Solving the simplest theory of quantum gravity

Sergei Dubovsky, Raphael Flauger, Victor Gorbenko

    Research output: Contribution to journalArticlepeer-review


    We solve what is quite likely the simplest model of quantum gravity, the worldsheet theory of an infinitely long, free bosonic string in Minkowski space. Contrary to naive expectations, this theory is non-trivial. We illustrate this by constructing its exact factorizable S-matrix. Despite its simplicity, the theory exhibits many of the salient features expected from more mature quantum gravity models, including the absence of local off-shell observables, a minimal length, as well as (integrable relatives of) black holes. All these properties follow from the exact S-matrix. We show that the complete finite volume spectrum can be reconstructed analytically from this S-matrix with the help of the thermodynamic Bethe Ansatz. We argue that considered as a UV complete relativistic 2- dimensional quantum field theory the model exhibits a new type of renormalization group flow behavior, “asymptotic fragility”. Asymptotically fragile flows do not originate from a UV fixed point.

    Original languageEnglish (US)
    Article number133
    JournalJournal of High Energy Physics
    Issue number9
    StatePublished - Sep 27 2012


    • 2D gravity
    • Bethe ansatz
    • Bosonic strings
    • Exact S-matrix

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics


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