Astrophysicist & Cosmologist
Studying the
origin
and
evolution of
our Universe.
I explore how the cosmos began, how structure formed, and what the largest maps of the sky can tell us about fundamental physics.
Cosmology, from theory to data
01 About
Finding fundamental physics in the structure of the cosmos.
I am a professor and Associate Head for the Undergraduate Program in the Department of Astronomy and Astrophysics at Penn State. I also direct the Center for Theoretical and Observational Cosmology at the Institute for Gravitation & the Cosmos.
My work connects theoretical cosmology with real observations—from the cosmic microwave background to galaxy surveys and gravitational-wave sources.
More about my pathProfessorAstronomy & Astrophysics, Penn State
DirectorCenter for Theoretical & Observational Cosmology
Professor · Part-timeKorea Institute for Advanced Study
02 Research
Questions written
across the sky.
I develop theoretical tools and statistical observables to extract the physics hidden in large-scale astronomical data.
A
Cosmic Origins
Inflation, primordial non-Gaussianity, and the earliest physical processes that seeded cosmic structure.
Early Universe BLarge-scale Structure
Galaxy clustering, perturbation theory, and new observables for understanding gravity on cosmic scales.
Theory + Data CCosmic Surveys
Mapping high-redshift galaxies with HETDEX to probe dark energy, galaxy evolution, and the expanding Universe.
HETDEX03 Recent classes
Ideas are best
explored together.
View teaching history
SITP · Summer 2026
Large-Scale Structure Observables in General Relativity
Galaxy clustering, cosmic rulers, and local tides.
Read the student notes Fall 2026 · ASTRO 545Cosmology
Physical foundations and the evolution of the Universe.
Course site Spring 2026 · ASTRO 497Astrophysics of the Dark Universe
Dark matter, dark energy, and their astronomical evidence.
Course site04 Recent work