CHIRAL (SUPER) STRING ACTIONS

1990 ◽  
Vol 05 (07) ◽  
pp. 1341-1361 ◽  
Author(s):  
S.M. KUZENKO ◽  
O.A. SOLOVIEV
Keyword(s):  
String Theory ◽  
Space Time ◽  
Heterotic String ◽  
Bosonic String ◽  
Dimensional Case ◽  
Anomaly Cancellation ◽  
Heterotic String Theory ◽  
Covariant Action ◽  
Heterotic String Theories ◽  
String Theories

We present a covariant action describing chiral bosonic string theories in space-time dimensions d<26 and a covariant (1, 0) supersymmetric action describing heterotic string theories in space-time of dimension d<10. The anomaly cancellation conditions are found. In the four-dimensional case the supersymmetric action corresponds to the SO(44) heterotic string theory.

AMBIGUITIES AND BRST ANOMALIES IN 4D HETEROTIC STRING THEORIES

1990 ◽  
Vol 05 (03) ◽  
pp. 479-499 ◽  
Author(s):  
MASAHIRO YAMAGUCHI ◽  
TETSUYA ONOGI ◽  
IKUO ICHINOSE
Keyword(s):  
Dirac Equation ◽  
String Theory ◽  
Gauge Group ◽  
Vertex Operator ◽  
Heterotic String ◽  
Heterotic String Theory ◽  
Heterotic String Theories ◽  
Field Redefinition ◽  
String Theories ◽  
B Mixing

Ambiguity and BRST anomaly which appear in the string higher-loop calculation are studied in 4-dimensional heterotic string theory. In particular, we intensively investigate the models with an anomalous U(1) gauge group, and show that the possible ambiguities (A-B mixing, U(1) D-term tadpole etc.) are made to vanish by suitable field redefinition within a class of gauge slices satisfying the factorization hypothesis. Subtlety of massless three point amplitudes is clarified. We also extend the factorization hypothesis to the case of fermion amplitudes and study the ambiguities in them. We illustrate that the vertex operator correction which is consistent to the loop corrected Dirac equation indeed guarantees the absence of the ambiguity.

FIVEBRANE STRUCTURES

2009 ◽  
Vol 21 (10) ◽  
pp. 1197-1240 ◽  
Author(s):  
HISHAM SATI ◽  
URS SCHREIBER ◽  
JIM STASHEFF
Keyword(s):  
String Theory ◽  
Heterotic String ◽  
Target Space ◽  
Type Ii ◽  
Anomaly Cancellation ◽  
Heterotic String Theory ◽  
Dual Version ◽  
String Structure ◽  
Topological Obstructions ◽  
The One

We study the cohomological physics of fivebranes in type II and heterotic string theory. We give an interpretation of the one-loop term in type IIA, which involves the first and second Pontrjagin classes of spacetime, in terms of obstructions to having bundles with certain structure groups. Using a generalization of the Green–Schwarz anomaly cancellation in heterotic string theory which demands the target space to have a String structure, we observe that the "magnetic dual" version of the anomaly cancellation condition can be read as a higher analog of String structure, which we call Fivebrane structure. This involves lifts of orthogonal and unitary structures through higher connected covers which are not just 3- but even 7-connected. We discuss the topological obstructions to the existence of Fivebrane structures. The dual version of the anomaly cancellation points to a relation of string and Fivebrane structures under electric-magnetic duality.

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 NOTE ON ANOMALY CANCELLATION ON SO(32) HETEROTIC 5-BRANE

2011 ◽  
Vol 26 (19) ◽  
pp. 1453-1457 ◽  
Author(s):  
HARUNOBU IMAZATO ◽  
SHUN'YA MIZOGUCHI ◽  
MASAYA YATA
Keyword(s):  
String Theory ◽  
Tangent Bundle ◽  
Heterotic String ◽  
Localized Modes ◽  
Anomaly Cancellation ◽  
Heterotic String Theory

We show that the gauge, gravitational (tangent-bundle) and their mixed anomalies arising from the localized modes near a 5-brane in the SO(32) heterotic string theory cancel with the anomaly inflow from the bulk with the use of the Green–Schwarz mechanism on the brane, similarly to the E8×E8 5-brane case. We also compare our result with Mourad's analysis performed in the small-instanton limit.

scholarly journals Anomaly cancellation and smooth non-Kähler solutions in heterotic string theory

2006 ◽  
Vol 751 (1-2) ◽  
pp. 108-128 ◽  
Author(s):  
Katrin Becker ◽  
Melanie Becker ◽  
Ji-Xiang Fu ◽  
Li-Sheng Tseng ◽  
Shing-Tung Yau
Keyword(s):  
String Theory ◽  
Heterotic String ◽  
Anomaly Cancellation ◽  
Heterotic String Theory

scholarly journals ON THE ANOMALOUS MAGNETIC MOMENT IN HETEROTIC SUPERSTRINGS

1994 ◽  
Vol 09 (32) ◽  
pp. 3023-3033 ◽  
Author(s):  
ANDREA PASQUINUCCI ◽  
KAJ ROLAND
Keyword(s):  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Sum Rules ◽  
Space Time ◽  
Heterotic String ◽  
Planck Mass ◽  
External Space ◽  
Loop Level ◽  
Heterotic String Theories ◽  
String Theories

We address the problem of computing amplitudes with external space-time fermions in four-dimensional heterotic string theories. As a non-trivial example we consider the anomalous magnetic moment at one-loop level for an "electron" with mass of the order of the Planck mass. We check that the anomalous magnetic moment vanishes if the model is space-time supersymmetric, as required by the supersymmetric sum rules.

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.

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