Astrophysics Seminars

Clusters of galaxies are unique and powerful probes of cosmology and astrophysics, promising to provide new insights into the nature of dark energy and dark matter to the physics of galaxy formation. The study of galaxy clusters combines the...

Dark matter halos that merge with larger halos persist as subhalos, which host satellite galaxies. While subhalos are rapidly stripped of their dark mass, the compact luminous material remains intact for some time. I use a high-resolution...

I will study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard...

Although the observational evidence for cosmological inflation is growing, the physical mechanism behind it is still unknown. In part this is because inflation probably occurred at energy scales many orders of magnitude higher than that at man-made...

Magnetic activity in the Sun manifests itself as sunspot activity, flares, and reversals in the CaII H and K lines, and is believed to originate in the transition region between the convective and radiative zones. Lower- mass stars become fully...

Astronomers have exquisite observations of both galaxies (by directly imaging their stars) and of the intergalactic medium (in absorption spectra of background sources). While we know that the galactic baryons must have been accreted from the IGM...