中文
相关论文

相关论文: Scale invariant cosmology III: dynamical models an…

200 篇论文

The consistency of some dynamical dark energy models based on Gauss-Bonnet invariant, ${\cal G}$, is studied compared with cosmological observational tests. The investigated models are modified form of Gauss Bonnet dark energy, MGB-DE and…

广义相对论与量子宇宙学 · 物理学 2019-06-14 Z. Molavi , A. Khodam-Mohammadi

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…

宇宙学与河外天体物理 · 物理学 2020-08-10 Rafael C. Nunes , Santosh K. Yadav , J. F. Jesus , Armando Bernui

We review the current status of cosmological parameters, dark energy and large-scale structure, from a theoretical and observational perspective. We first present the basic cosmological parameters and discuss how they are measured with…

天体物理学 · 物理学 2007-05-23 S. E. Deustua , R. Caldwell , P. Garnavich , L. Hui , A. Refregier

We present a collection of new, open-source computational tools for numerically modeling recent large-scale observational data sets using modern cosmology theory. Specifically, these tools will allow both students and researchers to…

宇宙学与河外天体物理 · 物理学 2013-05-22 Jacob Moldenhauer , Larry Engelhardt , Keenan Stone , Ezekiel Shuler

The dynamical aspect of accelerating cosmological model has been studied in this paper in the context of modified symmetric teleparallel gravity, the $f(Q)$ gravity. Initially, we have derived the dynamical parameters for two well known…

广义相对论与量子宇宙学 · 物理学 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or…

宇宙学与河外天体物理 · 物理学 2017-11-07 Tomasz Denkiewicz , Vincenzo Salzano

Scalar field dynamics may give rise to a nonzero cosmological variation of fundamental constants. Within different scenarios based on the unification of gauge couplings, the various claimed observations and bounds may be combined in order…

高能物理 - 唯象学 · 物理学 2010-04-21 Thomas Dent , Steffen Stern , Christof Wetterich

The possibility of mass in the context of scale-invariant, generally covariant theories, is discussed. The realizations of scale invariance which are considered, are in the context of a gravitational theory where the action, in the first…

广义相对论与量子宇宙学 · 物理学 2009-10-31 E. I. Guendelman

We consider scalar perturbations of energy--density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine--tuning for graceful exit, towards the standard Friedman eras of observed…

广义相对论与量子宇宙学 · 物理学 2007-05-23 S. Capozziello , G. Lambiase , G. Scarpetta

In this paper, we study the cosmological dynamics of scalar fields with O(N) symmetry in general potentials. We compare the phase space of the dynamical systems of the quintessence and phantom and give the conditions for the existence of…

天体物理学 · 物理学 2009-11-10 Jian-gang Hao , Xin-zhou Li

Small-scale discrepancies in the standard Lambda cold dark matter paradigm have motivated the exploration of alternative dark matter (DM) models, such as warm dark matter (WDM). We investigate the constraining power of galaxy scaling…

We focus on the class of cosmological models with a time-evolving vacuum energy density of the form $\rho_\Lambda=C_0+C_1 H+C_2 H^2$, where $H$ is the Hubble rate. Higher powers of $H$ could be important for the early inflationary epoch,…

宇宙学与河外天体物理 · 物理学 2015-03-13 Adria Gomez-Valent , Joan Sola

The standard concordance model of the Universe is based on the cosmological constant as the driver of accelerating expansion. This concordance model is being subjected to a growing range of inter-locking observations. In addition to using…

宇宙学与河外天体物理 · 物理学 2015-06-16 Sahba Yahya , Marina Seikel , Chris Clarkson , Roy Maartens , Mathew Smith

We use the Szekeres inhomogeneous cosmological models to study the growth of large-scale structure in the universe including nonzero spatial curvature and a cosmological constant. In particular, we use the Goode and Wainwright formulation,…

宇宙学与河外天体物理 · 物理学 2015-06-12 Austin Peel , Mustapha Ishak , M. A. Troxel

Observations of an apparent acceleration in the expansion rate of the universe, derived from measurements of high-redshift supernovae, have been used to support the hypothesis that the universe is permeated by some form of dark energy. We…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Robin Booth

Keeping in mind the current picture of an accelerating and flat Universe, some specific dynamical models of the cosmological term $\Lambda$ have been selected for investigating the nature of dark energy. Connecting the free parameters of…

天体物理学 · 物理学 2008-11-26 Saibal Ray , Utpal Mukhopadhyay , Xin-He Meng

All cosmological observations to date are consistent with adiabatic, Gaussian and nearly scale invariant initial conditions. These findings provide strong evidence for a particular symmetry breaking pattern in the very early universe (with…

宇宙学与河外天体物理 · 物理学 2015-08-26 Jens Chluba , Jan Hamann , Subodh P. Patil

Choosing the three phenomenological models of the dynamical cosmological term $\Lambda$, viz., $\Lambda \sim (\dot a/a)^2$, $\Lambda \sim {\ddot a/a}$ and $\Lambda \sim \rho$ where $a$ is the cosmic scale factor, it has been shown by the…

广义相对论与量子宇宙学 · 物理学 2009-09-28 Saibal Ray , P. C. Ray , Partha Pratim Ghosh , Utpal Mukhopadhyay , Partha Chowdhury

The onset of stochasticity is measured in $\Lambda$CDM cosmological simulations using a set of classical observables. It is quantified as the local derivative of the logarithm of the dispersion of a given observable (within a set of…

天体物理学 · 物理学 2009-11-13 Jerome Thiebaut , Christophe Pichon , Thierry Sousbie , Simon Prunet , D. Pogosyan

We consider spherically symmetric inhomogeneous dust models with a positive cosmological constant, $\Lambda$, given by the Lemaitre-Tolman-Bondi metric. These configurations provide a simple but useful generalization of the Lambda-CDM model…

广义相对论与量子宇宙学 · 物理学 2015-03-14 Roberto A. Sussman , German Izquierdo
‹ 上一页 1 8 9 10 下一页 ›