Video Lectures

We find ourselves at a pivotal era in the study of cosmology and galaxy formation. The dark energy + cold dark matter (ΛCDM) paradigm is firmly established as the default cosmological model, owing in large part to its incredible success in...

String stars, or Horowitz-Polchinski solutions, are string theory saddles with normalizable condensates of thermal-winding strings. In the past, string stars were offered as a possible description of stringy (Euclidean) black holes in asymptotically...

We used more than 25 million galaxies in the Subaru Hyper Suprime-Cam (HSC) shear catalog in the redshift range up to z~1.5 to measure weak lensing distortion effects due to large-scale structures. We used the measured weak lensing signals to...

M- and F-theory compactifications with ADE singularities give rise to non-abelian ADE gauge symmetries. The physical explanation for this phenomenon involves M2-branes wrapped on vanishing cycles. We consider an alternative approach which relies on...

Despite the remarkable success of the standard model of cosmology, the lambda CDM model, at predicting the observed structure of the universe over many scales, very little is known about the fundamental nature of its principal constituents: dark...

All large-scale structure cosmologists are faced with the question: how do we robustly extract cosmological information, such as on dark energy, gravity, and inflation, from observed tracers such as galaxies whose astrophysics is extremely complex...

The albedo of a celestial body is the fraction of incident starlight reflected by it. The study of the albedos of Solar System objects is at least a century old, at least in the Western world. As examples: Bond (1861) speculated on the near-unity...

Planets form from disks of dust and gas surrounding young stars.  As they grow, these new planets inherit their chemical composition from the surrounding material and then sculpt it through gravitational interactions to form gaps and other...

I will weave three separate threads. The first will be to describe recent and ongoing results from the Dark Energy Spectroscopic Survey. I will present the BAO results from the early DESI data, and some of the preparatory work for the Year 1 data. I...