High Longevity Microlensing Events and Dark Matter Black Holes

TL;DR

This paper explores the potential of high longevity microlensing events to detect massive dark matter black holes in the halo, extending the mass range beyond previous limits and highlighting their significance for cosmology.

Contribution

It proposes that black holes with masses up to 10^6 solar masses could be detected through long-duration microlensing events, expanding the scope of dark matter searches.

Findings

High mass black holes could produce detectable long-duration microlensing events.

Such events could reveal a significant population of halo black holes.

Implications for understanding dark matter and cosmological entropy.

Abstract

Gravitational microlensing has been employed to identify massive halo objects by their amplification of distant sources; MACHO searches have studied event times $2 h \lesssim t_0 \lesssim 2 y$ corresponding masses in the range $10^{-6} M_{\odot} \lesssim M \lesssim 100 M_{\odot}$. We suggest that larger masses up to $10^6 M_{\odot}$ are also of considerable interest. It has not been excluded that there is a significant number of halo black holes with such high masses as suggested by cosmological entropy considerations and potentially detectable by high longevity microlensing events.