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Related papers: Very high energy gamma-rays and the Hubble paramet…

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The Hubble parameter H0 still not very well measured. Although the Hubble Key Project, Chandra and WMAP gave good estimates, the uncertainties remain quite large. In this brief report, we suggest an original and independent method to derive…

Astrophysics · Physics 2009-11-13 A. Barrau , A. Gorecki , J. Grain

In this work we study how the cosmological parameter, the Hubble constant $H_0$, can be constrained by observation of very high energy (VHE) $\gamma$-rays at the TeV scale. The VHE $\gamma$-rays experience attenuation by background…

Astrophysics · Physics 2009-11-09 Xiao-Jun Bi , Qiang Yuan

A measurement of the expansion rate of the Universe (that is the Hubble constant, H0) is derived here using the gamma-ray attenuation observed in the spectra of gamma-ray sources produced by the interaction of extragalactic gamma-ray…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-19 A. Domínguez , F. Prada

The Hubble constant $H_{0}$ and matter density $\Omega_{m}$ of the Universe are measured using the latest $\gamma$-ray attenuation results from Fermi-LAT and Cherenkov telescopes. This methodology is based upon the fact that the…

Galactic Gamma ray astronomy at very high energy (E > 30 TeV) is a vital tool in the study of the non-thermal universe. The interpretation of the observations in this energy region requires the precise modeling of the attenuation of photons…

High Energy Astrophysical Phenomena · Physics 2016-09-28 Silvia Vernetto , Paolo Lipari

The Hubble constant ($H_0$) is one of the most important parameters in the standard $\rm \Lambda CDM$ model. The measurements given by the main two methods show a gap larger than $4\sigma$, which is known as Hubble tension. Fast radio…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-18 D. H. Gao , Q. Wu , J. P. Hu , S. X. Yi , X. Zhou , F. Y. Wang , Z. G. Dai

The attenuation produced by extragalactic background light (EBL) in $\gamma$-ray spectra of blazars has been used to constrain the Hubble constant ($H_0$) and matter density ($\Omega_{\rm m}$) of the Universe. We propose to estimate $H_0$…

High Energy Astrophysical Phenomena · Physics 2019-09-11 Houdun Zeng , Dahai Yan

A new method of measuring cosmology with gamma-ray bursts(GRBs) has been proposed by Liang and Zhang recently. In this method, only observable quantities including the rest frame peak energy of the \nu F_\nu spectrum (E'_p), the isotropic…

Astrophysics · Physics 2009-11-13 F. Y. Wang , Z. G. Dai

Bidirectional relativistic proper motions of radio components of nearby extragalactic sources give a strong constraint on the determination of the Hubble constant $H_0$. Under the assumption that the real velocity of radio components of…

Astrophysics · Physics 2009-10-31 Yi-Ping Qin

Some gamma-ray burst (GRB) spectra exhibit high energy tails with the highest photon energy detected at 18 GeV. The spectral slope of the high-energy tails is sufficiently flat in nu F_nu to consider the possibility of their detection at…

Astrophysics · Physics 2009-10-28 Karl Mannheim , Dieter Hartmann , Burkhardt Funk

Joint analysis of Cosmic Microwave Background, Baryon Acoustic Oscillation, and supernova data has enabled precision estimation of cosmological parameters. New programs will push to 1% uncertainty in the dark energy equation of state and…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-26 Lincoln Greenhill , Elizabeth Humphreys , Wayne Hu , Lucas Macri , David Murphy , Karen Masters , Yoshiaki Hagiwara , Hideyuki Kobayashi , Yasuhiro Murata

The Hubble constant ${H}_0$ is a crucial parameter in cosmology. However, different cosmic observations have resulted in varying posterior results for ${H}_0$, leading to what is known as the ${H}_0$ tension. In order to address this issue,…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-18 Jiaze Gao , Zhihuan Zhou , Minghui Du , Rui Zou , Jianping Hu , Lixin Xu

We use the measurement of gamma-ray burst (GRB) distances to constrain dark energy cosmological model parameters. We employ two methods for analyzing GRB data - fitting luminosity relation of GRBs in each cosmology and using distance…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-30 Lado Samushia , Bharat Ratra

We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

Very high energy (VHE) gamma-rays from extragalactic sources, interacting by gamma-gamma collisions with diffuse intergalactic radiation fields, provide an alternative way to constrain the diffuse background light, completely independent of…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Luigi Costamante

We generalise the procedure for joint estimation of cosmological parameters to allow freedom in the relative weights of various probes. This is done by including in the joint Likelihood function a set of 'Hyper-Parameters', which are dealt…

Astrophysics · Physics 2007-05-23 Ofer Lahav

A small air shower array operating over many years has been used to search for ultra-high energy (UHE) gamma radiation ($\geq 50$ TeV) associated with gamma-ray bursts (GRBs) detected by the BATSE instrument on the Compton Gamma-Ray…

Astrophysics · Physics 2009-10-28 S. P. Plunkett , M. Delaney , B. McBreen , K. J. Hurley , C. T. O'Sullivan

We establish a cosmological-model-independent method to determine the Hubble constant $H_0$ from the localized fast radio bursts (FRBs) and the Hubble parameter measurements from cosmic chronometers and obtain a first such determination…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-12 Yang Liu , Hongwei Yu , Puxun Wu

The pair-production absorption of high-energy gamma-rays by intergalactic low-energy photons is expected to produce a high-energy cutoff in the spectra of extragalactic sources which is a sensitive function of redshift. We first discuss the…

Astrophysics · Physics 2007-05-23 F. W. Stecker

As the advent of precision cosmology, the Hubble constant ($H_0$) inferred from the Lambda Cold Dark Matter fit to the Cosmic Microwave Background data is increasingly in tension with the measurements from the local distance ladder. To…

Astrophysics of Galaxies · Physics 2021-12-08 Wei-Jian Lu , Yi-Ping Qin
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