GRBs and fundamental physics

TL;DR

Gamma-ray bursts serve as powerful tools to explore the early universe, cosmic expansion, dark energy, star formation, reionization, and fundamental physics principles like Lorentz invariance and Einstein's Equivalence Principle.

Contribution

This paper reviews recent progress in using GRBs to probe cosmology and fundamental physics, highlighting their unique role in testing theories beyond current observational limits.

Findings

GRBs can constrain cosmic acceleration and dark energy evolution.

GRBs provide insights into high-redshift star formation and reionization.

High-energy GRB photons can test Lorentz invariance and Einstein's Equivalence Principle.

Abstract

Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So, they are unique tools to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal evolution of the Universe. First, they can be used to constrain the history of cosmic acceleration and the evolution of dark energy in a redshift range hardly achievable by other cosmological probes. Second, long GRBs are believed to be formed by collapse of massive stars. So they can be used to derive the high-redshift star formation rate, which can not be probed by current observations. Moreover, the use of GRBs as cosmological tools could unveil the reionization history and metal evolution of the Universe, the intergalactic medium (IGM) properties and the nature of first stars in the early universe. But beyond that, the GRB high-energy photons can be applied to constrain Lorentz invariance violation (LIV) and to test Einstein's Equivalence Principle (EEP). In this paper, we review the progress on the GRB cosmology and fundamental physics probed by GRBs.