摘要:

AbstractWe show that topologically expansive Lorenz maps can be described up to topological conjugacy by their kneading invariants. We also give a simple condition on pairs of symbol sequences which is satisfied if and only if that pair of sequences is the kneading invariant for some topologically expansive Lorenz map. A simple extension of the theorems to the case of expansive maps of the interval with multiple discontinuities is described.

ISSN:0010-3640    

DOI:10.1002/cpa.3160430402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0010-3640    

DOI:10.1002/cpa.3160430403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe stationary Vlasov‐Poisson boundary value problem in a spatially one‐dimensional domain is studied. The equations describe the flow of electrons in a plane diode. Existence is proved when the boundary condition (the cathode emission distribution) is a bounded function which decays super‐linearly or a Dirac mass. Uniqueness is proved for (physically realistic) boundary conditions which are decreasing functions of the velocity variable. It is shown that uniqueness does not always hold for the Dirac mass boundary condi

ISSN:0010-3640    

DOI:10.1002/cpa.3160430404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper we study the behavior of difference schemes approximating solutions with shocks of scalar conservation lawsWhen a difference scheme introduces artificial numerical diffusion, for example the Lax‐Friedrichs scheme, we experiencesmearingof the shocks, whereas when a scheme introduces numerical dispersion, for example the Lax‐Wendroff scheme, we experience oscillations which decay exponentially fast on both sides of the shock.In his dissertation. Gray Jennings studied approximation bymonotone schemes.These contain artificial viscosity and are first‐order accurate; they are known to be contractive in the sense of any lpnorm. Jennings showed existence and l1stability of traveling discrete smeared shocks for such schemes.Here we study similar questions for the Lax‐Wendroff scheme without artificial viscosity; this is a nonmonotone, second‐order accurate scheme. We prove existence of a one‐parameter family of stationary profiles. We also prove stability of these profiles for small perturbations in the sense of a suitably weighted l2norm. The proof relies on studying the linearized Lax‐We

ISSN:0010-3640    

DOI:10.1002/cpa.3160430405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0010-3640    

DOI:10.1002/cpa.3160430406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0010-3640    

DOI:10.1002/cpa.3160430401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY