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Hubble expansion in warped braneworld model is addressed in presence of more than one warped extra dimensions. It is shown that while the expansion depends on all the moduli, an exponential nature of the expansion of the scale factor…

High Energy Physics - Theory · Physics 2011-06-10 Narayan Banerjee , Sayantani Lahiri , Soumitra SenGupta

We obtain a closed system of equations for scalar perturbations in a multi-component braneworld. Our braneworld possesses a phantom-like equation of state at late times, $w_{\rm eff} < -1$, but no big-rip future singularity. In addition to…

General Relativity and Quantum Cosmology · Physics 2016-07-27 Satadru Bag , Alexander Viznyuk , Yuri Shtanov , Varun Sahni

Cosmological constraints are usually derived under the assumption of a $6$ parameters $\Lambda$-CDM theoretical framework or simple one-parameter extensions. In this paper we present, for the first time, cosmological constraints in a…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Iain A. Brown , Alan A. Coley , D. Leigh Herman , Joey Latta

The present standard model of cosmology, $\Lambda$CDM, contains some intriguing coincidences. Not only are the dominant contributions to the energy density approximately of the same order at the present epoch, but we note that contrary to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Pim van Oirschot , Juliana Kwan , Geraint F. Lewis

We investigate observational constraints on cosmological parameters combining 15 measurements of the transversal BAO scale (obtained free of any fiducial cosmology) with Planck-CMB data to explore the parametric space of some cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-10 Rafael C. Nunes , Santosh K. Yadav , J. F. Jesus , Armando Bernui

While the standard, six-parameter, spatially flat $\Lambda$CDM model has been highly successful, certain anomalies in the cosmic microwave background bring out a tension between this model and observations. The statistical significance of…

General Relativity and Quantum Cosmology · Physics 2021-09-21 Abhay Ashtekar , Brajesh Gupt , V. Sreenath

The self-tuning brane scenario is an attempt to solve the cosmological constant problem in the context of extra dimensions. Rather than making the vacuum energy small, this approach proceeds by removing the gravitational effect of vacuum…

High Energy Physics - Theory · Physics 2009-11-07 Sean M. Carroll , Laura Mersini

We explore a new class of braneworld models in which the scalar curvature of the (induced) brane metric contributes to the brane action. The scalar curvature term arises generically on account of one-loop effects induced by matter fields…

Astrophysics · Physics 2009-11-07 Varun Sahni , Yuri Shtanov

We present a model with an infinite volume bulk in which a braneworld with a cosmological constant evolves to a static, 4-dimensional Minkowski spacetime. This evolution occurs for a generic class of initial conditions with positive energy…

High Energy Physics - Theory · Physics 2009-10-07 Cedric Deffayet , Gia Dvali , Gregory Gabadadze , Arthur Lue

We extend the idea of mirage cosmology to M-theory. Considering the motion of a probe brane in the M-theory background generated by a stack of non-threshold (M2,M5) bound states, we study the cosmological evolution of the brane universe in…

High Energy Physics - Theory · Physics 2009-11-07 Jin Young Kim

In the brane world scenario, possessing the self-tuning property of the cosmological constant, we study the probability amplitude for an initial state of the Universe to transform to final states with some curvatures. In the Kim, Kyae and…

High Energy Physics - Theory · Physics 2014-11-20 Jihn E. Kim

The observed late-time acceleration of the Universe may be the result of unknown physical processes involving either modifications of gravitation theory or the existence of new fields in high energy physics. In the former case, such…

Astrophysics · Physics 2008-11-26 N. Pires , Zong-Hong Zhu , J. S. Alcaniz

We look for cosmologies with a scalar field (dark energy without cosmological constant), which mimic the standard $\Lambda CDM$ cosmological model yielding exactly the same large-scale geometry described by the evolution of the Hubble…

Astrophysics · Physics 2015-05-13 V. I. Zhdanov , G. Ivashchenko

We revisit the idea of self-tuning the observed cosmological constant to a vanishing value and promote it to a selection criterion of brane-world models, in which our Universe is described by a 3-brane embedded in a 5d bulk. As a concrete…

High Energy Physics - Theory · Physics 2023-08-24 Osmin Lacombe , Shinji Mukohyama

We consider cosmic chronometer (CC) data for the Hubble parameter, quasar (QSO) luminosities data of X-rays and ultraviolet rays emission, and the latest measurements of the present value of the Hubble parameter from 2018 Planck mission…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Bikash R. Dinda , Haveesh Singirikonda , Subhabrata Majumdar

The standard cosmological model, based on general relativity with an inflationary era, is very effective in accounting for a broad range of observed features of the universe. However, the ongoing puzzles about the nature of dark matter and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Roy Maartens

In this letter, we investigate the cosmic expansion scenario of the universe in the framework of $f(R,L_m)$ gravity theory. We consider a non-linear $f(R,L_m)$ model, specifically, $f(R,L_m)=\frac{R}{2}+L_m^n + \beta$, where $n$ and $\beta$…

General Relativity and Quantum Cosmology · Physics 2023-11-02 Lakhan V. Jaybhaye , Raja Solanki , Sanjay Mandal , P. K. Sahoo

Recently, BICEP2 collaboration has released their results on the measurements of the CMB polarizations. In the framework of the $\Lambda$CDM with a power law form of the scalar primordial power spectrum, this new measurement on the B-mode…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-08 Hong Li , Jun-Qing Xia , Xinmin Zhang

In this article, we introduce an innovative parametric representation of the Hubble parameter, providing a model-independent means to explore the dynamics of an accelerating cosmos. The model's parameters are rigorously constrained through…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-16 M. Koussour , N. Myrzakulov , M. K. M. Ali