Softly massive gravity

G. Gabadadze, M. Shifman

    Research output: Contribution to journalArticle

    Abstract

    Large-distance modification of gravity may be the best mechanism for solving the cosmological constant problem. A simple model of the large-distance modification-four-dimensional (4D) gravity with a hard mass term-is problematic from the theoretical standpoint. Here we discuss a different model, brane-induced gravity, that effectively introduces a soft graviton mass. We study the issues of unitarity, analyticity, and causality in this model in more than five dimensions. We show that a consistent prescription for the poles of the Green's function can be specified so that 4D unitarity is preserved. However, in certain instances 4D analyticity cannot be maintained when the theory becomes higher dimensional. As a result, one has to sacrifice 4D causality at distances of the order of the present-day Hubble scale. This is a welcome feature for solving the cosmological constant problem, as was recently argued in the literature. We also show that, unlike 4D massive gravity, the model has no strona-couolinc problem at intermediate scales.

    Original languageEnglish (US)
    Article number124032
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Volume69
    Issue number12
    DOIs
    StatePublished - 2004

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    gravitation
    gravitons
    poles
    Green's functions

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

    Cite this

    Softly massive gravity. / Gabadadze, G.; Shifman, M.

    In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 69, No. 12, 124032, 2004.

    Research output: Contribution to journalArticle

    Gabadadze, G. ; Shifman, M. / Softly massive gravity. In: Physical Review D - Particles, Fields, Gravitation and Cosmology. 2004 ; Vol. 69, No. 12.
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