Reconsidering astrophysical constraints on macroscopic dark matter

TL;DR

This paper reevaluates astrophysical constraints on macroscopic dark matter candidates, updating limits from white dwarfs, superbursts, and microlensing with more careful analysis and new observational data.

Contribution

It provides revised constraints on macro dark matter properties by improving previous models and incorporating new observational data and analysis techniques.

Findings

Weaker constraints from white dwarfs due to more careful modeling.

Stronger constraints at low cross-section from new white dwarf data.

Updated microlensing constraints on macro dark matter.

Abstract

Macroscopic dark matter -- "macros"-- refers to a broad class of alternative candidates to particle dark matter with still unprobed regions of parameter space. These candidates would transfer energy primarily through elastic scattering with approximately their geometric cross-section. For sufficiently large cross-sections, the linear energy deposition could produce observable signals if a macro were to pass through compact objects such as white dwarfs or neutron stars in the form of thermonuclear runaway, leading to a type IA supernova or superburst respectively. We update the constraints from white dwarfs. These are weaker than previously inferred in important respects because of more careful treatment of the passage of a macro through the white dwarf and greater conservatism regarding the size of the region that must be heated to initiate runaway. On the other hand, we place more stringent constraints on macros at low cross-section, using new data from the Montreal White Dwarf Database. New constraints are inferred from the low mass X-ray binary 4U 1820-30, in which more than a decade passed between successive superbursts. Updated microlensing constraints are also reported.