Large-area surveys such as Gaia have given us an unprecedented
amount of data on stars in the Milky Way. One of the largest
ongoing challenges in understanding the present-day structure and
formation history of our Galaxy (i.e. Galactic archaeology)...
Astronomical observations indicate that coherent, dynamically
important magnetic fields are ubiquitous in the Universe. However,
neither the origin problem -- what are the physical mechanisms that
generate the initial ``seed'' magnetic fields —- nor...
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...
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...
