Evidence of Deterministic Components in the Apparent Randomness of GRBs: Clues of a Chaotic Dynamic

TL;DR

This paper investigates the complex temporal structures of gamma-ray bursts (GRBs) and finds evidence suggesting that their apparent randomness may be driven by underlying chaotic dynamics, revealing a strange attractor in their phase space.

Contribution

The study applies nonlinear analysis combining Singular Spectrum Analysis and Chaos Theory to identify non-stochastic, chaotic components in GRB emissions, offering new insights into their underlying physical processes.

Findings

Evidence of non-stochastic short-term variability in GRBs

Detection of a strange attractor in the phase space of GRB emissions

Implications for understanding ultra-relativistic processes in GRB explosions

Abstract

Prompt {\gamma}-ray emissions from gamma-ray bursts (GRBs) exhibit a vast range of extremely complex temporal structures with a typical variability time-scale significantly short - as fast as milliseconds. This work aims to investigate the apparent randomness of the GRB time profiles making extensive use of nonlinear techniques combining the advanced spectral method of the Singular Spectrum Analysis (SSA) with the classical tools provided by the Chaos Theory. Despite their morphological complexity, we detect evidence of a non stochastic short-term variability during the overall burst duration - seemingly consistent with a chaotic behavior. The phase space portrait of such variability shows the existence of a well-defined strange attractor underlying the erratic prompt emission structures. This scenario can shed new light on the ultra-relativistic processes believed to take place in GRB explosions and usually associated with the birth of a fast-spinning magnetar or accretion of matter onto a newly formed black hole.