English

Passage of radiation through wormholes of arbitrary shape

High Energy Physics - Theory 2018-04-03 v5 High Energy Astrophysical Phenomena General Relativity and Quantum Cosmology

Abstract

We study quasinormal modes and scattering properties via calculation of the SS-matrix for scalar and electromagnetic fields propagating in the background of spherically and axially symmetric, traversable Lorentzian wormholes of a generic shape. Such wormholes are described by the Morris-Thorne ansatz and its axially symmetric generalization. The properties of quasinormal ringing and scattering are shown to be determined by the behavior of the wormhole's shape function b(r)b(r) and shift factor Φ(r)\Phi(r) near the throat. In particular, wormholes with the shape function b(r)b(r), such that b(r)1b'(r) \approx 1, have very long-lived quasinormal modes in the spectrum. We have proved that the axially symmetric traversable Lorentzian wormholes, unlike black holes and other compact rotating objects, do not allow for superradiance. As a by product we have shown that the 6th order WKB formula used for scattering problems of black or wormholes provides high accuracy and thus can be used for quite accurate calculations of the Hawking radiation processes around various black holes.

Keywords

Cite

@article{arxiv.1004.1284,
  title  = {Passage of radiation through wormholes of arbitrary shape},
  author = {R. A. Konoplya and A. Zhidenko},
  journal= {arXiv preprint arXiv:1004.1284},
  year   = {2018}
}

Comments

10 pages, 11 figures, the automatic procedure for calculations of the 6th order WKB quasinormal modes and reflection/transmission coefficients can be found on https://goo.gl/nykYGL