GRB Cosmology

Volker Bromm; Abraham Loeb

Home/Archive/arXiv

arXiv · 0706.2445

GRB Cosmology

Volker Bromm·Abraham Loeb

View original source ↗Read source document ↗Export metadata ↓

Abstract

Current observations are about to open up a direct window into the final frontier of cosmology: the first billion years in cosmic history when the first stars and galaxies formed. Even before the launch of the James Webb Space Telescope, it might be possible to utilize Gamma-ray Bursts (GRBs) as unique probes of cosmic star formation and the state of the intergalactic medium (IGM) up to redshifts of several tens, when the first (Population III) stars had formed. The Swift mission, or future satellites such as EXIST, might be the first observatories to detect individual Population III stars, provided that massive metal-free stars were able to trigger GRBs. Spectroscopic follow-up observations of the GRB afterglow emission would allow to probe the ionization state and metal enrichment of the IGM as a function of redshift.

Explore related subjects

astro-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Volker Bromm, Abraham Loeb. 2007-07-28. GRB Cosmology. https://arxiv.org/abs/0706.2445

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

The mildly nonlinear imprint of structure on the CMB: the $O(\ell)$ couplings are lensing and aberration

The exact 1+3 covariant multipole hierarchy for the CMB brightness contains kinematic couplings between the shear, acceleration and vorticity of the observers and the temperature multipoles, whose coefficients grow linearly in $\ell$. They are products of first-order quantities, so linearization about FLRW removes them. Here they are kept as sources in a weakly nonlinear extension of the almost-FLRW temperature anisotropies, and evaluated in the aligned-wavevector, weak-coupling limit. In the Newtonian frame the acceleration terms cancel at leading order in $1/\ell$. In the total (CDM) frame the shear terms cancel in the same way, to a residual of about $3/\ell$ of either term. Earlier versions of this paper reported that the total-frame terms do not cancel, and inferred a mildly nonlinear Rees-Sciama imprint near $\ell \sim 100 - 300$. That result came from a sign misprint in the $\ell-2$ shear coupling and is withdrawn; see the Note added. The $O(\ell)$ couplings are the multipole form of gravitational lensing and observer aberration, both already in the standard treatment. The explicit kinematic couplings written here are only part of the full second-order propagation source; the perturbed free-streaming contribution is linearized away in this paper.

astro-ph↗

arXiv2026

Cosmic Conundrums with Quantum Corrections

Darh energy was discovered over 25 years ago and we do not have an explanation of it. Dark matter comprises 95% of matter in the universe and we still don't know what it is. The Webb telescope has been finding fully formed galaxies with massive black holes millions of times the mass of the sun in the early universe and we don't have any explanation. A quantum density limitation will be used to solve these and other outstanding problems.

astro-ph↗

arXiv2026

On binary pulsars and the force of gravity

The energy-momentum budget of the astrophysical systems can be studied by the exact local conservation equation derived by Landau and Lifshitz. We show that a similar equation is valid for the Einstein-Cartan gravity. We reanalyze a binary pulsar system using the Landau-Lifshitz conservation equation and show that the orbital period change rate can be completely understood as a curvature backreaction process. Taking into account the detailed theoretical and observational research of relativistic binary pulsar systems, especially the system of Hulse and Taylor, we conclude that general relativity and astrophysical observations rule out the existence of gravitational radiation. We comment upon the LIGO GW events and their alternative explanation, as well as the recent pulsar timing arrays data.

astro-ph↗