ of the Universe, giving a matter…

Astrophysics · Physics 2009-10-31 S. del Campo , N. Cruz

Persistent evidence for a cosmic hemispherical asymmetry in the temperature field of cosmic microwave background (CMB) as observed by both WMAP as well as PLANCK increases the possibility of its cosmological origin. Presence of this signal…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-28 Suvodip Mukherjee , Pavan K. Aluri , Santanu Das , Shabbir Shaikh , Tarun Souradeep

A conformal transformation of a static or stationary spacetime by a time dependent conformal scale factor ${S(\tau )}^2$ is one of the methods of producing a cosmological spacetime. Using this knowledge and Brans-Dicke (BD) field equations,…

General Relativity and Quantum Cosmology · Physics 2023-12-07 Dilek K. Çiftci , Ali Demirözlü

Recently, interesting braneworld cosmologies in the Randall-Sundrum scenario have been constructed using a bulk spacetime which corresponds to a charged AdS black hole. In particular, these solutions appear to `bounce', making a smooth…

High Energy Physics - Theory · Physics 2009-11-10 Jordan L. Hovdebo , Robert C. Myers

The evolution of the cosmological perturbations is studied in the context of the Randall-Sundrum brane world scenario, in which our universe is realized on a three-brane in the five dimensional Anti-de Sitter(AdS) spacetime. We develop a…

High Energy Physics - Theory · Physics 2009-10-31 Kazuya Koyama , Jiro Soda

We investigate observational constraints on the Brans-Dicke cosmological model using observational data coming from distant supernovae type Ia, the Hubble function $H(z)$ measurements, information coming from the Alcock-Paczy{\'n}ski test,…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-15 Orest Hrycyna , Marek Szydlowski , Michal Kamionka

Anisotropic spherically symmetric solutions within the framework of the Brans-Dicke theory are uncovered through a unique gravitational decoupling approach involving a minimal geometric transformation. This transformation effectively…

General Relativity and Quantum Cosmology · Physics 2023-11-01 Kazuharu Bamba , M. Z. Bhatti , Z. Yousaf , Z. Shoukat

It has been shown that Brans-Dicke (BD) theory in anisotropic cosmological model can alone solve the quintessence problem and we have accelerated expanding universe without any quintessence matter. Also the flatness problem has been…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Subenoy Chakraborty , N. C. Chakraborty , Ujjal Debnath

We numerically study the dual field theory evolution of five-dimensional asymptotically anti-de Sitter solutions of supergravity that develop cosmological singularities. The dual theory is an unstable deformation of the N = 4 gauge theory…

High Energy Physics - Theory · Physics 2010-12-09 Lorenzo Battarra , Thomas Hertog

Based on the idea that the components of a cosmological metric may be determined by the total gravitational potential of the universe, the scalar field $\phi=1/G$ in the Jordan-Brans-Dicke (JBD) theory is introduced as evolving with the…

General Relativity and Quantum Cosmology · Physics 2023-05-18 Onder Dunya , Metin Arik

We present a reformulation of quantum adiabatic theory in terms of an emergent electromagnetic framework, emphasizing the physical consequences of geometric structures in parameter space. Contrary to conventional approaches, we demonstrate…

Quantum Physics · Physics 2025-08-15 Georgios Konstantinou

We consider bouncing cosmologies in which an ekpyrotic contraction phase with w >> 1 is followed by a bouncing phase with w < -1 that violates the null energy condition. The bouncing phase, induced by ghost condensation, is designed to…

High Energy Physics - Theory · Physics 2013-05-29 BingKan Xue , Paul J. Steinhardt

We consider Brans-Dicke theory with a self-interacting potential in Einstein conformal frame. We show that an accelerating expansion is possible in a spatially flat universe for large values of the Brans-Dicke parameter consistent with…

General Relativity and Quantum Cosmology · Physics 2012-01-26 Yousef Bisabr

The Brans-Dicke model with a variable cosmological term ($BD\Lambda$) has been investigated with use of the coupling constant of $\omega=10^4$. Parameters inherent in this model are constrained from comparison between Big Bang…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 E. P. B. A. Thushari , R. Nakamura , M. Hashimoto , K. Arai
‹ Prev 1 4 5 6 7 8 10 Next ›