Research
Dark Matter Substructure: A Lensing Perspective
Measuring the low-mass end of the dark matter halo mass function is a long-standing problem in cosmology, as it serves as a potential probe into the particle nature of dark matter. However, in anomalous flux ratio constraints on dark matter, the shape of the low end of the subhalo mass function is degenerate with the total normalization. Developing informed priors is difficult, however, as existing N-body simulations suffer from numerical issues and may undercount the number of halos. I orchestrated and analyzed large-scale suites of the semi-analytic galaxy formation model, Galacticus, to quantify key theoretical uncertainties in the population-level statistics of subhalos in simulated lensing galaxies. Implementing the informed priors from my work increased the constraining power of anomalous flux ratio studies by a factor of \( \sim 2 \).
T1DES (Tidal 1D Evolution of Subhalos) in SIDM
Self-interacting dark matter (SIDM) halos in the core-collapse regime present an intriguing solution to the anomalously dense halos found by some strong gravitational lensing observations. However, simulating dark matter satellites in these models can be prohibitively expensive. I am leading the development of the T1DES framework — a novel class of SIDM satellite halo simulations that are 1000x faster than traditional methods, all while including accurate tidal physics — enabling previously infeasible population-level studies.
Galaxy Evolution Visualized
My work focuses on using Galacticus to simulate the evolution of dark matter halos and our galaxies. However, sometimes it is hard to imagine what these simulations really look like. Here, you can watch and explore as a simulated galaxy grows and evolves over the age of the Universe. Try toggling "Galaxies only" to see what it would look like if we were to see it through a telescope, or choose "Dark matter only" to visualize the invisible structures that hold it all together. You can pause the simulation and hover over components to learn more!
Drag to rotate, scroll to zoom. Data is a static export of a single Galacticus tree from my dark-matter substructure simulations. Top 50 subhalos by infall mass are shown.