# MLC

## Seminar

### Universality for Moving Stripes: A Hydrodynamic Theory of Polar Active Smectics

Toner, J (University of Oregon)
Tuesday 25 June 2013, 16:00-16:45

Seminar Room 1, Newton Institute

#### Abstract

We present a hydrodynamic theory of polar active smectics, by which we mean active striped systemsactive systems, both with and without number conservation. For the latter, we find quasi long-ranged smectic order in $d=2$ and long-ranged smectic order in $d=3$. In $d=2$ there is a Kosterlitz-Thouless type phase transition from the smectic phase to the ordered fluid phase driven by increasing the noise strength. For the number conserving case, we find that giant number fluctuations are greatly suppressed by the smectic order; that smectic order is long-ranged in $d=3$; and that nonlinear effects become important in $d=2$.