Unitarity and singular backgrounds

Nikolaos Brouzakis, Mariano Quiros

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    1 Citation (Scopus)


    We compute the graviton Kaluza-Klein spectrum on a gravity-dilaton background with a naked singularity for all possible boundary conditions at the singularity which are consistent with unitary evolution. We apply methods from nonrelativistic quantum mechanics with singular Schrödinger potentials. In general, the spectrum contains a tachyon, a sign of instability. Only for a particular boundary condition at the singularity is the spectrum free of tachyons. In this case, the lowest-lying graviton mode is massless. We argue that this result will also hold for other backgrounds with similar geometry near the curvature singularity. We complete our study with a brief discussion on radion perturbations and the Higgs mechanism on this singular background. © 2013 American Physical Society.
    Original languageEnglish
    Article number096007
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Issue number9
    Publication statusPublished - 12 Nov 2013


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