Listening to the Universe through Indirect Detection

TL;DR

This paper explores how astrophysical observations and refined theoretical calculations can enhance indirect detection methods for dark matter, focusing on identifying signals amidst backgrounds and analyzing the Milky Way's center excess.

Contribution

It demonstrates integrated approaches combining astrophysical data and theoretical modeling to improve dark matter detection strategies and interpret signals like the galactic center excess.

Findings

Astrophysical observations can identify promising dark matter observation sites.

Refined theoretical calculations help distinguish dark matter signals from backgrounds.

The galactic center excess is likely due to millisecond pulsars, not dark matter.

Abstract

Indirect detection is the search for the particle nature of dark matter with astrophysical probes. Manifestly, it exists right at the intersection of particle physics and astrophysics, and the discovery potential for dark matter can be greatly extended using insights from both disciplines. This thesis provides an exploration of this philosophy. On the one hand, I will show how astrophysical observations of dark matter, through its gravitational interaction, can be exploited to determine the most promising locations on the sky to observe a particle dark matter signal. On the other, I demonstrate that refined theoretical calculations of the expected dark matter interactions can be used disentangle signals from astrophysical backgrounds. Both of these approaches will be discussed in the context of general searches, but also applied to the case of an excess of photons observed at the center of the Milky Way. This galactic center excess represents both the challenges and joys of indirect detection. Initially thought to be a signal of annihilating dark matter at the center of our own galaxy, it now appears more likely to be associated with a population of millisecond pulsars. Yet these pulsars were completely unanticipated, and highlight that indirect detection can lead to many new insights about the universe, hopefully one day including the particle nature of dark matter.