Ashvin Vishwanath is a condensed matter theorist, known for his work on the gauge theory description of “beyond-Landau” quantum phase transitions, as well as the theoretical prediction of Fermi-arc surface states in Weyl semimetals. He has contributed to the theory of topological phases, in particular highlighting the special properties of defects such as dislocation and the role of crystal symmeties in protecting and diagnosing topological states. He, along with T. Senthil, introduced the concept of surface topological order and with Chen and Fidkowski used it to demonstrate the interaction reduction of 3D topological superconductors. These ideas led to his recent work on dualities between quantum field theories and their physical signatures.