Opis: We argue for the quantum-gravitational inconsistency of certain 6D N ¼ ð1; 0Þ supergravity theories, whose anomaly-free gauge algebra g and hypermultiplet spectrum M were observed by Raghuram et al. [J. High Energy Phys. 07 (2021) 048] to be realizable only as part of a larger gauge sector ðg0 ⊃ g; M0 ⊃ MÞ in F-theory. To detach any reference to a string theoretic method of construction, we utilize flavor symmetries to provide compelling reasons why the vast majority of such ðg; MÞ theories are not compatible with quantum gravity constraints, and how the “automatic enhancement” to ðg0 ; M0 Þ remedies this. In the first class of models, with g0 ¼ g ⊕ h, we show that there exists an unbroken flavor symmetry h acting on the matter M, which, if ungauged, would violate the no-global-symmetries hypothesis. This argument also applies to 1-form center symmetries, which govern the gauge group topology and massive states in representations different from those of massless states. In a second class, we find that g is incompatible with the flavor symmetry of certain supersymmetric strings that must exist by the completeness hypothesis. Ključne besede:supergravity theories, supersymmetric strings, quantum gravity constraints, Gauge theories, Higher-dimensional field theories, strings & branes, supergravity, symmetries Objavljeno v DKUM: 25.09.2023; Ogledov: 180; Prenosov: 7 Celotno besedilo (317,88 KB) Gradivo ima več datotek! Več...

Opis: We use Higgs bundles to study the 3D N = 1 vacua obtained from M-theory compactified on a local Spin(7) space given as a four-manifold M-4 of ADE singularities with further generic enhancements in the singularity type along one-dimensional subspaces. There can be strong quantum corrections to the massless degrees of freedom in the low energy effective field theory, but topologically robust quantities such as "parity" anomalies are still calculable. We show how geometric reflections of the compactification space descend to 3D reflections and discrete symmetries. The parity anomalies of the effective field theory descend from topological data of the compactification. The geometric perspective also allows us to track various perturbative and nonperturbative corrections to the 3D effective field theory. We also provide some explicit constructions of well-known 3D theories, including those which arise as edge modes of 4D topological insulators, and 3D N = 1 analogs of grand unified theories. An additional result of our analysis is that we are able to track the spectrum of extended objects and their transformations under higher-form symmetries. Ključne besede:Compactification, geometry, M-theory, quantum field theory, string theory techniques in condensed matter, strings & branes, supersymmetry, topology Objavljeno v DKUM: 25.09.2023; Ogledov: 213; Prenosov: 18 Celotno besedilo (910,15 KB) Gradivo ima več datotek! Več...

Opis: String and 5-brane junctions are shown to succinctly classify all known 8D N ¼ 1 string vacua. This requires an extension of the description for ordinary ½p; q-7-branes to consistently include O7þ planes, which then naturally encodes the dynamics of spn gauge algebras, including their p-form center symmetries. Central to this analysis are loop junctions, i.e., strings/5-branes which encircle stacks of 7-branes and O7þs. Loop junctions further signal the appearance of affine symmetries of emergent 9D descriptions at the 8D moduli space’s boundaries. Such limits reproduce all 9D string vacua, including the two disconnected rank (1,1) moduli components. Ključne besede:9D string vacua, 8D string vacua, anomalies, M-theory, Non-Abelian gauge theories, quantum gravity, string dualities, strings & branes, supergravity, Gauge symmetries Objavljeno v DKUM: 22.09.2023; Ogledov: 211; Prenosov: 16 Celotno besedilo (1,09 MB) Gradivo ima več datotek! Več...