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A Non-degenerate Scattering Theory for the Wave Equation on Extremal Reissner-Nordström.

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Angelopoulos, Yannis 
Aretakis, Stefanos 


It is known that sub-extremal black hole backgrounds do not admit a (bijective) non-degenerate scattering theory in the exterior region due to the fact that the redshift effect at the event horizon acts as an unstable blueshift mechanism in the backwards direction in time. In the extremal case, however, the redshift effect degenerates and hence yields a much milder blueshift effect when viewed in the backwards direction. In this paper, we construct a definitive (bijective) non-degenerate scattering theory for the wave equation on extremal Reissner-Nordström backgrounds. We make use of physical-space energy norms which are non-degenerate both at the event horizon and at null infinity. As an application of our theory we present a construction of a large class of smooth, exponentially decaying modes. We also derive scattering results in the black hole interior region.


Funder: Alfred P. Sloan Foundation; doi:


math.AP, math.AP, gr-qc

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Commun Math Phys

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Springer Science and Business Media LLC
Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada (502581)
Connaught Fund (503071)