Аннотация:
We define a stochastic lattice model for a fluctuating directed polymer
in $d\ge2$ dimensions. This model can be alternatively interpreted as
a fluctuating random path in 2 dimensions, or a one-dimensional
asymmetric simple exclusion process with $d>1$ conserved species of
particles. The deterministic large dynamics of the directed polymer
are shown to be given by a system of coupled Kardar-Parisi-Zhang
(KPZ) equations and diffusion equations. Using non-linear fluctuating
hydrodynamics and mode coupling theory we argue that stationary
fluctuations in any dimension can only be of KPZ type or diffusive.
The modes are pure in the sense that there are only subleading
couplings to other modes, thus excluding the occurrence of modified
KPZ-fluctuations or Lévy-type fluctuations which are common for
more than one conservation law. The mode-coupling matrices are shown
to satisfy the so-called trilinear condition.
This is a joint work with B. Wehefritz-Kaufmann.
Язык доклада: английский
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