MIDIT OFD CATS Modelling, Nonlinear Dynamics Optics and Fluid Dynamics Chaos and Turbulence Studies and Irreversible Thermodynamics Risø National Laboratory Niels Bohr Institute and Technical University of Denmark Building 128 Department of Chemistry Building 321 P.O. Box 49 University of Copenhagen DK-2800 Lyngby DK-4000 Roskilde DK-2100 Copenhagen Ø Denmark Denmark Denmark
by O.A. Mornev
Institute of Theoretical and
Experimental Biophysics
142292 Pushchino, Russia
MIDIT-seminar 447
Thursday April 22, 1999, 15.15 h
at MIDIT, IMM Building 305, room 027
Abstract: According to the existing paradigm, nonlinear media are divided in two classes with opposite properties - conservative media characterized by preservation of stored energy, and active excitable media where dissipation is significant. Differencies between these two classes are exposed, particularly, by that solitonts in conservative media escape interactions undestroyed, while nonlinear pulses in excitable media are annihilated upon collisions. In this talk essentialy new regimes of nonlinear pulse interaction are consedered, which were revealed recently at numerical simulation of qualitative mathematical models of excitable media. These regimes, called soliton-like, demonstrate reflection of excitation pulses upon collisions to each other and non-conductive obstacles (echo). Echo-effects in one- and two-dimantional excitable media, their mechanisms and emerging mathematical problems are discussed.