A bright and statistically significant flux of GeV-scale gamma rays has been detected from the region surrounding the Galactic Center. While the spectrum, angular distribution, and intensity of this signal is consistent with the predictions of annihilating dark matter matter particles, it has also been suggested that these gamma rays could potentially be produced by a large population of...
I will discuss gaps in our coverage of the gravitational spectrum and possible new methods for filling them. Atom interferometry shows promise for detecting gravitational waves in the frequency range around a Hz, the “mid-band” between LIGO and LISA. Intermediate-scale atomic detectors are currently under construction. These would demonstrate the technology, paving the way for full-scale...
Axion-like fields appear in many string theory constructions. I will discuss a proposed explanation for why they are so ubiquitous: they play a crucial role in eliminating would-be global symmetries from the theory. This also gives a new perspective on axion interactions with magnetic monopoles. I will explain how magnetic monopole loops give rise to an axion potential.
The abundance of dark matter is a key piece of information that informs any fundamental theory aiming to describe its properties. However, mapping this measurement onto the parameters of the underlying theory relies on the cosmology at early times, which is itself not well-anchored by observation. I will describe a few ways in which the properties of the Universe at early times could deviate...
If even a relatively small number of primordial black holes (PBH) were created in the early universe, they will constitute an increasingly large fraction of the total energy density as space expands. It is thus well-motivated to consider scenarios in which the early universe was dominated by short lived PBH (M < 10^9 grams, t < 1 sec) whose Hawking radiation produces both the Standard Model...
The discovery of high-energy cosmic neutrinos opened a new window of astroparticle physics. Their origin is a new mystery in the field, which is tightly connected to the long-standing puzzle about the origin of cosmic rays. I will discuss theoretical implications of the latest results on high-energy neutrino and cosmic-ray observations, and demonstrate the power of multi-messenger approaches....
Line intensity mapping (LIM) is a rapidly developing new technique to study astrophysics and cosmology. With LIM, the luminosity density of a given atomic/molecular emission line is mapped in a three-dimensional volume. I will discuss how this technique can be used to determine the distribution of dark matter and to also probe specific dark-matter candidates. I will also describe how the...
I will review some recently proposed scenarios for PBH formation, as well as astrophysical consequences of dark matter in the form of primordial black holes.
