Constraining burdened PBHs with gravitational waves

TL;DR

This paper explores how memory burden effects in primordial black holes influence gravitational wave spectra, providing constraints on black hole parameters through cosmological measurements.

Contribution

It introduces the concept of memory burden in PBHs and demonstrates its impact on gravitational wave production, linking it to observational constraints.

Findings

Overproduction of GWs constrains PBH parameters

Memory burden affects PBH evaporation dynamics

Cosmological measurements limit backreaction effects

Abstract

We investigate the implications of memory burden on the gravitational wave (GW) spectrum arising from the Hawking evaporation of light primordial black holes (PBHs). By considering both rotating (Kerr) and non-rotating (Schwarzschild) PBHs, we demonstrate that the overproduction of primordial GWs from burdened PBHs could impose stringent constraints on the parameters governing backreaction effects. These constraints, derived from $\Delta N_{\rm eff}$ measurements by Planck and prospective experiments such as CMB-S4 and CMB-HD, offer novel insights into the impact of memory burden on PBH dynamics.