2021/10/17 by Joel Karlsson, Karlsson, Joel
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2110.09885
openalex publication_date 2021/10/17 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
The landscape of possible four-dimensional low-energy effective theories\narising from compactifications of string/M-theory seems vast. This might lead\none to believe that any consistent-looking effective field theory coupled to\ngravity can be obtained as a low-energy limit of string theory. However, a set\nof "swampland" conjectures suggests that this is not true and that, in fact,\nthere is an even larger set of effective field theories that cannot be obtained\nin this way. In particular, the AdS instability swampland conjecture asserts\nthat nonsupersymmetric anti-de Sitter vacua are unstable. These swampland\ncriteria can have implications for, for instance, low-energy physics and\ncosmology.\n M-theory is a nonperturbative unification of all superstring theories. Its\nlow-energy limit, eleven-dimensional supergravity, admits two compactifications\non the squashed seven-sphere. One of the solutions has one unbroken\nsupersymmetry (\N = 1) while the other has none (\N = 0).\nDue to the AdS instability swampland conjecture, the latter should be unstable.\nHowever, this has not been demonstrated explicitly. To study the stability of\nthe \N = 0 vacuum, we investigate the mass spectrum of the theory.\nThe main advancement compared to previous attempts is the realisation that all\nmass operators in the Freund-Rubin compactification are related to a universal\nLaplacian, allowing us to relate Weyl tensor terms to group invariants. One\nlimitation of the group-theoretical method we employ is that it can lead to\nfalse roots. This is remedied, at least in part, by demanding that the fields\nform supermultiplets in the \N = 1 case. Although we arrive at an\neigenvalue spectrum for all operators of interest, there is a hint that the\nresults may be incomplete. Thus, we do not reach a decisive conclusion\nregarding the investigated type of instability.\n