Ould El Hadj, M., Stratton, T. orcid.org/0000-0002-2936-5404 and Dolan, S.R. orcid.org/0000-0002-4672-6523 (2020) Scattering from compact objects: Regge poles and the complex angular momentum method. Physical Review D, 101 (10). 104035. ISSN 2470-0010
Abstract
We calculate the Regge poles of the scattering matrix for a gravitating compact body, for scalar fields and for gravitational waves in the axial sector. For a neutron-starlike body, the spectrum exhibits two distinct branches of poles, labeled surface waves and broad resonances; for ultracompact objects, the spectrum also includes a finite number of narrow resonances. We show, via a WKB analysis, that the discontinuity of the effective potential at the body’s surface determines the imaginary component of the broad-resonance poles. Next, we examine the role of Regge poles in the time-independent scattering of monochromatic planar waves. We apply complex angular momentum techniques to re-sum the partial wave series for the scattering amplitude, expressing it as a residue series evaluated at poles in the first quadrant, accompanied by a background integral. We compute the scattering cross section at several frequencies, and show precise agreement with the partial-wave calculations. Finally, we show that compact bodies naturally give rise to orbiting, glory, and rainbow-scattering interference effects.
Metadata
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Copyright, Publisher and Additional Information: | © 2020 American Physical Society. Reproduced in accordance with the publisher's self-archiving policy. | ||||||
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Institution: | The University of Sheffield | ||||||
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) | ||||||
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Depositing User: | Symplectic Sheffield | ||||||
Date Deposited: | 02 Jul 2021 12:51 | ||||||
Last Modified: | 04 Jul 2021 05:47 | ||||||
Status: | Published | ||||||
Publisher: | American Physical Society (APS) | ||||||
Refereed: | Yes | ||||||
Identification Number: | https://doi.org/10.1103/physrevd.101.104035 | ||||||
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