3,331 research outputs found
Classical resolution of black hole singularities via wormholes
In certain extensions of General Relativity, wormholes generated by
spherically symmetric electric fields can resolve black hole singularities
without necessarily removing curvature divergences. This is shown by studying
geodesic completeness, the behavior of time-like congruences going through the
divergent region, and by means of scattering of waves off the wormhole. This
provides an example of the logical independence between curvature divergences
and space-time singularities, concepts very often identified with each other in
the literature.ns of curvature divergences in the context of space-time
singularities.Comment: 6 pages, 4 figures; several improvements in main body and abstract;
final version to appear in Eur. Phys. J.
Exact solutions of effective-mass Schrodinger equations
We outline a general method for obtaining exact solutions of Schr\"{o}dinger
equations with a position dependent effective mass and compare the results with
those obtained within the frame of supersymmetric quantum theory. We observe
that the distinct effective mass Hamiltonians proposed in the literature in
fact describe exactly equivalent systems having identical spectra and wave
functions as far as exact solvability is concerned. This observation clarifies
the Hamiltonian dependence of the band-offset ratio for quantum wells.Comment: 16 pages article in LaTEX (uses standard article.sty). Please check
http://www1.gantep.edu.tr/~ozer/ for other studies of Nuclear Physics Group
at University of Gaziantep. To appear in Modern Physics Letters
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