The high and dry desert of the Chilean Andes is a magnificent
site from which to observe the universe. The Atacama
Cosmology Telescope (ACT) made measurements of the cosmic microwave
background (CMB) from there for fifteen years, with a series
of...
The fundamental natures of dark energy and dark matter remain
two of the biggest mysteries in modern cosmology. We show that a
simple coupling between dark energy and dark matter can
simultaneously address two distinct hints at new physics
coming...
Abstract: We establish local well-posedness for
the Einstein-Euler system with a physical vacuum boundary in
spherical symmetry. Our proof relies on a new way of thinking about
Einstein’s equations in spherical symmetry that is well-adapted to
the...
Since its launch just two and a half years ago, JWST has made
multiple remarkable discoveries. I will discuss the search for ever
more distant galaxies and accreting black holes, and the
implications of these observations for our theories of...