Berlin 2024 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
SYNP: Symposium New Trends in Nonequilibrium Physics: Conservation Laws and Nonreciprocal Interactions
SYNP 1: New Trends in Nonequilibrium Physics: Conservation Laws and Nonreciprocal Interactions
SYNP 1.3: Hauptvortrag
Donnerstag, 21. März 2024, 16:00–16:30, H 0105
Non-reciprocal pattern formation of conserved fields — •Fridtjof Brauns1 and M Cristina Marchetti2 — 1Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, CA 93106, USA — 2University of California Santa Barbara, Santa Barbara, CA 93106, USA
Spatio-temporal patterns in nonlinear oscillatory and excitable media have been studied extensively in systems lacking conserved quantities. More recently, pattern formation of conserved fields has come into focus, including mass-conserving reaction--diffusion systems and viscoelastic active gels. Here, we show that models for these systems can be mapped to a common ``normal form'', a minimal non-reciprocal Cahn--Hilliard (NRCH) model, that can be seen as a spatially extended generalization of the FitzHugh--Nagumo model, providing a unifying dynamical-systems perspective. We show that this class of systems is identified by a characteristic dispersion relation, where the bands of unstable and propagating modes meet in an exceptional point at the bifurcation marking the onset of propagating structures (bands or droplets). The minimal NRCH model exhibits a surprisingly rich set of behaviors, including a new mechanism for interrupted coarsening that does not select a preferred wavelength and transversal undulations of wave fronts in two dimensions. Insight into these traveling structures is gained from the local dispersion relation at interfaces far away from the homogeneous steady state. This generalizes the mode coalescence mechanism for emergence of temporal order recently studied in non-reciprocally coupled systems without conserved fields.
Keywords: phase separation; traveling wave; interrupted coarsening; interface instability; exceptional point