scholarly journals CLOSED BOSONIC STRING PARTITION FUNCTION IN TIME INDEPENDENT EXACT pp-WAVE BACKGROUND

2006 ◽  
Vol 21 (05) ◽  
pp. 995-1013
Author(s):  
AGAPITOS HATZINIKITAS ◽  
IOANNIS SMYRNAKIS
Keyword(s):  
Partition Function ◽  
Light Cone ◽  
Free Field ◽  
Bosonic String ◽  
Covariant Form ◽  
Modular Invariant ◽  
Light Cone Gauge ◽  
Axion Field ◽  
Pp Wave ◽  
Closed Bosonic String

The modular invariance of the one-loop partition function of the closed bosonic string in four dimensions in the presence of certain homogeneous exact pp -wave backgrounds is studied. In the absence of an axion field, the partition function is found to be modular invariant and equal to the free field partition function. The partition function remains unchanged also in the presence of a fixed axion field. However, in this case, the covariant form of the action suggests summation over all possible twists generated by the axion field. This is shown to modify the partition function. In the light-cone gauge, the axion field generates twists only in the worldsheet σ-direction, so the resulting partition function is not modular invariant, hence wrong. To obtain the correct partition function one needs to sum over twists in the t-direction as well, as suggested by the covariant form of the action away from the light-cone gauge.

PHASE STRUCTURE IN BOSONIC STRING THEORY

1990 ◽  
Vol 05 (20) ◽  
pp. 3929-3941 ◽  
Author(s):  
SIMON DALLEY ◽  
TIM MORRIS
Keyword(s):  
String Theory ◽  
Lattice Model ◽  
Phase Structure ◽  
Light Cone ◽  
Minimum Distance ◽  
Arbitrary Dimension ◽  
Bosonic String ◽  
Light Cone Gauge ◽  
Duality Symmetry ◽  
Bosonic String Theory

We carefully reanalyze a lattice model of oriented closed bosonic strings in light cone gauge due to Klebanov and Susskind, completing the procedure suggested by these authors for solving for the spectrum. Our results enable us to relate the concept of minimum distance in bosonic string theory in uncompactified space to the phase structure of strings on tori, and in particular their duality symmetry. Generalizations to a theory of arbitrary dimension are given.

scholarly journals O(D,D)-covariant two-loop β-functions and Poisson-Lie T-duality

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Falk Hassler ◽  
Thomas B. Rochais
Keyword(s):  
Lie Symmetry ◽  
Bosonic String ◽  
Covariant Form ◽  
Quantum Regime ◽  
The One ◽  
Closed Bosonic String

Abstract We show that the one- and two-loop β-functions of the closed, bosonic string can be written in a manifestly O(D,D)-covariant form. Based on this result, we prove that1) Poisson-Lie symmetric σ-models are two-loop renormalisable and2) their β-functions are invariant under Poisson-Lie T-duality.Moreover, we identify a distinguished scheme in which Poisson-Lie symmetry is manifest. It simplifies the calculation of two-loop β-functions significantly and thereby provides a powerful new tool to advance into the quantum regime of integrable σ-models and generalised T-dualities. As an illustrating example, we present the two-loop β-functions of the integrable λ- and η-deformation.

OPEN STRINGS AS Z2-ORBIFOLDS OF CLOSED STRINGS

1991 ◽  
Vol 06 (27) ◽  
pp. 2483-2496
Author(s):  
GREG NAGAO
Keyword(s):  
Open String ◽  
Closed String ◽  
Bosonic String ◽  
Modular Invariant ◽  
Open Strings ◽  
Loop Expansion ◽  
Invariant Formulation ◽  
Closed Bosonic String ◽  
String Theories

We present a modular invariant formulation of the open string in terms of the closed string. Chan–Paton factors are understood as multiplicities which arise from a factorization of the closed string. This interpretation of the Chan–Paton factors suggests that the SO (2D/2) open string is consistent to all orders of the loop expansion. We show that the open string may be viewed as a Z2-orbifold of the closed string. Relations are found between various string theories which seem to reinforce an earlier suggestion by Freund that all string theories are derivable from the D = 26 orientable closed bosonic string.

scholarly journals T-DUALITY OF NSR SUPERSTRING: THE WORLDSHEET PERSPECTIVE

2012 ◽  
Vol 27 (23) ◽  
pp. 1250140 ◽  
Author(s):  
JNANADEVA MAHARANA
Keyword(s):  
Equations Of Motion ◽  
Bosonic String ◽  
Target Space ◽  
Vertex Operators ◽  
Covariant Form ◽  
Dimensional Torus ◽  
Duality Symmetry ◽  
Superspace Formalism ◽  
Closed Bosonic String ◽  
Equations Of Motions

We formulate target space duality symmetry of NSR superstring from the perspectives of worldsheet. The worldsheet action is presented in the superspace formalism in the presence of massless backgrounds. We start from a [Formula: see text]-dimensional target space worldsheet action and compactify the theory on a d-dimensional torus, Td. It is assumed that the backgrounds are independent of compact (super)coordinates. We adopt the formalism of our earlier work to introduce dual supercoordinates along compact directions and introduce the corresponding dual backgrounds. It is demonstrated that combined equations of motion of the two sets of coordinates can be expressed in a manifestly O(d, d) covariant form analogous to the equations of motions for closed bosonic string derived by us. Furthermore, we show that the vertex operators associated with excited massive levels of NSR string can be expressed in an O(d, d) invariant form generalizing earlier result for closed bosonic string.

scholarly journals Graviton-Scalar Interaction in the pp-Wave Background

2003 ◽  
Vol 18 (21) ◽  
pp. 1441-1462
Author(s):  
K. Bobkov
Keyword(s):  
Field Theory ◽  
String Field Theory ◽  
Light Cone ◽  
Tree Level ◽  
Scalar Interaction ◽  
Superstring Theory ◽  
Light Cone Gauge ◽  
Interaction Vertex ◽  
Pp Wave

We compute the graviton two scalar off-shell interaction vertex at tree level in Type IIB superstring theory on the pp-wave background using the light-cone string field theory formalism. We then show that the tree level vertex vanishes when all particles are on-shell and conservation of p+ and p- are imposed. We reinforce our claim by calculating the same vertex starting from the corresponding SUGRA action expanded around the pp-wave background in the light-cone gauge.

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