UCLA Dark Matter 2025

Session

SESSION 5: Astrophysics and Cosmology-1 (CHAIR: Anna Nierenberg --UCM)

25 Mar 2025, 08:00

UCLA Physics and Astronomy Building 1-425

37. Dark matter and neutrinos: from the early universe to near-field cosmology

Vera Gluscevic (University of Southern California)

25/03/2025, 08:00

Talk

Cosmological observables, from the Lyman-alpha forest to Milky Way substructure, offer unique avenues for testing new physics. I will review the status of the recent early-universe and late-universe searches for the identity of dark matter and for new physics in the neutrino sector, summarizing the best current limits on scattering between dark matter and baryons and neutrino self-scattering....

211. Supermassive black holes from dark matter

Yifan Lu (UCLA)

25/03/2025, 08:15

The origin of high-redshift supermassive black holes (SMBHs) has been an intriguing mystery in astronomy and cosmology. Recent observations from James Webb Space Telescope further challenged our previous understanding about their formation mechanism. A promising solution to this problem is the direct collapse black holes from primordial metal-free clouds, which often requires stringent...

149. Simulating dark matter subhalos

Andrew Benson

25/03/2025, 08:30

Talk

Many astrophysical probes of dark matter (strong lensing, perturbations to stellar streams, abundances and structure of dwarf galaxies) are sensitive to the number and properties of dark matter subhalos. Accurate inference from observations requires reliable and versatile models of subhalo populations. I will describe our latest generation of subhalo population models, which provide fast and...

178. Constraints on dark matter properties from the JWST lensed quasar dark matter survey

Daniel Gilman

25/03/2025, 08:45

Talk

The JWST lensed quasar dark matter survey has delivered precise measurements of image flux ratios in 31 quadruply-imaged quasars. The compact emission surrounding the background AGN, which is now accessible with JWST, experiences significant perturbation from dark matter subhalos and field halos along the entire line of sight. As a result, this dataset is a powerful tool for characterizing the...

29. COZMIC: Cosmological Zoom-in Simulations with Initial Conditions Beyond CDM

Ethan Nadler (UC San Diego)

25/03/2025, 09:00

Talk

I will present COZMIC, a suite of over 100 cosmological zoom-in simulations with initial conditions beyond CDM. COZMIC spans initial conditions for warm, fuzzy, and interacting dark matter models. The shape of the linear matter power spectrum, P(k), is imprinted on the corresponding subhalo populations. Modeling this effect improves fuzzy and interacting dark matter bounds from the Milky Way...

39. Extending MeV Dark Matter Bounds with COSI

Robin Ma'ila Anthony-Petersen

25/03/2025, 09:15

Talk

Indirect dark matter detection in the MeV energy range is notably constrained by our limited observing sensitivity in this regime. The Compton Spectrometer and Imager (COSI), selected as a NASA Small Explorer satellite with an expected launch in 2027, will offer new potential to push these boundaries. COSI is a gamma-ray telescope that will survey the sky from 0.2-5 MeV with excellent energy...

138. Status and Potential for Detection of Warm Dark Matter in Structure Formation and X-ray Astronomy

Kevork Abazajian (University of California, Irvine)

25/03/2025, 09:30

Talk

At dwarf galaxy scales and smaller, the thermal and kinetic properties of dark matter influence the growth of cosmological and galactic structures. These effects are observable through various methods, including dwarf galaxy counts, the Lyman-alpha forest, and strong lensing. I will review the current constraints and evidence for a small-scale cutoff in structure formation, consistent with...