title: Instabilities in a two-dimensional polar-filament--motor system.
abstract: The dynamical interaction between filaments and motor proteins is known for their propensity to self-organize into spatio-temporal patterns. Since the filaments are polar in the sense that motors define a direction of motion on them, the system can display a spatially homogeneous polar-filament orientation. We show that the latter anisotropic state itself may become unstable with respect to inhomogeneous fluctuations. This scenario shares similarities with instabilities in planarly aligned nematic liquid crystals: in both cases the wave vector of the instability may be oriented either parallel or oblique to the polarity axis. However, the encountered instabilities here are long-wave instead of short-wave and the destabilizing modes are drifting ones due to the polar symmetry. Additionally a nonpropagating transverse instability is possible. The stability diagrams related to the various wave vector orientations relative to the polarity axis are determined and discussed for a specific model of motor-filament interactions.
authors.affiliation: Theoretische Physik, Universität Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Rühle
authors.forename: F
authors.initials: F
authors.lastname: Ziebert
authors.forename: R
authors.initials: R
authors.lastname: Peter
authors.forename: W
authors.initials: W
authors.lastname: Zimmermann
mesh_terms: D016880:Anisotropy; D050866:Liquid Crystals / Q000737:chemistry; D008840:Microfilament Proteins / Q000737:chemistry*; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry*
chemical_list: D008840:Microfilament Proteins; D020409:Molecular Motor Proteins