My research area is cosmology and gravitational lensing. I am interested in understanding how small fluctuations in the early universe grew to form the large-scale structure observed today. This process is tied to nonlinear gravitational clustering and the nature of dark matter and dark energy. Gravitational lensing, the shearing and magnification of light we receive from distant galaxies, is a powerful probe of these cosmological puzzles.
Lensing can produce multiple images in the strong lensing regime, amplify the light curves of stars due to microlensing, but more typically it leads to small distortions at the level of a few percent in the shapes of distant galaxies. This regime is known as weak lensing: it is used to map the mass distribution of galaxy clusters and the large-scale structure of the universe.
The properties of galaxies and their connection to the ambient dark matter is probed by imaging surveys of galaxies. These massive surveys are transforming our understanding of the extra-galactic universe. I have worked on theoretical aspects of lensing, on measurements from current surveys and forecasts for surveys planned for the coming decade. The Dark Energy Survey, LSST and SNAP are projects I am involved in.
Lensing and Cosmology at Penn
The people at Penn who work with me are: graduate students Hans Stabenau, Alex Borisov, Michelle Caler and Tsz-Yan Lam (jointly with Ravi Sheth); postdoc Jacek Guzik and research scientist Mike Jarvis. Masahiro Takada who was at Penn until 2005, is now faculty at Tohoku University, Japan, but is still a regular collaborator and visitor here. I also work with my colleagues Gary Bernstein, Ravi Sheth and with the other splendid members of the astronomy group at Penn.
Spring 2007: Physics 533: Topics in Cosmology (Graduate)
Fall 2007: Physics 503/Astro 525: Introduction to General Relativity and Cosmology (Graduate)
Spring 2008: Astro 12: Introduction to Astronomy II: Stars, Galaxies and Cosmology (Undergraduate)
With Harrison Prentice-Mott, a junior at Penn, and my colleague Mark Devlin, I have built a table-top experiment that uses custom-built optical lenses to explore gravitational lensing. Now in the lobby of the Physics Department and a must-see on your next visit to Philadelphia.
Papers on astro-ph archive
Refereed articles on ADS
A.B. Princeton University (1989)
Ph.D. MIT (1994)
At University of Pennsylvania, January, 2001-
Office: 4N10 David Rittenhouse Laboratory
Email: bjain at physics.upenn.edu
Fly HYD-BLR for Rs.499 Log on to MakeMyTrip! Check it out!