2,911 research outputs found
Global Classical Solutions of the Boltzmann Equation with Long-Range Interactions and Soft Potentials
In this work we prove global stability for the Boltzmann equation (1872) with
the physical collision kernels derived by Maxwell in 1866 for the full range of
inverse power intermolecular potentials, with . This
completes the work which we began in (arXiv:0912.0888v1). We more generally
cover collision kernels with parameters and satisfying
in arbitrary dimensions
with . Moreover, we prove rapid convergence as predicted by the
Boltzmann H-Theorem. When , we have exponential time decay
to the Maxwellian equilibrium states. When , our solutions
decay polynomially fast in time with any rate. These results are constructive.
Additionally, we prove sharp constructive upper and lower bounds for the
linearized collision operator in terms of a geometric fractional Sobolev norm;
we thus observe that a spectral gap exists only when , as
conjectured in Mouhot-Strain (2007).Comment: This file has not changed, but this work has been combined with
(arXiv:0912.0888v1), simplified and extended into a new preprint, please see
the updated version: arXiv:1011.5441v
The Vlasov-Poisson-Landau System in
For the Landau-Poisson system with Coulomb interaction in , we prove
the global existence, uniqueness, and large time convergence rates to the
Maxwellian equilibrium for solutions which start out sufficiently close.Comment: 50 page
Optimal time decay of the non cut-off Boltzmann equation in the whole space
In this paper we study the large-time behavior of perturbative classical
solutions to the hard and soft potential Boltzmann equation without the angular
cut-off assumption in the whole space \threed_x with \DgE. We use the
existence theory of global in time nearby Maxwellian solutions from
\cite{gsNonCutA,gsNonCut0}. It has been a longstanding open problem to
determine the large time decay rates for the soft potential Boltzmann equation
in the whole space, with or without the angular cut-off assumption
\cite{MR677262,MR2847536}. For perturbative initial data, we prove that
solutions converge to the global Maxwellian with the optimal large-time decay
rate of O(t^{-\frac{\Ndim}{2}+\frac{\Ndim}{2r}}) in the
L^2_\vel(L^r_x)-norm for any .Comment: 31 pages, final version to appear in KR
Hilbert Expansion from the Boltzmann equation to relativistic Fluids
We study the local-in-time hydrodynamic limit of the relativistic Boltzmann
equation using a Hilbert expansion. More specifically, we prove the existence
of local solutions to the relativistic Boltzmann equation that are nearby the
local relativistic Maxwellian constructed from a class of solutions to the
relativistic Euler equations that includes a large subclass of near-constant,
non-vacuum fluid states. In particular, for small Knudsen number, these
solutions to the relativistic Boltzmann equation have dynamics that are
effectively captured by corresponding solutions to the relativistic Euler
equations.Comment: 50 page
A variable delay integrated receiver for differential phase-shift keying optical transmission systems
An integrated variable delay receiver for DPSK optical transmission systems is presented. The device is realized in silicon-on-insulator technology and can be used to detect DPSK signals at any bit-rates between 10 and 15 Gbit/s
Analysis of a four-mirror cavity enhanced Michelson interferometer
We investigate the shot noise limited sensitivity of a four-mirror cavity
enhanced Michelson interferometer. The intention of this interferometer
topology is the reduction of thermal lensing and the impact of the
interferometers contrast although transmissive optics are used with high
circulating powers. The analytical expressions describing the light fields and
the frequency response are derived. Although the parameter space has 11
dimensions, a detailed analysis of the resonance feature gives boundary
conditions allowing systematic parameter studies
Global Newtonian limit for the Relativistic Boltzmann Equation near Vacuum
We study the Cauchy Problem for the relativistic Boltzmann equation with near
Vacuum initial data. Unique global in time "mild" solutions are obtained
uniformly in the speed of light parameter . We furthermore prove that
solutions to the relativistic Boltzmann equation converge to solutions of the
Newtonian Boltzmann equation in the limit as on arbitrary time
intervals , with convergence rate for any . This may be the first proof of unique global in time validity of the
Newtonian limit for a Kinetic equation.Comment: 35 page
Optimal time-domain combination of the two calibrated output quadratures of GEO 600
GEO 600 is an interferometric gravitational wave detector with a 600 m arm-length and which uses a dual-recycled optical configuration to give enhanced sensitivity over certain frequencies in the detection band. Due to the dual-recycling, GEO 600 has two main output signals, both of which potentially contain gravitational wave signals. These two outputs are calibrated to strain using a time-domain method. In order to simplify the analysis of the GEO 600 data set, it is desirable to combine these two calibrated outputs to form a single strain signal that has optimal signal-to-noise ratio across the detection band. This paper describes a time-domain method for doing this combination. The method presented is similar to one developed for optimally combining the outputs of two colocated gravitational wave detectors. In the scheme presented in this paper, some simplifications are made to allow its implementation using time-domain methods
Interaction of temperature and CO2 enrichment on soybean : Photosynthesis and seed yield
Seed yield and photosynthetic responses of soybean (Gtycine mnx L. Met. ,Ransom')
were studied in growth chambers at day/night temperatures of 18/12,22/16, and 26/20'C
and atmospheric CO, concentrations of 350, 6i5 and 1000 pL L-1. No seeds were produced at 18/12°C within any of the CO2 concentrations. Numbers of pods and seeds increased with increasing temperature and CO2 levels. Carbon dioxide enrichment increased seed yield of soybean grown at moderately cool temperatures. This increase was associated with an increase in net photosynthetic rate. Leaf photosynthesis
in response to CO2 enrichment increased more at 22/16°C than at 26/20°C. Increases in, temperature and CO2 levels enhanced total growth of plants but hastened senescence of leaves. The extended photosynthetic capacity at cool temperatures did not result in allocating more dry matter to developing pods. CO2 enrichment at 26/20°C resulted in greater seed yield increases than CO2 enrichment at lower temperatures
Asymptotic Stability of the Relativistic Boltzmann Equation for the Soft Potentials
In this paper it is shown that unique solutions to the relativistic Boltzmann
equation exist for all time and decay with any polynomial rate towards their
steady state relativistic Maxwellian provided that the initial data starts out
sufficiently close in . If the initial data are continuous then
so is the corresponding solution. We work in the case of a spatially periodic
box. Conditions on the collision kernel are generic in the sense of
(Dudy{\'n}ski and Ekiel-Je{\.z}ewska, Comm. Math. Phys., 1988); this resolves
the open question of global existence for the soft potentials.Comment: 64 page
- âŠ