Weakly coupled metastable graviton

Gregory Gabadadze

    Research output: Contribution to journalArticlepeer-review

    Abstract

    A graviton of a nonzero mass and decay width propagates five physical polarizations. The question of interactions of these polarizations is crucial for viability of models of massive/metastable gravity. This question is addressed in the context of the DGP model of a metastable graviton. First, we argue that the well-known breakdown of a naive perturbative expansion at a low scale is an artifact of the weak-field expansion itself. Then, we propose a different expansion-the constrained perturbation theory-in which the breakdown does not occur and the theory is perturbatively tractable all the way up to its natural ultraviolet cutoff. In this approach the couplings of the extra polarizations to matter and their self-couplings appear to be suppressed and should be neglected in measurements at subhorizon scales. The model reproduces results of General Relativity at observable distances with high accuracy, while predicting deviations from them at the present day horizon scale.

    Original languageEnglish (US)
    Article number064005
    Pages (from-to)064005-1-064005-7
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Volume70
    Issue number6
    DOIs
    StatePublished - Sep 2004

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

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