scholarly journals Initial Systematic Investigations of the Landscape of Low-Layer NAHE Variation Extensions

2013 ◽  
Vol 2013 ◽  
pp. 1-15
Author(s):  
Timothy Renner ◽  
Jared Greenwald ◽  
Douglas Moore ◽  
Gerald Cleaver
Keyword(s):  
Matter Content ◽  
Similar Model ◽  
Gauge Groups ◽  
Hidden Sector ◽  
String Phenomenology ◽  
Weakly Coupled ◽  
Fermionic String ◽  
Statistical Coupling ◽  
Statistical Studies ◽  
Basis Vectors

The discovery that the number of physically consistent string vacua is on the order of 10500 has prompted several statistical studies of string phenomenology. Focusing on the Weakly Coupled Free Fermionic String formalism, we present systematic extensions of a variation on the NAHE (Nanopoulos, Antoniadis, Hagelin, Ellis) set of basis vectors. This variation is more conducive to the production of “mirrored” models, in which the observable and hidden sector gauge groups (and possibly matter content) are identical. This study is parallel to the extensions of the NAHE set itself and presents statistics related to similar model properties. Statistical coupling between specific gauge groups and spacetime supersymmetry is also examined. Finally, a model with completely mirrored gauge groups is discussed. It is found that the region of the landscape explored generates no physically realistic models due to a lack of three net chiral generations.

scholarly journals PROGRESS IN WEAKLY COUPLED STRING PHENOMENOLOGY

2002 ◽  
Vol 17 (supp01) ◽  
pp. 70-83
Author(s):  
MARY K. GAILLARD
Keyword(s):  
String Theory ◽  
Supersymmetry Breaking ◽  
Particle Physics ◽  
Specific Model ◽  
Heterotic String ◽  
Particle Spectrum ◽  
Heterotic String Theory ◽  
Hidden Sector ◽  
String Phenomenology ◽  
Weakly Coupled

The weakly coupled vacuum of E8 ⊗ E8 heterotic string theory remains an attractive scenario for particle physics. The particle spectrum and the issue of dilaton stabilization are reviewed. A specific model for hidden sector condensation and supersymmetry breaking, that respects known constraints from string theory, is described, and its phenomenological and cosmological implications are discussed.

scholarly journals Classification of large N superconformal gauge theories with a dense spectrum

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Prarit Agarwal ◽  
Ki-Hong Lee ◽  
Jaewon Song
Keyword(s):  
Gauge Theories ◽  
Fixed Point Theory ◽  
Point Theory ◽  
Matter Content ◽  
Gauge Groups ◽  
Weakly Coupled ◽  
Large N ◽  
The Difference ◽  
Supersymmetric Gauge

Abstract We classify the large N limits of four-dimensional supersymmetric gauge theories with simple gauge groups that flow to superconformal fixed points. We restrict ourselves to the ones without a superpotential and with a fixed flavor symmetry. We find 35 classes in total, with 8 having a dense spectrum of chiral gauge-invariant operators. The central charges a and c for the dense theories grow linearly in N in contrast to the N2 growth for the theories with a sparse spectrum. The difference between the central charges a − c can have both signs, and it does not vanish in the large N limit for the dense theories. We find that there can be multiple bands separated by a gap, or a discrete spectrum above the band. We also find a criterion on the matter content for the fixed point theory to possess either a dense or sparse spectrum. We discover a few curious aspects regarding supersymmetric RG flows and a-maximization along the way. For all the theories with the dense spectrum, the AdS version of the Weak Gravity Conjecture (including the convex hull condition for the cases with multiple U(1)’s) holds for large enough N even though they do not have weakly-coupled gravity duals.

scholarly journals On the quantization of Seiberg-Witten geometry

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Nathan Haouzi ◽  
Jihwan Oh
Keyword(s):  
Gauge Theory ◽  
String Theory ◽  
Partition Function ◽  
Flat Space ◽  
Matter Content ◽  
Gauge Groups ◽  
Space Limit ◽  
Two Parameters ◽  
Double Quantization ◽  
Quantization Parameters

Abstract We propose a double quantization of four-dimensional $$ \mathcal{N} $$ N = 2 Seiberg-Witten geometry, for all classical gauge groups and a wide variety of matter content. This can be understood as a set of certain non-perturbative Schwinger-Dyson identities, following the program initiated by Nekrasov [1]. The construction relies on the computation of the instanton partition function of the gauge theory on the so-called Ω-background on ℝ4, in the presence of half-BPS codimension 4 defects. The two quantization parameters are identified as the two parameters of this background. The Seiberg-Witten curve of each theory is recovered in the flat space limit. Whenever possible, we motivate our construction from type IIA string theory.

scholarly journals Evaluation of the Effects of Organic Matter and Other Soil Characteristics Upon the Aggregate Stability of Some Tropical Soils

1969 ◽  
Vol 43 (4) ◽  
pp. 268-272 ◽  
Author(s):  
M. A. Lugo-López ◽  
J. Juárez, Jr.
Keyword(s):  
Organic Matter ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Tropical Soils ◽  
Development Project ◽  
Matter Content ◽  
Degree Of Stability ◽  
Statistical Studies ◽  
Level Of Significance

This paper reports on statistical studies conducted to evaluate the degree of stability of soil aggregates in terms of the respective organic-matter, clay, and silt contents of selected soils from the Lajas Valley irrigation development project. Simple regression analyses revealed that there was no correlation between aggregate stability and clay or silt content. However, a highly significant correlation was obtained when organic-matter content was considered as the independent variable. In spite of the level of significance only 16 percent of the variability in aggregate stability can be explained on a basis of the soil organic-matter content, thus limiting the possible usefulness of estimates made by using the equation developed.

scholarly journals GAUGE MODELS IN D DIMENSIONS

2013 ◽  
Vol 28 (15) ◽  
pp. 1350055 ◽  
Author(s):  
DOUGLAS MOORE ◽  
JARED GREENWALD ◽  
GERALD CLEAVER
Keyword(s):  
Large Scale ◽  
Heterotic String ◽  
Gauge Groups ◽  
Gauge Models ◽  
Baylor University ◽  
Weakly Coupled ◽  
Supersymmetric Models ◽  
String Landscape

Utilizing the gauge framework, software under development at Baylor University, we explicitly construct all layer 1 weakly coupled free fermionic heterotic string (WCFFHS) gauge models up to order 32 in four to ten large spacetime dimensions. These gauge models are well suited to large scale systematic surveys and, while they offer little phenomenologically, are useful for understanding the structure of the WCFFHS region of the string landscape. Herein, we present the gauge groups statistics for this swath of the landscape for both supersymmetric and non-supersymmetric models.

Perspective on the weakly coupled heterotic string

2015 ◽  
Vol 30 (08) ◽  
pp. 1530005 ◽  
Author(s):  
Mary K. Gaillard
Keyword(s):  
String Theory ◽  
Standard Model ◽  
Supersymmetry Breaking ◽  
Heterotic String ◽  
Particle Spectrum ◽  
Promising Candidate ◽  
Heterotic String Theory ◽  
Hidden Sector ◽  
Weakly Coupled ◽  
The Standard Model

Since the first "string revolution" of 1984, the weakly coupled E8⊗E8 heterotic string theory has been a promising candidate for the underlying theory of the Standard Model. The particle spectrum and the issue of dilaton stabilization are reviewed. Specific models for hidden sector condensation and supersymmetry breaking are described and their phenomenological and cosmological implications are discussed. The importance of T-duality is emphasized. Theoretical challenges to finding a satisfactory vacuum, as well as constraints from LHC data are addressed.

scholarly journals REDUNDANCIES IN EXPLICITLY CONSTRUCTED TEN-DIMENSIONAL HETEROTIC STRING MODELS

2011 ◽  
Vol 26 (25) ◽  
pp. 4451-4473 ◽  
Author(s):  
TIMOTHY RENNER ◽  
JARED GREENWALD ◽  
DOUGLAS MOORE ◽  
GERALD CLEAVER
Keyword(s):  
Construction Method ◽  
Space Time ◽  
Heterotic String ◽  
Large Space ◽  
Weakly Coupled ◽  
Level 1 ◽  
String Models ◽  
Basis Vectors

Using Baylor University's C ++ software for construction of weakly coupled free fermionic heterotic string models, called the FF Framework, we explicitly construct the level-1 Kač–Moody ten-dimensional heterotic string models with the aim of understanding the redundancies endemic to this construction method. We show that for models in any even number of large space–time dimensions with a massless left-mover and an odd ordered right-mover, the maximal number of space–time supersymmetries are present. We show that in order to produce all of the models for a given order, different basis vectors must be built; one cannot vary only the GSO coefficients. We also show that all combinations of two order-2 basis vectors do not produce the same models as all possible single order-4 basis vectors, implying the product of the orders used in a search does not necessarily determine the models built. We also show that to build all of the D = 10 level-1 models the inputs must be: sets of single order-6 basis vectors, pairs of basis vectors with orders 3 and 2, or sets of three order-2 basis vectors.

scholarly journals Automatic enhancement in 6D supergravity and F-theory models

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Nikhil Raghuram ◽  
Washington Taylor ◽  
Andrew P. Turner
Keyword(s):  
Gauge Group ◽  
Theory Model ◽  
Matter Content ◽  
Exotic Matter ◽  
Abelian Gauge ◽  
Gauge Groups ◽  
Prior Literature

Abstract We observe that in many F-theory models, tuning a specific gauge group G and matter content M under certain circumstances leads to an automatic enhancement to a larger gauge group G′ ⊃ G and matter content M′ ⊃ M. We propose that this is true for any theory G, M whenever there exists a containing theory G′, M′ that cannot be Higgsed down to G, M. We give a number of examples including non-Higgsable gauge factors, nonabelian gauge factors, abelian gauge factors, and exotic matter. In each of these cases, tuning an F-theory model with the desired features produces either an enhancement or an inconsistency, often when the associated anomaly coefficient becomes too large. This principle applies to a variety of models in the apparent 6D supergravity swampland, including some of the simplest cases with U(1) and SU(N) gauge groups and generic matter, as well as infinite families of U(1) models with higher charges presented in the prior literature, potentially ruling out all these apparent swampland theories.

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