1,105 research outputs found
On rational boundary conditions for higher-order long-wave models
Higher-order corrections to classical long-wave theories enable simple and efficient modelling of the onset of wave dispersion and size effects produced by underlying micro-structure. Since such models feature higher spatial derivatives,
one needs to formulate additional boundary conditions when confined to bounded domains. There is a certain controversy associated with these
boundary conditions, because it does not seem possible to justify their choice by purely physical considerations. In this paper an asymptotic model for onedimensional chain of particles is chosen as an exemplary higher-order theory. We demonstrate how the presence of higher-order derivative terms results in
the existence of non-physical “extraneous” boundary layer-type solutions and argue that the additional boundary conditions should generally be formulated to eliminate the contribution of these boundary layers into the averaged solution. Several new methods of deriving additional boundary conditions are presented for essential boundary. The results are illustrated by numerical examples featuring comparisons with an exact solution for the finite chain
Asymptotic and Padé Approximants Methods in the Theory of Reinforced Plates and Shells
 
Asymptotic Investigation of the Nonlinear Dynamic Boundary Value Problem for Rods
 
Higher Order Matrix SUSY Transformations in Two-Dimensional Quantum Mechanics
The iteration procedure of supersymmetric transformations for the
two-dimensional Schroedinger operator is implemented by means of the matrix
form of factorization in terms of matrix 2x2 supercharges. Two different types
of iterations are investigated in detail. The particular case of diagonal
initial Hamiltonian is considered, and the existence of solutions is
demonstrated. Explicit examples illustrate the construction.Comment: 15
Homogenization and Perturbation Procedures in the Theory of Ring-Stiffened Shells
 
Lorentz Symmetry Breaking in Abelian Vector-Field Models with Wess-Zumino Interaction
We consider the abelian vector-field models in the presence of the
Wess-Zumino interaction with the pseudoscalar matter. The occurence of the
dynamic breaking of Lorentz symmetry at classical and one-loop level is
described for massless and massive vector fields. This phenomenon appears to be
the non-perturbative counterpart of the perturbative renormalizability and/or
unitarity breaking in the chiral gauge theories.Comment: 11 pages,LaTeX, Preprint DFUB/94 - 1
Multiparticle SUSY quantum mechanics and the representations of permutation group
The method of multidimensional SUSY Quantum Mechanics is applied to the
investigation of supersymmetrical N-particle systems on a line for the case of
separable center-of-mass motion. New decompositions of the superhamiltonian
into block-diagonal form with elementary matrix components are constructed.
Matrices of coefficients of these minimal blocks are shown to coincide with
matrices of irreducible representations of permutations group S_N, which
correspond to the Young tableaux (N-M,1^M). The connections with known
generalizations of N-particle Calogero and Sutherland models are established.Comment: 20 pages, Latex,no figure
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