Now showing items 1-5 of 5
A note on best approximation and invertibility of operators on uniformly convex Banach spaces
(Hindawi Publishing Corp, 1991-01-01)
It is shown that if X is a uniformly convex Banach space and S a bounded linear operator onX for which ?I-S?=1, then S is invertible if and only if ?I-12S? <1. From this it follows thatif S is invertible on X then either ...
(AIP Publishing, 1991-08)
It is shown that at nonzero temperature it is possible that anomalies in representations of symmetry groups and gauge groups, present at zero temperature, disappear. Several examples are given. Thus the idea that anomalies ...
the Riemann-Hilbert problem for nonsymmetric systems
(AIP Publishing, 1991-12)
A comparison of the Riemann-Hilbert problem and the Wiener-Hopf factorization problem arising in the solution of half-space singular integral equations is presented. Emphasis is on the factorization of functions lacking ...
Inverse scattering on the line for a Dirac system
(AIP Publishing, 1991-11)
The whole-line version of the Gelfand-Levitan-Marchenko (GLM) equation for a Dirac system is studied. A new derivation of the GLM equation is given, under weaker hypotheses than Frolov's earlier treatment [Sov. Math. Dok1. ...
asymptotic-behavior of Jost functions near resonance points for Wigner-Vonneumann type potentials
(AIP Publishing, 1991-01)
In this work are considered radial Schrodinger operators - psi" + V(r)-psi = E-psi, where V(r) = a sin br/r + W(r) with W(r) bounded, W(r) = O(r-2) at infinity (a,b real). The asymptotic behavior of the Jost function and ...