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Opis: We present O(10(15)) string compactifications with the exact chiral spectrum of the standard model of particle physics. This ensemble of globally consistent F-theory compactifications automatically realizes gauge coupling unification. Utilizing the power of algebraic geometry, all global consistency conditions can be reduced to a single criterion on the base of the underlying elliptically fibered Calabi-Yau fourfolds. For toric bases, this criterion only depends on an associated polytope and is satisfied for at least O(10(15)) bases, each of which defines a distinct compactification.
Ključne besede: FLUX, F-theory, string compactifications, chiral spectrum
Objavljeno v DKUM: 23.10.2023; Ogledov: 104; Prenosov: 3
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Opis: he extremal Reissner-Nordstrom black hole admits a conformal inversion symmetry, in which the metric is mapped into itself under an inversion of the radial coordinate combined with a conformal rescaling. In the rotating generalization, Couch and Torrence showed that the Kerr- Newman metric no longer exhibits a conformal inversion symmetry, but the radial equation arising in the separation of the massless Klein-Gordon equation admits a mode-dependent inversion symmetry, where the radius of inversion depends upon the energy and azimuthal angular momentum of the mode. It was more recently shown that the static four-charge extremal black holes of STU supergravity (i.e., N = 2 supergravity in four dimension coupled to three vector multiplets) admit a generalization of the conformal inversion symmetry, in which the conformally inverted metric is a member of the same four-charge black hole family but with transformed charges. In this paper we study further generalizations of these inversion symmetries, within the general class of extremal STU supergravity black holes. For the rotating black holes, where again the massless Klein-Gordon equation is separable, we show that examples with four electric charges exhibit a generalization of the Couch-Torrence symmetry of the radial equation. Now, as in the conformal inversion of the static specializations, the inversion of the radial equation maps it to the radial equation for a rotating black hole with transformed electric charges. We also study the inversion transformations for the general case of extremal Bogomol'nyi-Prasad-Sommerfield STU black holes carrying eight charges (four electric plus four magnetic), and argue that analogous generalizations of the inversion symmetries exist for both the static and the rotating cases.
Ključne besede: black holes, supergravity, supersymmetry, conformal symmetry
Objavljeno v DKUM: 23.10.2023; Ogledov: 90; Prenosov: 4
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Opis: We present a consistency condition for 8D N 1 supergravity theories with nontrivial global structure G=Z for the non-Abelian gauge group, based on an anomaly involving the Z 1-form center symmetry. The interplay with other swampland criteria identifies the majority of 8D theories with gauge group G=Z, which have no string theory realization, as inconsistent quantum theories when coupled to gravity. While this condition is equivalent to geometric properties of elliptic K3 surfaces in F-theory compactifications, it constrains the unexplored landscape of gauge groups in other 8D string models.
Ključne besede: supergravity theories, string theory, 8D string models
Objavljeno v DKUM: 16.10.2023; Ogledov: 110; Prenosov: 3
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Opis: Motivated by the study of conserved Aretakis charges for a scalar field on the horizon of an extremal black hole, we construct the metrics for certain classes of four-dimensional and five-dimensional extremal rotating black holes in Gaussian null coordinates. We obtain these as expansions in powers of the radial coordinate, up to sufficient order to be able to compute the Aretakis charges. The metrics we consider are for 4-charge black holes in four-dimensional STU supergravity (N = 2 supergravity coupled to three vector multiplets) (including the Kerr-Newman black hole in the equal-charge case) and the general 3-charge black holes in five-dimensional STU supergravity. We also investigate the circumstances under which the Aretakis charges of an extremal black hole can be mapped by conformal inversion of the metric into Newman-Penrose charges at null infinity. We show that while this works for four-dimensional static black holes, a simple radial inversion fails in rotating cases because a necessary conformal symmetry of the massless scalar equation breaks down. We also discuss that a massless scalar field in dimensions higher than four does not have any conserved Newman-Penrose charge, even in a static asymptotically flat spacetime.
Ključne besede: supergravitiy, flat spacetime, black hole, four-dimensional rotating, metrics
Objavljeno v DKUM: 16.10.2023; Ogledov: 66; Prenosov: 7
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Opis: We argue that global F-theory compactifications to four dimensions gener- ally exhibit higher rank Yukawa matrices from multiple geometric contributions known as Yukawa points. The holomorphic couplings furthermore have large hierarchies for generic complex structure moduli. Unlike local considerations, the compact setup realizes these features all through geometry, and requires no instanton corrections. As an example, we consider a concrete toy model with SU(5) x U(1) gauge symmetry. From the geometry, we find two Yukawa points for the 10-25-4 coupling, producing a rank two Yukawa matrix. Our methods allow us to track all complex structure dependencies of the holomorphic couplings and study the ratio numerically. This reveals hierarchies of O(10(5)) and larger on a full-dimensional subspace of the moduli space.
Ključne besede: F-theory, supersymmetric effective theories
Objavljeno v DKUM: 16.10.2023; Ogledov: 64; Prenosov: 7
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