Cross-correlations for studying weak lensing systematics
My research focuses on using cross-correlations between weak gravitational lensing and multi-wavelength observations to constrain baryonic feedback effects, which is one of the biggest systematic uncertainties for Stage IV surveys. I achieved the first detection of the cross-correlation between cosmic shear and the diffuse X-ray background at 25σ significance, which provides direct constraints on how astrophysical processes redistribute gas in dark matter halos.
This work was then extended by jointly modeling X-ray and thermal Sunyaev-Zel'dovich cross-correlations with cosmic shear to simultaneously constrain the spatial distribution and thermodynamic properties of hot gas in halos.
Statistical Methods and Analysis Tools
Part of my research is to develop efficient statistical methods to handle the massive datasets from next-generation surveys like LSST and Euclid.
In my PhD, I worked on covariance matrix compression schemes that reduce computational costs by ~100× while preserving cosmological parameter constraints. In the Dark Energy Science Collaboration, I co-lead the N5K non-Limber integration challenge, a community effort to benchmark non-Limber integration methods, which is a critical numerical challenge for Stage IV surveys where traditional approximations break down on larger angular scales. I also co-authored 'The IA Guide,' a comprehensive reference that synthesizes intrinsic alignment formalisms to help researchers navigate this important weak lensing systematic.
You can check out the video we made for Cosmology Talks on the IA Guide here.
Dark Sector Physics
My research explores fundamental questions about the nature of dark matter and dark energy through both particle physics theory and Bayesian model comparison.
I investigate exotic dark matter candidates like scalar glueballs and dark photons, using thermal effective theory to predict their cosmological abundance and identify viable parameter spaces. On the observational side, I use Bayesian model selection to compare phenomenological dark energy scenarios, demonstrating how different cosmological probes can distinguish between standard ΛCDM and modified cosmologies with interacting dark sectors.