This is the web page of Priyamvada (Priya) Natarajan, Professor in the Departments of Astronomy and Physics at Yale University. She is a theoretical astrophysicist interested in cosmology, gravitational lensing and black hole physics. Her research involves mapping the detailed distribution of dark matter in the universe exploiting the bending of light en-route to us from distant galaxies. In particular, she has focused on making dark matter maps of clusters of galaxies, the largest known repositories of dark matter and use them to probe the elusive nature of dark matter. Gravitational lensing by clusters can also be utilized to constrain dark energy models, including evolving ones and she has been developing the methodology and techniques to do so. Her work has demonstrated that lensing permits the use of clusters of galaxies as a unique and powerful astrophysical laboratory.
Priya is also actively engaged in deriving and understanding the mass assembly history of black holes over cosmic time. Her work pioneered the integration of black holes into the larger scheme of galaxy formation enabling the demographic modeling of black hole populations and their host galaxies over cosmic time. She proposed a new channel for the formation of the first black holes and is engaged in exploring its observational consequences at high and low redshift. This channel produces massive initial seed black holes derived from the direct collapse of pre-galactic gas disks at the earliest epochs. This is in contrast to the conventional picture wherein light seeds are produced from the end state of the first stars. Current measurements of the masses of black holes hosted in nearby faint galaxies supports the existence of a massive seeding model. In earlier work, she argued for the existence of an upper limit to black hole masses in the universe by showing that black holes eventually stunt their own growth. This self-regulation implies the presence of ultra-massive black holes with capped masses in the centers of nearby galaxies that have since been observationally detected.