Related papers: Cosmography by GRBs
Gamma-ray bursts (GRBs) are among the most powerful sources in the universe. In the recent years, GRBs have been proposed as a complementary probe to type Ia supernovae (SNIa). However, as is well known, there is a circularity problem in…
Gamma-ray bursts (GRBs) are a potential tool to probe high-redshift universe. However, the circularity problem enforces people to find model-independent methods to study the luminosity correlations of GRBs. Here, we present a new method…
The non-linear relation between X-ray and UV luminosity in quasars can be used to estimate their distance. Recently, we have shown that despite the large dispersion of the relation, a Hubble Diagram made of large samples of quasars can…
In recent years there has been considerable activity in using gamma-ray bursts as cosmological probes for determining global cosmological parameters complementing results from type Ia supernovae and other methods. This requires a…
We calibrate the distance and reconstruct the Hubble diagram of gamma-ray bursts (GRBs) using deep learning. We construct an artificial neural network, which combines the recurrent neural network and Bayesian neural network, and train the…
The redshift-distance modulus relation, the Hubble Diagram, derived from Cosmological General Relativity has been extended to arbitrarily large redshifts. Numerical methods were employed and a density function was found that results in a…
The results from the Supernova Cosmology Project indicate a relation between cosmic distance and redshift that corresponds to an accelerating Universe, and, as a consequence, the presence of an energy component with negative pressure. This…
We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…
In this note, we consider the observational constraints on some cosmological models by using the 307 Union type Ia supernovae (SNIa), the 32 calibrated Gamma-Ray Bursts (GRBs) at $z>1.4$, the updated shift parameter $R$ from WMAP 5-year…
Strong gravitational lensing along with the distance sum rule method can constrain both cosmological parameters as well as density profiles of galaxies without assuming any fiducial cosmological model. To constrain galaxy parameters and…
In the present work, by the help of the newly released Union2 compilation which consists of 557 Type Ia supernovae (SNIa), we calibrate 109 long Gamma-Ray Bursts (GRBs) with the well-known Amati relation, using the cosmology-independent…
In this paper, a parametrization describing the kinematical state of the universe via cosmographic approach is considered, where the minimum input is the assumption of the cosmological principle, i.e. the Friedmann-Robertson-Walker metric.…
We use the Simon, Verde, & Jimenez (2005) determination of the redshift dependence of the Hubble parameter to constrain cosmological parameters in three dark energy cosmological models. We consider the standard $\Lambda$CDM model, the XCDM…
Gamma-Ray Bursts (GRBs) offer a potential way to extend the Hubble diagram to very high redshifts and to constrain the nature of dark energy in a way complementary to distant type Ia supernovae. However, gravitational lensing systematically…
The Hubble diagram (HD) is a plot that contains luminous distance modulus presented with respect to the redshift. The distance modulus--redshift relation of the most well-known ``standard candles'', the type Ia supernovae (SN), is a crucial…
Correlations among pulse properties in the prompt emission of long GRBs can potentially be used as cosmological distance indicators to estimate redshifts of GRBs to which these pulses belong. We demonstrate application of this technique to…
The recent $\sim 4 \, \sigma$ Hubble constant, $H_{0}$, tension is observed between the value of $H_{0}$ from the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SNe Ia). It is a decade since this tension is excruciating the…
The goal of the present paper is to assess the usefulness of quasars as cosmological distance indicators. We calibrate, in a model-independent way, the non-linear relation between X-ray and UV emission to derive quasar luminosity distances.…
Gamma Ray Bursts are among the most powerful astrophysical sources and they release up to 1.e54 erg, if isotropic, in less than few hundred seconds. Their detection in the hard X/gamma ray band (at energies >10 keV) and out to very high…
We use the correlation relation between the energy emitted by the GRBs in their prompt phases and the X-ray afterglow fluxes, in an effort to constrain cosmological parameters and aiming to construct a Hubble diagram at high redshifts, i.e.…