Postnikov 2014 Non-parametric study of the evolution of the cosmological equation of state with SNeIa, BAO and high redshift GRBs

主要内容:


精彩摘抄:


文章信息:

· Find Similar Abstracts (with default settings below)

· arXiv e-print (arXiv:1401.2939)

· References in the Article

· Also-Read Articles (Reads History)

·

· Translate This Page

Title:		Non-parametric study of the evolution of the cosmological equation of state with SNeIa, BAO and high redshift GRBs
Authors:		Postnikov, Sergey; Giovanna Dainotti, Maria; Hernandez, Xavier; Capozziello, Salvatore
Publication:		eprint arXiv:1401.2939
Publication Date:		01/2014
Origin:		ARXIV
Keywords:		Astrophysics - Cosmology and Extragalactic Astrophysics
Comment:		17 pages, 13 figures, accepted for publication in the ApJ
Bibliographic Code:		2014arXiv1401.2939P

Abstract

We study the dark energy equation of state as a function of redshift in a non-parametric way, without imposing any {\it a priori} $w(z)$ (ratio of pressure over energy density) functional form. As a check of the method, we test our scheme through the use of synthetic data sets produced from different input cosmological models which have the same relative errors and redshift distribution as the real data. Using the luminosity-time $L_{X}-T_{a}$ correlation for GRB X-ray afterglows (the Dainotti et al. correlation), we are able to utilize GRB sample from the {\it Swift} satellite as probes of the expansion history of the Universe out to $z \approx 10$. Within the assumption of a flat FLRW universe and combining SNeIa data with BAO constraints, the resulting maximum likelihood solutions are close to a constant $w=-1$. If one imposes the restriction of a constant $w$, we obtain $w=-0.99 \pm 0.06$ (consistent with a cosmological constant) with the present day Hubble constant as $H_{0}=70.0 \pm 0.6$ ${\rm km} \, {\rm s}^{-1} {\rm Mpc}^{-1}$ and density parameter as $\Omega_{\Lambda 0}=0.723 \pm 0.025$, while non-parametric $w(z)$ solutions give us a probability map which is centred at $H_{0}=70.04 \pm 1$ ${\rm km} \, {\rm s}^{-1} {\rm Mpc}^{-1}$ and $\Omega_{\Lambda 0}=0.724 \pm 0.03$. Our chosen GRB data sample with full correlation matrix allows us to estimate the amount, as well as quality (errors) of data, needed to constrain $w(z)$ in the redshift range extending an order of magnitude in beyond the farthest SNeIa measured.

---

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)