My research focuses on measurements of cosmological large-scale structure -- especially those using weak gravitational lensing, the very small perturbations in the shapes of distant source galaxies due to massive foreground galaxies/clusters. There are many useful applications of weak lensing due to the fact that it is sensitive to the full matter density projected along the line of sight, regardless of whether that matter is luminous (i.e., visible through a telescope) or not (dark matter). I am interested in applications of lensing to the study of the connection between galaxy observables and their underlying dark matter halos, of how cosmic structure grows with time (connected to dark energy), and of whether General Relativity is really the correct theory of gravity on cosmological scales. Much of this work involves combining gravitational lensing with other types of cosmological measurements.
From July 2019 - June 2021, I spent a lot of my time as the Spokesperson of the LSST Dark Energy Science Collaboration (DESC), preparing for high-accuracy and high-precision cosmology with the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). Since then, I remain an active member of the collaboration, and am the lead at CMU for the LINCC Frameworks Initiative, which is providing analysis software infrastructure for multiple LSST science cases, ranging from solar system science to cosmology.
In 2023, I spent a lot of time serving on the Particle Physics Project Prioritization Panel (P5), for which the report was released in December 2023.
I am currently serving as Head of the Department of Physics at CMU.
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