Studies galaxy formation and evolution, dwarf galaxies, stellar populations, and spectroscopic properties of distant-universe galaxies.

Uses X-ray photoemission electron microscopy (X-PEEM) with XANES spectroscopy at synchrotron light sources to map crystal orientation and amorphous-to-crystalline transitions at ~10 nm resolution in biominerals (coral skeletons, sea urchin spines, mollusk nacre, tooth enamel).

Develops all-glass optical microresonator (microtoroid) platforms for label-free single-molecule and single-particle spectroscopy, extending single-molecule methods beyond fluorescent labels to study catalysis, protein folding, and photovoltaic materials.

Studies active galactic nuclei and supermassive black holes using reverberation-mapping and time-domain spectroscopy (e.g., SDSS).

Studies surface and interface chemistry of diamond and other materials, including the chemical functionalization and stabilization of near-surface NV and silicon-vacancy color centers used in diamond-based quantum sensors, in collaboration with the Choy group.

Directs the Wisconsin IceCube Particle Astrophysics Center (WIPAC); works on IceCube and next-generation neutrino telescope instrumentation for high-energy astroparticle physics.

Observational high-energy astrophysicist studying black hole X-ray binaries, relativistic jets, and their impact on surrounding gas using X-ray, optical, and radio observations.

Develops scalable, atomically-precise low-dimensional (2D/1D/0D) materials and heterostructures, focusing on single-photon emitters and spin defects in semiconductors for quantum sensing and molecular-based qubits.

Studies compact objects (neutron stars, white dwarfs) via precision timing measurements and uses existing and new radio arrays to explore the time-domain radio sky.

Astroparticle physicist and long-time IceCube collaborator, working on high-energy neutrino detection instrumentation and analysis at the South Pole.