Astrophysics Seminars

After reviewing the initial patch problem for inflation, I present numerical and analytical results that allow us to investigate arbitrarily inhomogenous spacetimes, and that show that this problem is non-existent: non-trivial mathematical reasons...

For more than 20 years helioseismology, the study of solar oscillations, has provided an exquisite picture of the solar interior structure. However these oscillations, which are standing acoustic waves in the solar interior, have diminishing...

More than two decades after the discovery of the first exoplanet with radial velocity (RV) measurements, vast quantities of data exist from dedicated planet-hunting spectrographs. These spectra play an important role not only in the discovery and...

Gravitational waves provide a new window to the universe. Opening new bands in the gravitational spectrum is expected to yield a wealth of information. I will discuss a new experiment: the Mid-band Atomic Gravitational wave Interferometric Sensor...

The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin ``photon ring," which is composed of an infinite...

The prime Kepler mission provided high-precision photometric light curves for 10^5 stars continuously over 4 years. While the search for exoplanetary transits in these data was originally focused on signals with periods less than about a year...

In science and engineering many problems can be described as optimization problems. Many of these problems are somewhat vaguely defined and are best solved by clever heuristics. But also, many are very precisely defined and are best solved by...

The dynamics of circumplanetary disks (CPDs), mini disks formed around protoplanets embedded in their natal protoplanetary disks, is expected to regulate how the planets accrete solids and gas, as well as how satellite systems are formed. Previous...

Recent, remarkable images made by the EHT collaboration exhibit a ring of emission, presumably orbiting a six billion solar mass black hole. It is proposed that what is observed is not a gas torus but an extensive “ ergomagnetosphere" that connects...

The discoveries of gravitational waves from binary black hole and binary neutron star coalescences suggest these sources will be observed in large numbers by advanced detectors. Thanks to these observations, individual systems and the underlying...