scholarly journals ON GEOMETRICAL INTERPRETATION OF NON-ABELIAN FLAT DIRECTION CONSTRAINTS

2008 ◽  
Vol 23 (22) ◽  
pp. 3461-3492 ◽  
Author(s):  
G. B. CLEAVER ◽  
D. V. NANOPOULOS ◽  
J. T. PERKINS ◽  
J. W. WALKER
Keyword(s):  
Scalar Potential ◽  
String Model ◽  
Vacuum Expectation ◽  
Vacuum State ◽  
Effective Field ◽  
Geometrical Interpretation ◽  
Expectation Values ◽  
Brane Model ◽  
Yield Information ◽  
Comprehensive Classification

In order to produce a low-energy effective field theory from a string model, it is necessary to specify a vacuum state. In order that this vacuum be supersymmetric, it is well known that all field expectation values must be along so-called flat directions, leaving the F- and D-terms of the scalar potential to be zero. The situation becomes particularly interesting when one attempts to realize such directions while assigning vacuum expectation values to fields transforming under non-Abelian representations of the gauge group. Since the expectation value is now shared among multiple components of a field, satisfaction of flatness becomes an inherently geometrical problem in the group space. Furthermore, the possibility emerges that a single seemingly dangerous F-term might experience a self-cancellation among its components. The hope exists that the geometric language can provide an intuitive and immediate recognition of when the D and F conditions are simultaneously compatible, as well as a powerful tool for their comprehensive classification. This is the avenue explored in this paper, and applied to the cases of SU (2) and SO (2N), relevant respectively to previous attempts at reproducing the MSSM and the flipped SU (5) GUT. Geometrical interpretation of non-Abelian flat directions finds application to M-theory through the recent conjecture of equivalence between D-term strings and wrapped D-branes of Type II theory.1 Knowledge of the geometry of the flat direction "landscape" of a D-term string model could yield information about the dual brane model. It is hoped that the techniques encountered will be of benefit in extending the viability of the quasirealistic phenomenologies already developed.

scholarly journals MINIMAL SUPERSTRING STANDARD MODEL: A REVIEW

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 949-951 ◽  
Author(s):  
Gerald B. Cleaver
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Gauge Group ◽  
Effective Field Theory ◽  
Vacuum Expectation ◽  
Effective Field ◽  
Heterotic String ◽  
Expectation Values ◽  
String Solution

I review a heterotic-string solution in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)C × SU(2)L × U(1)Y and the SU(3)C × SU(2)L × U(1)Y - charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions of vacuum expectation values (VEVs) of fields that all produce solely the MSSM spectrum. Some of these directions only involve VEVs of non-Abelian singlet fields while others also contain VEVs of non-Abelian charged fields. The phenomenology of theses flat directions is summarized.

scholarly journals RECONSTRUCTING THE STRING FIELD VACUUM

2006 ◽  
Vol 21 (12) ◽  
pp. 2527-2540 ◽  
Author(s):  
A. ILDERTON
Keyword(s):  
Vacuum Expectation ◽  
Vacuum State ◽  
Closed String ◽  
Field Theories ◽  
Expectation Values

The vacuum state functional of both open closed string field theories may be perturbatively reconstructed from the vacuum expectation values it must generate. We give the calculation of the first tree and one loop terms explicitly.

scholarly journals Nondecoupling in multi-Higgs doublet models

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Francisco Faro ◽  
Jorge C. Romão ◽  
João P. Silva
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Higgs Doublet ◽  
Expectation Values ◽  
Special Cases

Abstract We consider models with any number of Higgs doublets and study the conditions for decoupling. We show that, under very general circumstances, all the quadratic coefficients of the scalar potential must be present, except in special cases, which include terms related to directions of vanishing vacuum expectation values. We give a few examples. Moreover, we show that the decoupling of all charged scalars implies the decoupling of all extra neutral scalars and vanishing $$\mathcal {CP}$$CP violation in scalar-pseudoscalar mixing.

scholarly journals Gopakumar-Vafa hierarchies in winding inflation and uplifts

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Federico Carta ◽  
Alessandro Mininno ◽  
Nicole Righi ◽  
Alexander Westphal
Keyword(s):  
Complete Intersection ◽  
Complex Structure ◽  
Scalar Potential ◽  
Vacuum Expectation ◽  
Side Product ◽  
Total Degree ◽  
De Sitter ◽  
Picard Number ◽  
Expectation Values ◽  
Combined Mechanism

Abstract We propose a combined mechanism to realize both winding inflation and de Sitter uplifts. We realize the necessary structure of competing terms in the scalar potential not via tuning the vacuum expectation values of the complex structure moduli, but by a hierarchy of the Gopakumar-Vafa invariants of the underlying Calabi-Yau threefold. To show that Calabi-Yau threefolds with the prescribed hierarchy actually exist, we explicitly create a database of all the genus 0 Gopakumar-Vafa invariants up to total degree 10 for all the complete intersection Calabi-Yau’s up to Picard number 9. As a side product, we also identify all the redundancies present in the CICY list, up to Picard number 13. Both databases can be accessed at this link (https://www.desy.de/∼westphal/GV_CICY_webpage/GVInvariants.html).

scholarly journals WIGHTMAN FUNCTION AND CASIMIR DENSITIES FOR ROBIN PLATES IN THE FULLING–RINDLER VACUUM

2006 ◽  
Vol 21 (11) ◽  
pp. 2353-2375 ◽  
Author(s):  
A. A. SAHARIAN ◽  
R. M. AVAGYAN ◽  
R. S. DAVTYAN
Keyword(s):  
Boundary Conditions ◽  
Coupling Parameter ◽  
Vacuum Expectation ◽  
Vacuum State ◽  
Summation Method ◽  
Wightman Function ◽  
Parallel Plates ◽  
Expectation Values ◽  
Interaction Forces ◽  
Massive Scalar Field

Wightman function, the vacuum expectation values of the field square and the energy–momentum tensor are investigated for a massive scalar field with an arbitrary curvature coupling parameter in the region between two infinite parallel plates moving by uniform proper acceleration. We assume that the field is prepared in the Fulling–Rindler vacuum state and satisfies Robin boundary conditions on the plates. The mode–summation method is used with a combination of a variant of the generalized Abel–Plana formula. This allows to extract manifestly the contributions to the expectation values due to a single boundary and to present the second plate-induced parts in terms of exponentially convergent integrals. Various limiting cases are investigated. The vacuum forces acting on the boundaries are presented as a sum of the self-action and "interaction" terms. The first one contains well-known surface divergences and needs a further renormalization. The "interaction" forces between the plates are investigated as functions of the proper accelerations and coefficients in the boundary conditions. We show that there is a region in the space of these parameters in which the "interaction" forces are repulsive for small distances and attractive for large distances.

scholarly journals Geometry of orientifold vacua and supersymmetry breaking

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Thibaut Coudarchet ◽  
Emilian Dudas ◽  
Hervé Partouche
Keyword(s):  
Field Theory ◽  
Supersymmetry Breaking ◽  
Effective Field Theory ◽  
Scalar Potential ◽  
Open String ◽  
Closed String ◽  
Effective Field ◽  
Internal Space ◽  
Gravitino Mass ◽  
The One

Abstract Starting from a peculiar orientifold projection proposed long ago by Angelantonj and Cardella, we elaborate on a novel perturbative scenario that involves only D-branes, together with the two types of orientifold planes O± and anti-orientifold planes $$ {\overline{\mathrm{O}}}_{\pm } $$ O ¯ ± . We elucidate the microscopic ingredients of such models, connecting them to a novel realization of brane supersymmetry breaking. Depending on the position of the D-branes in the internal space, supersymmetry can be broken at the string scale on branes, or alternatively only at the massive level. The main novelty of this construction is that it features no NS-NS disk tadpoles, while avoiding open-string instabilities. The one-loop potential, which depends on the positions of the D-branes, is minimized for maximally broken, non-linearly realized supersymmetry. The orientifold projection and the effective field theory description reveal a soft breaking of supersymmetry in the closed-string sector. In such models it is possible to decouple the gravitino mass from the value of the scalar potential, while avoiding brane instabilities.

Sign in / Sign up

Export Citation Format

Share Document