#### Alladi Ramakrishnan Hall

#### A topological gauge theory for the entropy current

#### R Loganayagam

##### IAS, Princeton

*We focus on the question of how relativistic fluid *

dynamics should be thought of as a Wilsonian effective field theory

emerging from Schwinger-Keldysh path integrals. Taking the basic

principles of Schwinger-Keldysh formalism seriously, we are led to a

series of remarkable statements and a broad programme relating

relativistic fluid dynamics and topological sigma models. Apart from

the intrinsic interest for this programme from the non-equilibrium

field theory viewpoint, we also emphasise

its relevance to various fundamental questions in black hole physics.

Done