Active fluids

Long-ranged velocity correlations in a fluid where collisions break time-reversal symmetry.
Image taken from: Grimm, Zippelius and Fuchs (2022).

In active matter, energy is exchanged locally with the environment, so that the motion is not symmetric under time-reversal. The resulting breaking of detailed balance  is crucial for the rich phenomena in living and active matter. We study the consequences of the broken time-reversal invariance on correlations in nonequilbrium stationary states and find e.g. novel long-ranged correlations.