Research

My interests include many topics in theoretical cosmology, high-energy theory/phenomenology, astro-particle physics, quantum physics and quantum cosmology,  and gravity. I believe that all of these topics have an important role to play in our search for the true nature of the universe.

A large part of the work I am pursuing is centered around understanding the characteristics and behavior of the dark components of the universe, in particular dark matter (DM). The existence of DM, a mysterious form of matter that comprises approximately 85% of the mass of the universe, is well supported by many sources of evidence; however, the actual nature of DM, i.e. what it is made of, is still poorly understood. Thus, I am interested in exploring different candidates for DM, and studying the properties of these candidates to determine how they would behave. In the past I have worked on exploring the quantum nature of light scalar dark matter such as the axion. My previous work involved quantifying the rate of decoherence of macroscopic superpositions (Schrodinger-cat-like states) of light scalar dark matter which interacts with its environment solely through gravity.  

Other areas of interest to me include the rich phenomenology of axions, both as dark matter candidates and as sources for other new physics. Axions (the QCD axion, Ultra-light axions, and axion-like particles), originally proposed as a solution to the Strong CP problem of QCD,  are light scalar particles which have a range of applications in modern cosmology, astrophysics, and particle physics. I have been studying models of the QCD axion in particular, a well-motivated particle outside of the DM problem. Lately, I have worked on ways to modify the window of viable DM axion parameters to search for ways in which the axion can be the DM and a solution to other problems that arise from both theoretical motivations and observational findings. For instance, axions can account for exotic cooling processes in stars, but such axions do not automatically make good DM candidates; however, in some recent work, the introduction of additional interactions can make these axions more natural as the DM. There is more to axion phenomenology which I find interesting; for example, they can form bound objects called boson stars, which are Bose-Einstein condensates of axions (or other bosons) bound either by gravity or by attractive self-interactions.

Another interest of mine is the pursuit of a more complete understanding of the history of the universe. In recent years, the "standard" model of cosmology, known as the Lambda CDM model, has been challenged by some discrepant observations. Most notable is the so-called Hubble Tension, a disagreement between early-universe measurements (cosmic microwave background data from Planck or ACT, and others) and late-universe measurements (supernovae data from the sh0es collaboration, and others) of the present rate of the universe's expansion, the Hubble constant. The Hubble constant seems to be well-determined down to percent-level precision by each of these methods, as well as other complementary methods, but their results diagree at varying levels, up to 5 sigma. Since the cosmic microwave background data relies on cosmological models to extrapolate the value of the Hubble constant today,  a promising approach to understanding this discrepancy lies in trying to adjust the Lambda CDM model. Similar approaches can address tensions in other measurements, such as S8 Tension, a disagreement in the measurement of matter clustering in the late universe.

Yet other interests include pursuing a more complete understanding of gravity.  I also am interested in studying the dark and hidden components of the universe further. For instance,  dark non-Abelian gauge sectors can give rise to candidates for DM as well as other intersting new physics. I have also always been fascinated with theories of inflation and have had some experience researching these in the past. Inflation and other important early-universe phenoma are a big part of solidifying a complete picture of cosmology, so I would like to pursue work in these areas in the future as well.