Kaustav Mitra

I am Kaustav Mitra, a postdoc at Argonne National Lab, working with Dr. Andrew P. Hearin.

Previously, during my Ph.D. at Yale University I worked with Dr. Frank C van den Bosch on modelling the fully nonlinear scales in redshift surveys to constrain galaxy halo connection [1, 2], baryonic modelling [3] for satellite galaxy kinematics analyses, cosmological parameter inference [4] using the smallest-scale information, and stellar-to-halo mass relation in the dwarf regime [5].

Before that, I completed my B.Sc. and M.Sc. in Physics from Presidency University, Kolkata (India), during which I worked on halo occupation distributions of quasars [6], and developed a semi-analytic emission model with leptonic shock propagation and radiative transfer in blazar jets to simulate multi-wavelength blazar lightcurves from radio to gamma rays [7, 8, 9, 10].

Currently as a postdoc at Argonne, I have been leading the following projects:

1. I work on the development and calibration of empirical forward-model of galaxy formation, called Diffsky. I use it to jointly fit multi-wavelength multi-survey data to constrain galaxy formation physics. As a natural consequence, we can then use the calibrated model to generate very realistic mock galaxy catalogues for testing and validation of analyses pipelines in modern large surveys like Rubin, Roman, DESI, etc.
2. I am developing Diffmetal, a physics-driven evolution of galaxy metallicity and abundance ratio across cosmic time that is fully self-consistently modelled with star formation history and halo assembly history in Diffsky. This will enable realistic SED predictions with line emissions and line ratios that are self-consistently modelled with photometry.
3. I am also currently working on DESI Y3 ​“full-scale” cosmology analysis, combining small-scale clustering from DESI DR2 and weak lensing from multiple surveys (e.g., DES, HSC, KiDS). I am very interested in future cross-analyses with multiple surveys.

My overarching long-term goal is to develop unified frameworks for multi-survey joint analyses that will concurrently constrain galaxy formation physics, gas physics (ISM, CGM, ICM), as well as the fundamental properties of the Universe (cosmological parameters).