String Theory, String Model-Building, and String Phenomenology — A Practical Introduction

2008 ◽  
pp. 255-377
Author(s):  
Keith R. Dienes
Keyword(s):  
String Theory ◽  
Model Building ◽  
String Model ◽  
String Phenomenology

No-scale supergravity inflation: A bridge between string theory and particle physics?

2016 ◽  
Vol 25 (14) ◽  
pp. 1630027 ◽  
Author(s):  
John Ellis
Keyword(s):  
Supergravity Models ◽  
String Theory ◽  
Effective Potential ◽  
Particle Physics ◽  
Model Building ◽  
Inflationary Model ◽  
New Wave ◽  
Microwave Background ◽  
Supergravity Theory ◽  
Text Model

The plethora of recent and forthcoming data on the cosmic microwave background (CMB) data are stimulating a new wave of inflationary model-building. Naturalness suggests that the appropriate framework for models of inflation is supersymmetry. This should be combined with gravity in a supergravity theory, whose specific no-scale version has much to commend it, e.g. its derivation from string theory and the flat directions in its effective potential. Simple no-scale supergravity models yield predictions similar to those of the Starobinsky [Formula: see text] model, though some string-motivated versions make alternative predictions. Data are beginning to provide interesting constraints on the rate of inflaton decay into Standard Model particles. In parallel, LHC and other data provide significant constraints on no-scale supergravity models, which suggest that some sparticles might have masses close to present experimental limits.

scholarly journals IMPLICATIONS OF NONUNIVERSAL SOFT MASSES FOR GAUGE COUPLING UNIFICATION

1996 ◽  
Vol 11 (05) ◽  
pp. 903-920 ◽  
Author(s):  
RICHARD ALTENDORFER ◽  
TATSUO KOBAYASHI
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Model Building ◽  
Gauge Coupling ◽  
String Model ◽  
Gauge Couplings ◽  
Gaugino Masses

We study the gauge coupling unification of the minimal supersymmetric standard model with nonuniversal soft scalar and gaugino masses. The unification scale of the gauge couplings is estimated for nonuniversal cases. It is sensitive to the nonuniversality. It turns out that these cases can be combined with the assumption of string unification, which leads to a prediction of sin 2 θW(MZ) and k1, the normalization of the U (1)Y generator. String unification predicts that k1=1.3–1.4. These values have nontrivial implications for string model building. Two-loop corrections are also calculated. Some of these cases exhibit a large discrepancy between experiment and string unification. We calculate string threshold corrections to explain the discrepancy.

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 Geography of fields in extra dimensions: String theory lessons for particle physics

2015 ◽  
Vol 30 (10) ◽  
pp. 1530008 ◽  
Author(s):  
Hans Peter Nilles ◽  
Patrick K. S. Vaudrevange
Keyword(s):  
String Theory ◽  
Particle Physics ◽  
Extra Dimensions ◽  
Model Building ◽  
Unified Theory ◽  
Fundamental Interactions ◽  
Spatial Dimensions ◽  
Physics Model ◽  
String Theories

String theoretical ideas might be relevant for particle physics model building. Ideally one would hope to find a unified theory of all fundamental interactions. There are only a few consistent string theories in D = 10 or 11 spacetime dimensions, but a huge landscape in D = 4. We have to explore this landscape to identify models that describe the known phenomena of particle physics. Properties of compactified six spatial dimensions are crucial in that respect. We postulate some useful rules to investigate this landscape and construct realistic models. We identify common properties of the successful models and formulate lessons for further model building.

CANONICAL QUANTIZATION OF REGULARIZED STRING THEORY

1991 ◽  
Vol 06 (39) ◽  
pp. 3621-3625 ◽  
Author(s):  
S. A. FROLOV ◽  
A. A. SLAVNOV
Keyword(s):  
String Theory ◽  
Canonical Quantization ◽  
String Model ◽  
Critical Dimension ◽  
Hamiltonian Analysis

Canonical quantization of a regularized string model taking into account changes in the type of constraints is performed. It is shown that a standard Hamiltonian analysis of this model leads to a renormalization of the critical dimension obtained in Refs. 4–9 by different methods.

Resolutions of Bbb Cn/Bbb Znorbifolds, their U(1) bundles, and applications to string model building

2007 ◽  
Vol 2007 (03) ◽  
pp. 035-035 ◽  
Author(s):  
Stefan Groot Nibbelink ◽  
Michele Trapletti ◽  
Martin G.A Walter
Keyword(s):  
Model Building ◽  
String Model

scholarly journals The Expanding Zoo of Calabi-Yau Threefolds

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
Rhys Davies
Keyword(s):  
Abelian Group ◽  
String Theory ◽  
Fundamental Group ◽  
Model Building ◽  
Short Review ◽  
Heterotic String ◽  
Discrete Groups ◽  
Heterotic String Theory ◽  
Hodge Numbers ◽  
Topological Transitions

This is a short review of recent constructions of new Calabi-Yau threefolds with small Hodge numbers and/or nontrivial fundamental group, which are of particular interest for model building in the context of heterotic string theory. The two main tools are topological transitions and taking quotients by actions of discrete groups. Both of these techniques can produce new manifolds from existing ones, and they have been used to bring many new specimens to the previously sparse corner of the Calabi-Yau zoo, where both Hodge numbers are small. Two new manifolds are also obtained here from hyperconifold transitions, including the first example with fundamental groupS3, the smallest non-Abelian group.

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