Velocity fluctuations of stochastic reaction fronts propagating into an unstable state: strongly pushed fronts

0536407 - FZÚ 2021 RIV US eng J - Článek v odborném periodiku
Khain, E. - Meerson, B. - Sasorov, Pavel
Velocity fluctuations of stochastic reaction fronts propagating into an unstable state: strongly pushed fronts.
Physical Review E. Roč. 102, č. 2 (2020), s. 1-9, č. článku 022137. ISSN 2470-0045. E-ISSN 2470-0053
Grant CEP: GA MŠMT EF15_003/0000449
Grant ostatní: OP VVV - HiFi(XE) CZ.02.1.01/0.0/0.0/15_003/0000449
Institucionální podpora: RVO:68378271
Klíčová slova: motion * branching random walk * branching Brownian motion
Obor OECD: Particles and field physics
Impakt faktor: 2.529, rok: 2020
Způsob publikování: Omezený přístup
https://doi.org/10.1103/PhysRevE.102.022137

The empirical velocity of a reaction-diffusion front, propagating into an unstable state, fluctuates because of the shot noises of the reactions and diffusion. Under certain conditions these fluctuations can be described as a diffusion process in the reference frame moving with the average velocity of the front. Here we address pushed fronts, where the front velocity in the deterministic limit is affected by higher-order reactions and is therefore larger than the linear spread velocity. For a subclass of these fronts-strongly pushed fronts-the effective diffusion constant D-f similar to 1/N of the front can be calculated, in the leading order, via a perturbation theory in 1/N << 1, where N >> 1 is the typical number of particles in the transition region. This perturbation theory, however, overestimates the contribution of a few fast particles in the leading edge of the front.
Trvalý link: http://hdl.handle.net/11104/0314179