A supersonic relative velocity between dark matter (DM) and baryons--the stream velocity--at the time of recombination induces the formation of low-mass objects with anomalous properties in the early universe. We investigate objects we term Dark Matter + Gas Halos Offset by Streaming (DM GHOSts)--diffuse, DM-enriched structures formed because of a physical offset between the centers of mass of...
The Large Magellanic Cloud (LMC) can impact the dark matter halo of the Milky Way, and boost the dark matter velocity distribution in the Solar neighborhood. Cosmological simulations that sample potential Milky Way formation histories are powerful tools, which can be used to characterize the signatures of the LMC’s interaction with the Milky Way, and can provide crucial insight on the LMC’s...
In the age of gravitational wave astronomy and direct black hole imaging, the possibility that some of the black holes in the universe have a primordial, rather than stellar origin, and that they might be a non-negligible fraction of the cosmological dark matter, is quite intriguing. I will review the status of the field, and comment on search strategies and future prospects for detection...
Cosmological observables, from the CMB anisotropy to the census of galaxies in the early and local universe, offer the most direct and broad tests for the nature of dark matter, including a number of scenarios that are challenging or even impossible to test in a laboratory setting. I will review the status of the recent early-universe and late-universe searches for the identity of dark matter,...
I will discuss recent work on self-interacting dark matter in light of the latest observations and numerical simulations. In particular, I will highlight novel signatures of gravothermal collapse of dark matter halos, a unique prediction if dark matter has strong self-interactions.
One of the frontiers for advancing what is known about dark matter lies in using strong gravitational lenses to characterize the population of the smallest dark matter halos. There is a large volume of information in strong gravitational lens images so the question we seek to answer is to what extent we can refine this information. To this end, I will discuss recent forecasts of the...
In the standard model of structure formation (i.e., ΛCDM), large relative velocities between baryons and dark matter are predicted at the time of recombination. These velocities cause the formation of Supersonically Induced Gas Objects, or SIGOs. SIGOs are a natural consequence of ΛCDM structure formation. In particular, they are characterized by low dark matter abundances and metallicities,...
Dark Stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from Dark Matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. The relevant types of dark matter for heating the stars include Weakly Interacting Massive Particles (WIMPs), and Self Interacting Dark Matter (SIDM)....
I present dark matter indirect detection predictions (J-factors) for the Galactic-center using 12 highly-resolved, hydrodynamic FIRE-2 zoom cosmological simulations of Milky Way size galaxies. In addition to velocity-independent (s-wave) annihilation cross-sections ⟨σv⟩, we also calculate effective J-factors for velocity-dependent models, where the annihilation cross-section is either p-wave...
The properties of dark matter halos and subhalos on scales below 10^9 solar masses depend on the formation mechanism, mass, and possible interactions of the dark matter particle. As such, inferences of the halo mass function and the internal structure of dark halos on these scales can be interpreted in the context of fundamental dark matter physics. I will discuss how effects such as...
