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Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero…

Astrophysics · Physics 2007-05-23 D. Pogosyan , J. R. Bond , C. R. Contaldi

The standard cosmological model is in the midst of a stress test, thanks to the tension between supernovae-based measurements of the Hubble constant $H_{0}$ and inferences of its values from Cosmic Microwave Background (CMB) anisotropies.…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-05 K. Rezazadeh , A. Ashoorioon , D. Grin

A cosmological analysis considering the inclusion of dark energy and dark matter cosmic components in the context of some particular cases for intersecting S-brane solutions is presented and discussed. Direct solution of $d$-dim field…

High Energy Physics - Theory · Physics 2016-03-30 J. A. Agudelo , H. I. Arcos , A. Idarraga

Early data from the James Webb Space Telescope (JWST) has uncovered the existence of a surprisingly abundant population of very massive galaxies at extremely high redshift, which are hard to accommodate within the standard $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-25 Shahnawaz A. Adil , Upala Mukhopadhyay , Anjan A. Sen , Sunny Vagnozzi

Dark Energy is some of the weirdest and most mysterious stuff in the universe that tends to increase the rate of expansion of the universe. Two commonly known forms of dark energy are the cosmological constant, a constant energy density…

General Relativity and Quantum Cosmology · Physics 2010-04-28 Ishwaree P. Neupane , Holly Trowland

We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter $\Lambda$CDM by including dynamical dark energy (DE: $w_0$, $w_a$), the sum of neutrino masses ($\sum m_{\nu}$), the…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-19 Shouvik Roy Choudhury , Teppei Okumura

While $\Lambda$CDM provides a good fit to cosmological data, it fails to address many of the outstanding questions in contemporary cosmology. Chief among these are the Hubble tension and the apparent dynamical nature of dark energy as…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Amin Aboubrahim , Pran Nath

We present a model of dark energy based on the string effective action, and on the assumption that the dilaton is strongly coupled to dark matter. We discuss the main differences between this class of models and more conventional models of…

High Energy Physics - Theory · Physics 2017-08-23 M. Gasperini

The presence of dark energy in the Universe is inferred directly and indirectly from a large body of observational evidence. The simplest and most theoretically appealing possibility is the vacuum energy density (cosmological constant).…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz

By using a Markov Chain Monte Carlo simulation, we investigate cosmological constraints on the ghost dark energy (GDE) model in the framework of the Brans-Dicke (BD) theory. A combination of the latest observational data of the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-13 Hamzeh Alavirad , Ahmad Sheykhi

The predicted present-day amplitude of matter fluctuations based on cosmic microwave background (CMB) anisotropy data has sometimes been found discrepant with more direct measurements of late-time structure. This has motivated many…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-14 Alex Laguë , Fiona McCarthy , Mathew Madhavacheril , J. Colin Hill , Frank J. Qu

We investigate a phenomenological non-gravitational coupling between dark energy and dark matter, where the interaction in the dark sector is parameterized as an energy transfer either from dark matter to dark energy or the opposite. The…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-11 Riccardo Murgia , Stefano Gariazzo , Nicolao Fornengo

Soft cosmology is an extension of standard cosmology allowing for a scale-dependent equation-of-state (EoS) parameter in the dark sectors, which is one of the properties of soft materials in condensed-matter physics, that may arise either…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-12 Emmanuel N. Saridakis , Weiqiang Yang , Supriya Pan , Fotios K. Anagnostopoulos , Spyros Basilakos

We use numerical simulations of different dark energy cosmologies to investigate the concentration-mass (c-M) relation in galaxy clusters. In particular, we consider a reference Lambda cold dark matter (LambdaCDM) model, two models with…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-12 Cristiano De Boni

In this paper we show that in some important cases 4-dimensional data can be extracted from superstring theory such that a) the data are 4 Euclidean geometries embedded in standard $\mathbb{R}^{4}$, b) these data depend on NS and D brane…

High Energy Physics - Theory · Physics 2011-04-08 T. Asselmeyer-Maluga , J. Krol

In this paper, we have investigated an anisotropic cosmological model in $f(Q)$ gravity with string fluid in LRS Bianchi type-I universe. We have considered the arbitrary function $f(Q)=Q+\alpha\sqrt{~Q}+2\Lambda$ where $\alpha$ is model…

General Relativity and Quantum Cosmology · Physics 2023-03-02 Dinesh Chandra Maurya , Archana Dixit , Anirudh Pradhan

The recent astronomical measurements of distant supernovae as well as other observations indicate that our universe is presently accelerating. There are different proposals for the explanation of this acceleration, such as the cosmological…

Astrophysics · Physics 2008-11-26 Marek Szydlowski , Wlodzimierz Godlowski

Observational growth rate data had been derived from observations of redshift distortions in galaxy redshift surveys. Here we use the growth rate data to place constraints on the dark energy model parameters. By performing a joint analysis…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 K. Shi , Y. F. Huang , T. Lu

Several dark energy models on the brane are investigated. They are compared with corresponding theories in the frame of 4d Friedmann-Robertson-Walker cosmology. To constrain the parameters of the models considered, recent observational…

General Relativity and Quantum Cosmology · Physics 2015-06-12 A. V. Astashenok , E. Elizalde , J. de Haro , S. D. Odintsov , A. V. Yurov

The coupled dark energy model provides a possible approach to mitigate the coincidence problem of cosmological standard model. Here, the coupling term is assumed as $\bar{Q}=3H\xi_x\bar{\rho}_x$, which is related to the interaction rate and…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-11 Weiqiang Yang , Hang Li , Yabo Wu , Jianbo Lu