摘要:

We study spatially localized solutions to the n-dimensional wave equation utt= [c(x)]2δ u, where c(x) = c1Xx1>0(X) + c2Xxb>0(X), Explicit formulas are obtained for pulses which are approximate solutions to the wave equation. These approximate solutions are asymptotic to exact solutions in the high frequency limit in the sense that the energy of the error term tends to zero as the frequency tends to infinity.

ISSN:0041-1450    

DOI:10.1080/00411458508211692

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A use is demonstrated for aparabolic operator in the context of the context of the existence theory problem of te Vlasov-Poisson system. It is shown that some aspects of the evolution of the field can be viewed as a diffusion porcess and that relevant estimates on the field can be derived through the use of the heat operator. The application of this to the existence theory problem is demonstrated.

ISSN:0041-1450    

DOI:10.1080/00411458508211693

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The linearized Vlasov-Maxwell equations, describing longitudinal plasma waves, are studied with the addition of a simple short-range collision term and for a given equilibrium distribution. The problem of stability, and of existence and location of isolated eigenvalues determining the asymptotic time behavior of the plasma following a small plane wave initial perturbation with given arbitrary wave number are investigated.

ISSN:0041-1450    

DOI:10.1080/00411458508211694

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Neutron diffusion in a uniform convex body is considered, and the time-independent distribution sought from the integral version of the Boltzmann equation. After the general properties of the scattering operator [Kcirc] are listed, the integral transport operator Ĝ[Kcirc] is investiated in the space C of bounded continuous functions, in the dual space C†(containing the measures), as well as in appropriate1 weighted L2and L1—spaces. For a nonabsorbing medium the norm ‖Ĝ[Kcirc]‖ turns out to be equal to 1 in C-space, but may exceed that bound in the other three spaces. On the other hand, the spectral radius spr(Ĝ[Kcirc]) is shown to be smaller than 1 in the C and L1—spaces, which assures the convergence of iterative solutions in both topologies. The operator ĜĴĜ[Kcirc], where Ĵ reverses the neutron velocity, is selfadjoint in L2, which is useful in a variational method.

ISSN:0041-1450    

DOI:10.1080/00411458508211695

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

We consider random fluctuations in the velocity of a molecule which is subjeclted to laser radiation. Three cases are treated, each applicable to a proposed method of isotope separation. In the first case, an exact solution is found for the velocity distribution using combinatorial methods. In the second and third cases. approximate solutions are obtained.

ISSN:0041-1450    

DOI:10.1080/00411458508211696

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The relation between the spectra of the linear transport operator and the C0-semigroup generated by it is studied by means of a spectral mapping theorem for the exponential function for positive operators on Banach lattices.

ISSN:0041-1450    

DOI:10.1080/00411458508211697

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

It is sugested that in certain cases the Fredholm alernativ theorem can be-used to simplify existence proofs in time-independent linear transport theory. Existing results in abstract kinetic equations theory are generalized as to encompass polarized light transfer as well as certain inhomogeneous finite slab media.

ISSN:0041-1450    

DOI:10.1080/00411458508211698

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

by A.M. Berthier, Pitman Publishing Inc., MA, 1982, 256 pp. ISBN 0273 08562X.

ISSN:0041-1450    

DOI:10.1080/00411458508211699

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor