scholarly journals Beta functions for the duality-invariant sigma model

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Roberto Bonezzi ◽  
Tomas Codina ◽  
Olaf Hohm
Keyword(s):  
String Theory ◽  
Sigma Models ◽  
Sigma Model ◽  
Equations Of Motion ◽  
Background Field ◽  
Field Method ◽  
Bosonic String ◽  
Two Dimensional ◽  
Background Field Method ◽  
Bosonic String Theory

Abstract The O(d, d) invariant worldsheet theory for bosonic string theory with d abelian isometries is employed to compute the beta functions and Weyl anomaly at one-loop. We show that vanishing of the Weyl anomaly coefficients implies the equations of motion of the Maharana-Schwarz action. We give a self-contained introduction into the required techniques, including beta functions, the Weyl anomaly for two-dimensional sigma models and the background field method. This sets the stage for a sequel to this paper on generalizations to higher loops and α′ corrections.

scholarly journals A TOY MODEL OF CLOSED STRING TACHYON EFFECTIVE ACTION

2005 ◽  
Vol 20 (07) ◽  
pp. 1481-1493
Author(s):  
J. KLUSOŇ
Keyword(s):  
Exact Solution ◽  
String Theory ◽  
Effective Action ◽  
Flat Space ◽  
Closed String ◽  
Space Time ◽  
Bosonic String ◽  
Two Dimensional ◽  
Linear Dilaton ◽  
Bosonic String Theory

In this paper we propose the toy model of the closed string tachyon effective action that has marginal tachyon profile as its exact solution in case of constant or linear dilaton background. Then we will apply this model for description of two-dimensional bosonic string theory. We will find that the background configuration with the spatial dependent linear dilaton, flat space–time metric and marginal tachyon profile is the exact solution of our model even if we take into account backreaction of tachyon on dilaton and on metric.

scholarly journals Integrability in sigma-models

2019 ◽  
pp. 205-247 ◽  
Author(s):  
K. Zarembo
Keyword(s):  
Sigma Models ◽  
Homogeneous Spaces ◽  
Beta Function ◽  
Background Field ◽  
Field Method ◽  
Two Dimensions ◽  
S Matrix ◽  
Background Field Method ◽  
Coset Models

The following topics are covered in this chapter: (1) Homogeneous spaces, (2) Classical integrability of sigma-models in two dimensions, (3) Topological terms, (4) Background-field method and beta-function, (5) S-matrix bootstrap in the O(N) model, (6) Supersymmetric coset models and strings on AdS(d) x X.

THE BACKGROUND FIELD METHOD AND THE ANOMALIES OF THE HETEROTIC σ-MODEL IN A CURVED (1, 0) SUPERSPACE

1991 ◽  
Vol 06 (17) ◽  
pp. 2971-2998 ◽  
Author(s):  
S.V. KETOV ◽  
O.A. SOLOVIEV
Keyword(s):  
Effective Action ◽  
Background Field ◽  
Field Method ◽  
Low Energy ◽  
Heterotic String ◽  
Explicit Calculation ◽  
Two Dimensional ◽  
Gauge Bosons ◽  
Background Field Method ◽  
Background Fields

The covariant (in the σ-model sense) background field method for calculating the anomalies of the heterotic string propagating on the background of its massless modes is developed in a curved superspace of the two-dimensional (1, 0) supergravity. As the massless background fields, we use a metric, an antisymmetric tensor, a dilaton and gauge bosons. Explicit calculation of the anomalies up to five loops is performed and the results are found to be in agreement with the known facts about the heterotic string low-energy effective action. The dilaton-dependent corrections to the anomalies at the two- and three-loop levels are shown to be absent.

scholarly journals THE ULTRAVIOLET PROPERTIES OF SUPERSYMMETRIC FIELD THEORIES

1989 ◽  
Vol 04 (08) ◽  
pp. 1871-1912 ◽  
Author(s):  
P. S. HOWE ◽  
K. S. STELLE
Keyword(s):  
Perturbation Theory ◽  
Higher Dimensions ◽  
Background Field ◽  
Field Method ◽  
Field Theories ◽  
Ultraviolet Divergence ◽  
Two Dimensional ◽  
Yang Mills ◽  
Supersymmetric Field Theories ◽  
Background Field Method

We review the structure of ultraviolet divergence cancellations in supersymmetric field theories. We discuss the various nonrenormalization theorems of superspace perturbation theory, both for extended and for simple supersymmetry. These theorems and the background field method are applied to super Yang-Mills theories in four and higher dimensions, to supergravity theories and to two-dimensional supersymmetric nonlinear σ-models.

scholarly journals FLUCTUATING STRINGS IN THE UNIVERSAL CONFINING STRING THEORY AND GLUODYNAMICS

1998 ◽  
Vol 13 (08) ◽  
pp. 581-592 ◽  
Author(s):  
D. V. ANTONOV
Keyword(s):  
String Theory ◽  
Inverse Correlation ◽  
Background Field ◽  
Field Method ◽  
Lattice Data ◽  
Energy Limit ◽  
Background Field Method ◽  
Effective String Theory ◽  
String Worldsheet

An effective string theory emerging from the bilocal approximation to the method of vacuum correlators in gluodynamics is shown to be well-described by the 4D theory of the massive Abelian Kalb–Ramond field interacting with the string, which is known to be the low energy limit of the universal confining string theory. This correspondence follows from the agreement of the behavior of the coefficient functions, which parametrize the gauge-invariant correlator of two gluonic field strength tensors, known from the lattice data, with their values obtained from the propagator of the Kalb–Ramond field. We discuss this correspondence in several aspects and demonstrate that the mass of the Kalb–Ramond field in this approach plays the role of the inverse correlation length of the vacuum, so that in the massless limit string picture disappears. Next, we apply the background field method, known in the theory of nonlinear sigma models, to obtain the action, which is quadratic in quantum fluctuations around a given (e.g. minimal) string worldsheet. Several nontrivial types of couplings of these fluctuations with the background worldsheet are obtained and discussed.

scholarly journals Gauged sigma-models with nonclosed 3-form and twisted Jacobi structures

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Athanasios Chatzistavrakidis ◽  
Grgur Šimunić
Keyword(s):  
Sigma Models ◽  
Sigma Model ◽  
Target Space ◽  
Two Dimensional ◽  
Courant Algebroids ◽  
Dirac Structures ◽  
Courant Algebroid ◽  
Abelian Case ◽  
Jacobi Manifolds ◽  
Jacobi Structure

Abstract We study aspects of two-dimensional nonlinear sigma models with Wess-Zumino term corresponding to a nonclosed 3-form, which may arise upon dimensional reduction in the target space. Our goal in this paper is twofold. In a first part, we investigate the conditions for consistent gauging of sigma models in the presence of a nonclosed 3-form. In the Abelian case, we find that the target of the gauged theory has the structure of a contact Courant algebroid, twisted by a 3-form and two 2-forms. Gauge invariance constrains the theory to (small) Dirac structures of the contact Courant algebroid. In the non-Abelian case, we draw a similar parallel between the gauged sigma model and certain transitive Courant algebroids and their corresponding Dirac structures. In the second part of the paper, we study two-dimensional sigma models related to Jacobi structures. The latter generalise Poisson and contact geometry in the presence of an additional vector field. We demonstrate that one can construct a sigma model whose gauge symmetry is controlled by a Jacobi structure, and moreover we twist the model by a 3-form. This construction is then the analogue of WZW-Poisson structures for Jacobi manifolds.

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