Astrophysics Seminars

Gravity plays the central role in structure formation and evolution in astronomical scales. Despite the apparently simple inverse square law for the gravitational force in the non-relativistic regime, the dynamics of self-gravitating many-body...

Our understanding of astrophysical black holes is predicated on the Kerr solution to Einstein’s equations. A promising avenue for testing the Kerr hypothesis is to detect the shadow a black hole casts on the surrounding emission and compare its size...

I will describe the phenomenology of stellar basins: volumetric stellar emission into gravitationally bound orbits of weakly coupled particles such as axions, moduli, hidden photons, and fermions. While only a tiny fraction of the instantaneous...

The Event Horizon Telescope (EHT) collaboration has recently published the first image of the near-horizon region around the supermassive black hole at the center of our Milky Way galaxy, Sgr A*. In addition to providing new constraints on general...

Following the collision of two compact objects, an accretion disk forms and from it matter is ejected that sources the universe's heavy elements and that is observable as a kilonova. The amount of ejecta, the types of elements that form, and the...

Close binaries are the origin of many extraordinary events in the Universe, including type Ia supernovae and gravitational wave events. On the other extreme, wide binaries are easily disrupted by gravitational perturbations, making them a unique...

The identity of dark matter remains a mystery, despite decades of theorizing and detection efforts. This includes the mechanism for its primordial production, its interactions with itself or with visible matter, and the very nature of dark matter...

I will discuss how black holes can become nature's laboratories for ultralight axions. When a boson's Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into...

A key discovery from the past six decades of solar system exploration is that liquid water oceans may be a common planetary phenomenon. At least six ice-covered moons of the outer solar system present compelling evidence for subsurface oceans, and...

Galaxy surveys, which observe the positions and shapes of galaxies across large areas of the sky, can map a significant fraction of our cosmic volume. With the recent or imminent start of several next-generation projects — including LSST, Euclid...