1. Quadrillion F-theory compactifications with the exact chiral spectrum of the standard modelMirjam Cvetič, James Halverson, Ling Lin, Mingqiang Liu, Jianjun Paul Tian, 2019, izvirni znanstveni članek 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: 388; Prenosov: 11 Celotno besedilo (184,32 KB) Gradivo ima več datotek! Več... |
2. Constraints on standard model constructions in F-theoryMirjam Cvetič, James Halverson, Ling Lin, Cody Long, 2020, izvirni znanstveni članek Opis: We argue that the following three statements cannot all be true: (i) our vacuum is a type IIB/F-theory vacuum at moderate to large h(1,1); (ii) the alpha' expansion is controlled via the supergravity approximation, a la the Kachru-Kallosh-Linde-Trivedi and Large Volume scenarios; and (iii) there are no additional gauged sectors from 7-branes. Since nearly all known globally consistent F-theory models with the exact chiral spectrum of the Standard Model and gauge coupling unification occur at moderate h(1,1), this finding calls for new moduli stabilization scenarios or/and a rich 7-brane dark sector. Ključne besede: brane worlds, compactification, string theory Objavljeno v DKUM: 23.10.2023; Ogledov: 369; Prenosov: 11 Celotno besedilo (292,32 KB) Gradivo ima več datotek! Več... |
3. Generalized Couch-Torrence symmetry for rotating extremal black holes in maximal supergravityMirjam Cvetič, Christopher N. Pope, Aritra Saha, 2020, izvirni znanstveni članek 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: 400; Prenosov: 4 Celotno besedilo (287,15 KB) Gradivo ima več datotek! Več... |
4. Geometric unification of Higgs bundle vacuaMirjam Cvetič, Jonathan J. Heckman, Thomas B. Rochais, Ethan Torres, Gianluca Zoccarato, 2020, izvirni znanstveni članek Opis: Higgs bundles are a central tool used to study a range of intersecting brane systems in string compactifications. Solutions to the internal gauge theory equations of motion for the corresponding worldvolume theories of brans give rise to different low energy effective field theories. This has been heavily used in the study of M-theory on local G(2) spaces and F-theory on local elliptically fibered CalabiYau fourfolds. In this paper we show that the 3D N = 1 effective field theory defined by M-theory on a local spin(7) space unifies the Higgs bundle data associated with 4D N = 1 M- and F-theory vacua. This 3D system appears as an interface with finite thickness between different 4D vacua. We develop the general formalism of M-theory on such local spin(7) spaces and build explicit interpolating solutions. This provides a complementary local gauge theory analysis of a recently proposed approach to constructing spin(7) spaces from generalized connected sums. Ključne besede: F-theory, Higgs, M-theory, field theories, spin spices Objavljeno v DKUM: 23.10.2023; Ogledov: 376; Prenosov: 11 Celotno besedilo (1,06 MB) Gradivo ima več datotek! Več... |
5. String Universality and Non-Simply-Connected Gauge Groups in 8DMirjam Cvetič, Markus Dierigl, Ling Lin, Hao Y. Zhang, 2020, izvirni znanstveni članek 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: 441; Prenosov: 15 Celotno besedilo (207,17 KB) Gradivo ima več datotek! Več... |
6. Gaussian null coordinates for rotating charged black holes and conserved chargesMirjam Cvetič, Christopher N. Pope, Aritra Saha, Alejandro Satz, 2020, izvirni znanstveni članek 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: 215; Prenosov: 11 Celotno besedilo (244,90 KB) Gradivo ima več datotek! Več... |
7. T-branes and G(2) backgroundsRodrigo Barbosa, Mirjam Cvetič, Jonathan J. Heckman, Craig Lawrie, Ethan Torres, Gianluca Zoccarato, 2020, izvirni znanstveni članek Opis: Compactification of M-string theory on manifolds with G(2) structure yields a wide variety of 4D and 3D physical theories. We analyze the local geometry of such compactifications as captured by a gauge theory obtained from a three-manifold of ADE singularities. Generic gauge theory solutions include a nontrivial gauge field flux as well as normal deformations to the three-manifold captured by noncommuting matrix coordinates, a signal of T-brane phenomena. Solutions of the 3D gauge theory on a three-manifold are given by a deformation of the Hitchin system on a marked Riemann surface which is fibered over an interval. We present explicit examples of such backgrounds as well as the profile of the corresponding zero modes for localized chiral matter. We also provide a purely algebraic prescription for characterizing localized matter for such T-brane configurations. The geometric interpretation of this gauge theory description provides a generalization of twisted connected sums with codimension seven singularities at localized regions of the geometry. It also indicates that geometric codimension six singularities can sometimes support 4D chiral matter due to physical structure "hidden" in T-branes. Ključne besede: Yang-Mills connections, spin(7), holonomy, bundles, metrics Objavljeno v DKUM: 16.10.2023; Ogledov: 184; Prenosov: 12 Celotno besedilo (710,65 KB) Gradivo ima več datotek! Več... |
8. Yukawa hierarchies in global F-theory modelsMirjam Cvetič, Ling Lin, Mingqiang Liu, Hao Y. Zhang, Gianluca Zoccarato, 2020, izvirni znanstveni članek 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: 169; Prenosov: 11 Celotno besedilo (930,60 KB) Gradivo ima več datotek! Več... |
9. Conformal symmetries for extremal black holes with general asymptotic scalars in STU supergravityMirjam Cvetič, Christopher N. Pope, Aritra Saha, 2021, izvirni znanstveni članek Opis: We present a construction of the most general BPS black holes of STU supergravity (N = 2 supersymmetric D = 4 supergravity coupled to three vector supermultiplets) with arbitrary asymptotic values of the scalar fields. These solutions are obtained by acting with a subset of the global symmetry generators on STU BPS black holes with zero values of the asymptotic scalars, both in the U-duality and the heterotic frame. The solutions are parameterized by fourteen parameters: four electric and four magnetic charges, and the asymptotic values of the six scalar fields. We also present BPS black hole solutions of a consistently truncated STU supergravity, which are parameterized by two electric and two magnetic charges and two scalar fields. These latter solutions are significantly simplified, and are very suitable for further explicit studies. We also explore a conformal inversion symmetry of the Couch-Torrence type, which maps any member of the fourteen-parameter family of BPS black holes to another member of the family. Furthermore, these solutions are expected to be valuable in the studies of various swampland conjectures in the moduli space of string compactifications. Ključne besede: black holes, extended supersymmetry, supergravity models, string theory Objavljeno v DKUM: 16.10.2023; Ogledov: 227; Prenosov: 12 Celotno besedilo (636,89 KB) Gradivo ima več datotek! Več... |
10. Root bundles and towards exact matter spectra of F-theory MSSMsMartin Bies, Mirjam Cvetič, Ron Donagi, Mingqiang Liu, Marielle Ong, 2021, izvirni znanstveni članek Opis: Motivated by the appearance of fractional powers of line bundles in studies of vector-like spectra in 4d F-theory compactifications, we analyze the structure and origin of these bundles. Fractional powers of line bundles are also known as root bundles and can be thought of as generalizations of spin bundles. We explain how these root bundles are linked to inequivalent F-theory gauge potentials of a G(4)-flux. While this observation is interesting in its own right, it is particularly valuable for F-theory Standard Model constructions. In aiming for MSSMs, it is desired to argue for the absence of vector-like exotics. We work out the root bundle constraints on all matter curves in the largest class of currently-known F-theory Standard Model constructions without chiral exotics and gauge coupling unification. On each matter curve, we conduct a systematic "bottom"-analysis of all solutions to the root bundle constraints and all spin bundles. Thereby, we derive a lower bound for the number of combinations of root bundles and spin bundles whose cohomologies satisfy the physical demand of absence of vector-like pairs. On a technical level, this systematic study is achieved by a well-known diagrammatic description of root bundles on nodal curves. We extend this description by a counting procedure, which determines the cohomologies of so-called limit root bundles on full blow-ups of nodal curves. By use of deformation theory, these results constrain the vector-like spectra on the smooth matter curves in the actual F-theory geometry. Ključne besede: F-theory, differential geometry, algebraic geometry Objavljeno v DKUM: 16.10.2023; Ogledov: 228; Prenosov: 15 Celotno besedilo (979,06 KB) Gradivo ima več datotek! Več... |