16 research outputs found
Nonequilibrium transport through quantum-wire junctions and boundary defects for free massless bosonic fields
We consider a model of quantum-wire junctions where the latter are described
by conformal-invariant boundary conditions of the simplest type in the
multicomponent compactified massless scalar free field theory representing the
bosonized Luttinger liquids in the bulk of wires. The boundary conditions
result in the scattering of charges across the junction with nontrivial
reflection and transmission amplitudes. The equilibrium state of such a system,
corresponding to inverse temperature and electric potential , is
explicitly constructed both for finite and for semi-infinite wires. In the
latter case, a stationary nonequilibrium state describing the wires kept at
different temperatures and potentials may be also constructed. The main result
of the present paper is the calculation of the full counting statistics (FCS)
of the charge and energy transfers through the junction in a nonequilibrium
situation. Explicit expressions are worked out for the generating function of
FCS and its large-deviations asymptotics. For the purely transmitting case they
coincide with those obtained in the litterature, but numerous cases of
junctions with transmission and reflection are also covered. The large
deviations rate function of FCS for charge and energy transfers is shown to
satisfy the fluctuation relations and the expressions for FCS obtained here are
compared with the Levitov-Lesovic formulae.Comment: 50 pages, 24 figure
WZW branes and gerbes
We reconsider the role that bundle gerbes play in the formulation of the WZW
model on closed and open surfaces. In particular, we show how an analysis of
bundle gerbes on groups covered by SU(N) permits to determine the spectrum of
symmetric branes in the boundary version of the WZW model with such groups as
the target. We also describe a simple relation between the open string
amplitudes in the WZW models based on simply connected groups and in their
simple-current orbifolds.Comment: latex, 4 figures incorporate
Refined Second Law of Thermodynamics for fast random processes
We establish a refined version of the Second Law of Thermodynamics for
Langevin stochastic processes describing mesoscopic systems driven by
conservative or non-conservative forces and interacting with thermal noise. The
refinement is based on the Monge-Kantorovich optimal mass transport. General
discussion is illustrated by numerical analysis of a model for micron-size
particle manipulated by optical tweezers.Comment: 17 page
Ergodic properties of a model for turbulent dispersion of inertial particles
We study a simple stochastic differential equation that models the dispersion
of close heavy particles moving in a turbulent flow. In one and two dimensions,
the model is closely related to the one-dimensional stationary Schroedinger
equation in a random delta-correlated potential. The ergodic properties of the
dispersion process are investigated by proving that its generator is
hypoelliptic and using control theory
Large deviations of energy transfers in nonequilibrium CFT and asymptotics of non-local Riemann–Hilbert problems
International audienc
Multifractal Clustering in Compressible Flows
International audienceA quantitative relationship is found between the multifractal properties of the asymptotic mass distribution in a random dissipative system and the long-time fluctuations of the local stretching rates of the dynamics. It captures analytically the fine aspects of the strongly intermittent clustering of dynamical trajectories. Applied to a simple compressible hydrodynamical model with known stretching-rate statistics, the relation produces a nontrivial spectrum of multifractal dimensions that is confirmed numerically