摘要:

AbstractWe completely answer the question which positive solutions of the Emden‐Fowler equation,n>½,m>− 1,m+n>0 induce models of polytropic gas spheres of finite radius or finite mass. We continue and complete the investigation of the radius continuity of these models initiated by van den Broek and Verhulst8in connection with a numerical analysis by H

ISSN:0170-4214    

DOI:10.1002/mma.1670100502

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe local existence of classical smooth solutions to the equations of homogeneous non‐linear thermoelasticity in one space dimension is proved for the physically reasonable Dirichlet boundary conditions for both bounded and unbounded domains assuming smooth dat

ISSN:0170-4214    

DOI:10.1002/mma.1670100503

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn this paper we consider the unique continuation property for Schrödinger operators and its application for proving the non‐existence of positive eigenvalues (embedded in the continuous spectrum). We also use the estimate given by Jerison and Kenig9to prove unique continuation for higher powers of the Laplace operat

ISSN:0170-4214    

DOI:10.1002/mma.1670100504

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractWe consider the numerical solution of a class of one‐dimensional non‐compact integral equations by Galerkin and collocation methods and their iterated variants, using piecewise polynomials as basis functions. In particular, we obtain new results for the stability of the approximation methods, without any restriction on the norm of the integral operators. Furthermore, we extend results of Chandler and Graham4,6concerning error estimates and superconvergence to a more general class of operat

ISSN:0170-4214    

DOI:10.1002/mma.1670100505

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe exponential X‐ray transform arises in single photon emission computed tomography and is defined on functions on ℝnby, where μ is a constant. Approximate inversion, and inversion formulae of filtered back‐projection type are derived for this operator in all dimensions. In particular, explicit formulae are given for convolution kernels (filters)Kcorresponding to a general point spread functionEthat can be used to invert the exponential X‐ray transform via a filtered back‐projection algorithm. The results extend and refine work of Tretiak

ISSN:0170-4214    

DOI:10.1002/mma.1670100506

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn this paper we consider the non‐characteristic Cauchy problemut−a(x)uxx−b(x)ux−c(x)u= 0,x∈ (0,l),t∈I,u(0,t) = φ(t),ux(0,t) = 0,t∈I, whereI= ℝ orI= ℝ+andu(x, 0) = 0,x∈ [0,l], in the caseI= ℝ+. Assuming an a priori bound for ‖u(l,.)‖ L 2, we derive the exact Hölder type dependen

ISSN:0170-4214    

DOI:10.1002/mma.1670100507

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA cold gas is injected from two slots into a stream of hot gas. In a simple model this leads to a three‐phase two‐free‐boundary problem. We prove, using the variational theory of Alt, Caffarelli and Friedman, the existence of the classical sol

ISSN:0170-4214    

DOI:10.1002/mma.1670100508

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn this paper we investigate a certain exterior boundary value problem for the inhomogeneous Helmholtz equation. We give sufficient conditions for the unique solvability of a weak formulation of this problem and show an interior regularity result for all weak solutions. As a special case the incompresible, irrotational and stationary fluid flow around a totally immersed obstacle (submarine problem) is included.

ISSN:0170-4214    

DOI:10.1002/mma.1670100509

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

ISSN:0170-4214    

DOI:10.1002/mma.1670100501

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY