scholarly journals HETEROTIC COSET MODELS

1995 ◽  
Vol 10 (07) ◽  
pp. 549-559 ◽  
Author(s):  
CLIFFORD V. JOHNSON
Keyword(s):  
String Theory ◽  
Heterotic String ◽  
Conformal Field Theories ◽  
Final Model ◽  
Heterotic String Theory ◽  
Conformal Field ◽  
String Compactifications ◽  
Gauge Anomalies ◽  
Coset Models ◽  
Special Case

A description is given on how to construct (0, 2) supersymmetric conformal field theories as coset models. These models may be used as non-trivial backgrounds for heterotic string theory. They are realized as a combination of an anomalously gauged Wess–Zumino–Witten model, right-moving supersymmetric fermions, and left-moving current algebra fermions. Requiring the sum of the gauge anomalies from the bosonic and fermionic sectors to cancel yields the final model. Applications discussed include exact models of extremal four-dimensional charged black holes and Taub–NUT solutions of string theory. These coset models may also be used to construct important families of (0, 2) supersymmetric heterotic string compactifications. The Kazama–Suzuki models are the left-right symmetric special case of these models.

scholarly journals Hierarchical structure of physical Yukawa couplings from matter field Kähler metric

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Keiya Ishiguro ◽  
Tatsuo Kobayashi ◽  
Hajime Otsuka
Keyword(s):  
String Theory ◽  
Hierarchical Structure ◽  
Matter Field ◽  
Heterotic String ◽  
Heterotic String Theory ◽  
Kähler Metric ◽  
Yukawa Couplings ◽  
String Compactifications ◽  
Kahler Metric ◽  
Matter Fields

Abstract We study the impacts of matter field Kähler metric on physical Yukawa couplings in string compactifications. Since the Kähler metric is non-trivial in general, the kinetic mixing of matter fields opens a new avenue for realizing a hierarchical structure of physical Yukawa couplings, even when holomorphic Yukawa couplings have the trivial structure. The hierarchical Yukawa couplings are demonstrated by couplings of pure untwisted modes on toroidal orbifolds and their resolutions in the context of heterotic string theory with standard embedding. Also, we study the hierarchical couplings among untwisted and twisted modes on resolved orbifolds.

THE SUPERBRANCH POINTS AND TWO-LOOP CORRECTION IN THE HETEROTIC STRING THEORY

1988 ◽  
Vol 03 (01) ◽  
pp. 91-108 ◽  
Author(s):  
M. Bershadsky
Keyword(s):  
String Theory ◽  
Moduli Space ◽  
Heterotic String ◽  
Total Derivative ◽  
Loop Correction ◽  
Heterotic String Theory ◽  
Gauge Groups ◽  
Spin Structures ◽  
Conformal Field ◽  
Heterotic String Theories

In this paper we discuss the notion of superbranch point. The conformal field simulating the superbranch point is constructed. Using this field we construct the two-loop correction in the heterotic string theories (for the theories with gauge groups SO (32) and E8×E8). The contribution from different spin structures cancel each other but only up to the total derivative over the moduli space.

scholarly journals Constructing Carrollian CFTs

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Nishant Gupta ◽  
Nemani V. Suryanarayana
Keyword(s):  
Scalar Fields ◽  
Higher Dimensions ◽  
Field Theories ◽  
Conformal Field Theories ◽  
Relativistic Limit ◽  
Conformal Field ◽  
Local Symmetries ◽  
Derivatives Of ◽  
Special Case

Abstract We construct classical theories for scalar fields in arbitrary Carroll spacetimes that are invariant under Carrollian diffeomorphisms and Weyl transformations. When the local symmetries are gauge fixed these theories become Carrollian conformal field theories. We show that generically there are at least two types of such theories: one in which only time derivatives of the fields appear and the other in which both space and time derivatives appear. A classification of such scalar field theories in three (and higher) dimensions up to two derivative order is provided. We show that only a special case of our theories arises in the ultra-relativistic limit of a covariant parent theory.

scholarly journals Cascade of special holonomy manifolds and heterotic string theory

2002 ◽  
Vol 622 (1-2) ◽  
pp. 3-45 ◽  
Author(s):  
Katsuyuki Sugiyama ◽  
Satoshi Yamaguchi
Keyword(s):  
String Theory ◽  
Heterotic String ◽  
Heterotic String Theory ◽  
Special Holonomy

scholarly journals Symplectic modular symmetry in heterotic string vacua: flavor, CP, and R-symmetries

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Keiya Ishiguro ◽  
Tatsuo Kobayashi ◽  
Hajime Otsuka
Keyword(s):  
String Theory ◽  
Common Origin ◽  
Heterotic String ◽  
Discrete Groups ◽  
Heterotic String Theory ◽  
Flavor Symmetries ◽  
Cp Symmetry

Abstract We examine a common origin of four-dimensional flavor, CP, and U(1)R symmetries in the context of heterotic string theory with standard embedding. We find that flavor and U(1)R symmetries are unified into the Sp(2h + 2, ℂ) modular symmetries of Calabi-Yau threefolds with h being the number of moduli fields. Together with the $$ {\mathbb{Z}}_2^{\mathrm{CP}} $$ ℤ 2 CP CP symmetry, they are enhanced to GSp(2h + 2, ℂ) ≃ Sp(2h + 2, ℂ) ⋊ $$ {\mathbb{Z}}_2^{\mathrm{CP}} $$ ℤ 2 CP generalized symplectic modular symmetry. We exemplify the S3, S4, T′, S9 non-Abelian flavor symmetries on explicit toroidal orbifolds with and without resolutions and ℤ2, S4 flavor symmetries on three-parameter examples of Calabi-Yau threefolds. Thus, non-trivial flavor symmetries appear in not only the exact orbifold limit but also a certain class of Calabi-Yau three-folds. These flavor symmetries are further enlarged to non-Abelian discrete groups by the CP symmetry.

CHIRAL ZEROMODES ON VORTEX-TYPE INTERSECTING FIVE-BRANE IN HETEROTIC STRING

2013 ◽  
Vol 21 ◽  
pp. 191-192
Author(s):  
MASAYA YATA
Keyword(s):  
Dirac Equation ◽  
String Theory ◽  
Boundary Conditions ◽  
Heterotic String ◽  
The Other ◽  
Two Dimensional ◽  
Complete Spectrum ◽  
Heterotic String Theory ◽  
Brane Solution ◽  
Opposite Chirality

We solve the gaugino Dirac equation on a smeared intersecting five-brane solution in E8 × E8 heterotic string theory to search for localized chiral zeromodes on the intersection. The background is chosen to depend on the full two-dimensional overall transverse coordinates to the branes. Under some appropriate boundary conditions, we compute the complete spectrum of zeromodes to find that, among infinite towers of Fourier modes, there exist only three localized normalizable zeromodes, one of which has opposite chirality to the other two.

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