Biomedical subjects

H Chaté

Publications and source records attributed to H Chaté.

12 recordsLinked to original sources

PubMed2001

Critical coarsening without surface tension: the universality class of the voter model.

We show that the two-dimensional voter model, usually considered to be only a marginal coarsening system, represents a broad class of models for which phase ordering takes place without surface tension. We argue that voter-like growth is generically observed at order-disorder nonequilibrium transitions solely driven by interfacial noise between dynamically symmetric absorbing states.

Journal Article↗

PubMed2001

Active and passive particles: modeling beads in a bacterial bath.

A simple model for the motion of passive particles in a bath of active, self-propelled ones is introduced. It is argued that this approach provides the correct framework within which to cast the recent experimental results obtained by Wu and Libchaber [Phys Rev. Lett. 84, 3017 (2000)] for the diffusive properties of polystyrene beads displaced by bacteria suspended in a two-dimensional fluid film. Our results suggest that superdiffusive behavior should indeed be generically observed in the transition region marking the onset of collective motion.

Bacterial Physiological Phenomena↗

PubMed2001

Rare-event induced binding transition of heteropolymers.

Sequence heterogeneity broadens the binding transition of a polymer onto a linear or planar substrate. This effect is analyzed in a real-space renormalization group scheme designed to capture the statistics of rare events. In the strongly disordered regime, binding initiates at an exponentially rare set of "good contacts." Renormalization of the contact potential yields a Kosterlitz--Thouless-type transition in any dimension. This and other predictions are confirmed by extensive numerical simulations of a directed polymer interacting with a columnar defect.

Journal Article↗

PubMed2001