4,330 research outputs found
Momentum Regularity and Stability of the Relativistic Vlasov-Maxwell-Boltzmann System
In the study of solutions to the relativistic Boltzmann equation, their
regularity with respect to the momentum variables has been an outstanding
question, even local in time, due to the initially unexpected growth in the
post-collisional momentum variables which was discovered in 1991 by Glassey &
Strauss \cite{MR1105532}. We establish momentum regularity within energy spaces
via a new splitting technique and interplay between the Glassey-Strauss frame
and the center of mass frame of the relativistic collision operator. In a
periodic box, these new momentum regularity estimates lead to a proof of global
existence of classical solutions to the two-species relativistic
Vlasov-Boltzmann-Maxwell system for charged particles near Maxwellian with hard
ball interaction.Comment: 23 pages; made revisions which were suggested by the referee; to
appear in Comm. Math. Phy
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
Spectral gap and coercivity estimates for linearized Boltzmann collision operators without angular cutoff
In this paper we prove new constructive coercivity estimates for the
Boltzmann collision operator without cutoff, that is for long-range
interactions. In particular we give a generalized sufficient condition for the
existence of a spectral gap which involves both the growth behavior of the
collision kernel at large relative velocities and its singular behavior at
grazing and frontal collisions. It provides in particular existence of a
spectral gap and estimates on it for interactions deriving from the hard
potentials \phi(r) = r^{-(s−1)}, or the so-called moderately
soft potentials \phi(r) = r^{−(s−1)}, , (without
angular cutoff). In particular this paper recovers (by constructive means),
improves and extends previous results of Pao [46]. We also obtain constructive
coercivity estimates for the Landau collision operator for the optimal
coercivity norm pointed out in [34] and we formulate a conjecture about a
unified necessary and sufficient condition for the existence of a spectral gap
for Boltzmann and Landau linearized collision operators.Comment: 29 page
Axisymmetric flow of ideal fluid moving in a narrow domain: a study of the axisymmetric hydrostatic Euler equations
In this article we will introduce a new model to describe the leading order
behavior of an ideal and axisymmetric fluid moving in a very narrow domain.
After providing a formal derivation of the model, we will prove the
well-posedness and provide a rigorous mathematical justification for the formal
derivation under a new sign condition. Finally, a blowup result regarding this
model will be discussed as well.Comment: 33 page
Global Strong Solutions of the Boltzmann Equation without Angular Cut-off
We prove the existence and exponential decay of global in time strong
solutions to the Boltzmann equation without any angular cut-off, i.e., for
long-range interactions. We consider perturbations of the Maxwellian
equilibrium states and include the physical cross-sections arising from an
inverse-power intermolecular potential with , and more
generally, the full range of angular singularities . These
appear to be the first unique global solutions to this fundamentally important
model, which grants a basic example where a range of geometric fractional
derivatives occur in a physical model of the natural world. Our methods provide
a new understanding of the effects of grazing collisions in the Boltzmann
theory.Comment: This file has not changed, but this work has been combined with
(arXiv:1002.3639v1), simplified and extended into a new preprint, please see
the updated version: arXiv:1011.5441v
- âŠ