Speaker: Nancy Aggarwal, UC Davis Physics

Title: Dark matter searches using gravitational-wave detectors

Abstract:  In this talk I will talk about a precision measurement experiment to look for higher frequency gravitational waves (GWs). I will also summarize projects looking for dark matter signals in GW-detectors in multiple frequency bands.
Gravitational waves (GWs) at frequencies higher than the LIGO band can bring us completely new information about the universe. Besides being the most-interesting frequency region for looking at cosmological phenomena, they can also convey signatures of dark matter candidates like ultralight bosons through blackhole superradiance and light primordial blackholes (PBHs). I will introduce a new global initiative to study GW sources and detectors at ultra-high-frequencies (MHz-GHz), as well as a new experiment to look for GWs in the radio frequency band (10 kHz to 300 kHz) using levitated optomechanical sensors. I will summarize the design of this radio-frequency levitated sensor detector (LSD), the current experimental progress, as well as a path forward for future improvements.
I will also show upper limits that LSD could place on the light PBHs, as well as recent upper limits on ultralight PBHs using a new analysis technique on LIGO data. If time permits, I will also show a new way to look for dilatonic dark matter in the auxiliary channels of LIGO.
Finally, I will give a sneak-peek into future experiments that will shine light on numerous questions in fundamental physics ranging from gravitational waves, dark matter, cosmology, beyond-the-standard-model physics, and quantum gravity.