Optimizing active work: Dynamical phase transitions, collective motion, and jamming

Phase Transitions and Collective Phenomena

Physics of active jamming during collective cellular motion in a monolayer.

Although collective cell motion plays an important role, for example during wound healing, embryogenesis, or cancer progression, the fundamental rules governing this motion are still not well understood, in particular at high cell density. We study here the motion of human bronchial epithelial cells within a monolayer, over long times. We observe that, as the monolayer ages, the cells slow down...

First-order dynamical phase transitions.

Recently, dynamical phase transitions have been identified based on the nonanalytic behavior of the Loschmidt echo in the thermodynamic limit [Heyl et al., Phys. Rev. Lett. 110, 135704 (2013)]. By introducing conditional probability amplitudes, we show how dynamical phase transitions can be further classified, both mathematically, and potentially in experiment. This leads to the definition of f...

Dynamical coupling during collective animal motion

The measurement of information flows within moving animal groups has recently been a topic of considerable interest, and it has become clear that the individual(s) that drive collective movement may change over time, and that such individuals may not necessarily always lead from the front. However, methods to quantify the influence of specific individuals on the behaviour of other group members...

Dynamical Phase Transitions and Spin Glasses

By measuring the distance between two configurations subjected to the same thermal noise, one observes for spin glasses three phases: a high-temperature phase (T> T 1), where the distance between the two configurations vanishes in the long-time limit; an intermediate phase (1’~< T < T,), where this distance has a nonzero limit independent of the initial distance; a low-temperature phase (T< ~‘2...