UCLA Dark Matter 2025

Session

SESSION 8: Dark Matter Theory (CHAIR: Tommaso Treu -UCLA)

25 Mar 2025, 13:30

UCLA Physics and Astronomy Building 1-425

49. Cosmic Millicharge Background and Reheating Probes

Yu-Dai Tsai (University of California, Irvine)

25/03/2025, 13:30

Talk

We demonstrate that the searches for dark sector particles can provide probes of reheating scenarios, focusing on the cosmic millicharge background produced in the early universe. We discuss two types of millicharge particles (mCPs): either with, or without, an accompanying dark photon. These two types of mCPs have distinct theoretical motivations and cosmological signatures. We discuss...

23. Hardware upgrades to the DEAP-3600 dark matter detector to enhance WIMP sensitivity (*)

Theo Hugues (Queen's University)

25/03/2025, 13:45

Talk

This talk describes hardware upgrades for the DEAP-3600 dark matter direct detection experiments, which uses over 3 tonnes of liquid argon (LAr) as a scintillation target and is located 2 km underground at SNOLAB in Sudbury, Canada. These upgrades aim to maximize the detector's sensitivity to WIMP dark matter by removing the dominant sources of background. Operations with the upgraded detector...

207. Dark matter halos at z > 6 through gas kinematics

John Silverman

25/03/2025, 14:00

Talk

NA

145. Macroscopic dark matter: fermi balls and black holes

zachary picker (UCLA)

25/03/2025, 14:45

Talk

I will discuss the formation of macroscopic dark matter from interacting dark sectors. Specifically,Fermi balls can form in dark sectors with a heavy fermion and a light scalar mediated Yukawa force. I'll discuss the behavior of these Fermi balls and the conditions under which they will collapse to form primordial black holes. Based on arXiv:2411.17074.

208. Gravitational Waves from Black Hole formation

Chris Kouvaris

25/03/2025, 15:00

Talk

In an early matter phase of the Universe, perturbations can
grow and lead to the formation of primordial black holes that can account
fully or partially for the observed dark matter abundance. During
formation, such primordial black holes can produce gravitational waves
that can be detected in interferometers or in Pulsar Timing Arrays. I'll
present results from numerical simulations...

212. New Probes of Fundamental Physics in Diffuse Astrophysical Backgrounds

Volodymyr Takhistov

25/03/2025, 15:15

Talk

The Universe could be filled with faint relics of new fundamental processes—diffuse backgrounds of neutrinos including from dark stars, axions, and even magnetic monopoles. These cosmic whispers offer intriguing portals into physics beyond the Standard Model, including diffuse axion background that can appear from axion star explosions, diffuse neutriono background that can appear from dark...

155. Probing Gravothermal Collapse of Dark Matter Halos: Observational Insights

Manoj Kaplinghat

25/03/2025, 15:30

I will discuss the probing of gravothermal collapse of dark matter halos through stellar streams and strong lensing systems.

31. Q-balls with an Attractive Force

Philip Lu (KIAS)

25/03/2025, 15:45

Talk

We consider the Friedberg-Lee-Sirlin Q-ball with a renormalizable cubic interaction. This attractive Yukawa interaction balances the quartic interaction and results in more compact Q-balls with a maximum stable charge. We show that our numerical simulations match our analytic calculations of the maximum charge. Additionally, we consider the fate of these unstable Q-balls with excess charge,...