Involution-dependent constants and the cancellation of divergences in the one-loop open-string amplitude

1988 ◽  
Vol 38 (2) ◽  
pp. 569-577 ◽  
Author(s):  
Greg Nagao
Keyword(s):  
Open String ◽  
String Amplitude ◽  
The One

scholarly journals Geometry of orientifold vacua and supersymmetry breaking

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Thibaut Coudarchet ◽  
Emilian Dudas ◽  
Hervé Partouche
Keyword(s):  
Field Theory ◽  
Supersymmetry Breaking ◽  
Effective Field Theory ◽  
Scalar Potential ◽  
Open String ◽  
Closed String ◽  
Effective Field ◽  
Internal Space ◽  
Gravitino Mass ◽  
The One

Abstract Starting from a peculiar orientifold projection proposed long ago by Angelantonj and Cardella, we elaborate on a novel perturbative scenario that involves only D-branes, together with the two types of orientifold planes O± and anti-orientifold planes $$ {\overline{\mathrm{O}}}_{\pm } $$ O ¯ ± . We elucidate the microscopic ingredients of such models, connecting them to a novel realization of brane supersymmetry breaking. Depending on the position of the D-branes in the internal space, supersymmetry can be broken at the string scale on branes, or alternatively only at the massive level. The main novelty of this construction is that it features no NS-NS disk tadpoles, while avoiding open-string instabilities. The one-loop potential, which depends on the positions of the D-branes, is minimized for maximally broken, non-linearly realized supersymmetry. The orientifold projection and the effective field theory description reveal a soft breaking of supersymmetry in the closed-string sector. In such models it is possible to decouple the gravitino mass from the value of the scalar potential, while avoiding brane instabilities.

WIGNER THEORY OF THE NAMBU STRING: (II) THE CLOSED STRING

1992 ◽  
Vol 07 (17) ◽  
pp. 4107-4148 ◽  
Author(s):  
F. COLOMO ◽  
L. LUSANNA
Keyword(s):  
Minkowski Space ◽  
Canonical Basis ◽  
Open String ◽  
Closed String ◽  
Zero Modes ◽  
Left And Right ◽  
The One

A set of relative variables for the closed string with P2>0 is found, which has Wigner covariance properties. They allow one to obtain global Lorentz-invariant abelianizations of the constraints, like for the open string, and then global Lorentz-invariant canonically conjugated gauge variables are found. But now there are two extra zero modes in the constraints and in the gauge variables, related to the gauge arbitrariness of the origin σ0 of the circle σ∈(−n, π) embedded in Minkowski space, σ↦xμ(σ). By means of the multitemporal approach a noncanonical redundant set of Dirac observables for the left and right modes is defined; they transform as spin-1 Wigner vectors and satisfy constraints of the same kind as in σ models. The quantization is not made, because a canonical basis of observables is still lacking, but the program to be followed to find them is just the same as the one delineated for the case of the open string.

scholarly journals Comments on open string with ‘massive’ boundary term

2020 ◽  
Vol 476 (2236) ◽  
pp. 20190748
Author(s):  
Arkady A. Tseytlin
Keyword(s):  
Scattering Amplitudes ◽  
Partition Function ◽  
Gauge Field ◽  
Path Integral ◽  
Open String ◽  
One Dimensional ◽  
Conformally Invariant ◽  
Additional Constant ◽  
The One ◽  
Definition Of

We discuss possible definition of open string path integral in the presence of additional boundary couplings corresponding to the presence of masses at the ends of the string. These couplings are not conformally invariant implying that as in a non-critical string case one is to integrate over the one-dimensional metric or reparametrizations of the boundary. We compute the partition function on the disc in the presence of an additional constant gauge field background and comment on the structure of the corresponding scattering amplitudes.

PARTITION FUNCTIONS OF THE SUPERCONFORMAL GHOST THIRRING MODEL

1989 ◽  
Vol 04 (20) ◽  
pp. 5553-5574 ◽  
Author(s):  
D. Z. FREEDMAN ◽  
K. PILCH
Keyword(s):  
Energy Spectrum ◽  
Path Integral ◽  
Formal Series ◽  
Open String ◽  
Integral Representations ◽  
Thirring Model ◽  
Partition Functions ◽  
First Order ◽  
Integral Methods ◽  
The One

The one-loop partition functions of the superconformal Thirring model for first order b − c and β − γ ghost fields are studied for both closed and open string boundary conditions. Bosonized partition functions are given by formal series which usually diverge because the energy spectrum of the theory is unbounded below as a correlate of nonunitarity. However, the same partition functions are then calculated by path integral methods directly in the fermionic formulation, and well-defined (convergent) integral representations are obtained. A formal series expansion of those integrals reproduces the bosonized partition functions.

LONG OPEN STRING AND NON-SINGLET SECTOR IN MATRIX QUANTUM MECHANICS

2008 ◽  
Vol 23 (14n15) ◽  
pp. 2091-2098
Author(s):  
YUTAKA MATSUO
Keyword(s):  
Quantum Mechanics ◽  
Scattering Amplitude ◽  
Long Strings ◽  
Open String ◽  
Wave Functions ◽  
Liouville Theory ◽  
Young Diagrams ◽  
The One ◽  
Model Correlation ◽  
Matrix Quantum

Recently Maldacena conjectured that the long folded open string in noncritical string theory is described by the non-singlet sectors of matrix quantum mechanics. In this paper, we first describe how to obtain the exact wave functions of this system when the sign of the potential is reverted, based on a work with Y. Hatsuda. The wave functions are labeled by three Young diagrams and the degeneracy associated with it is given by the group theoretical quantities. In the second part, based on a work with J.-E. Bourgine, K. Hosomichi and I. Kostov, we derive the scattering amplitude of two long strings and which coincides with the result from the Liouville theory. It generalizes the result of the one-body scattering by Kostov and uses the relation with the two-matrix model correlation functions.

P-LOOP VACUUM AMPLITUDE IN THE OPEN BOSONIC STRING THEORY

1988 ◽  
Vol 03 (05) ◽  
pp. 511-516 ◽  
Author(s):  
I.D. VAISBURD
Keyword(s):  
String Theory ◽  
Moduli Space ◽  
Modular Group ◽  
Open String ◽  
Bosonic String ◽  
The Real ◽  
String Amplitude ◽  
Bosonic String Theory

P-loop open string amplitude is constructed as the integral over the real section of the moduli space. The modular group of the open string is presented.

scholarly journals FINITENESS AND DECOUPLING IN OPEN STRING THEORIES

1989 ◽  
Vol 04 (17) ◽  
pp. 4353-4389 ◽  
Author(s):  
JAN GOVAERTS
Keyword(s):  
Gauge Group ◽  
Open String ◽  
Closed String ◽  
Bosonic String ◽  
Loop Level ◽  
The One ◽  
String Theories

Quantum consistency of open string theories is considered at the one-loop level, using a unified and consistent regularization of all divergences. Finiteness of all amplitudes with open string states is shown to be possible for any SO (n) or USp (n) gauge group. Two consequences of the nonunitarity of tachyonic theories are discussed; the presence of unphysical cuts in amplitudes and the nondecoupling of null states. If not for contributions of the open string tachyon, decoupling of all null open bosonic string states would be obtained for SO (2D/2) independently of the regularization, corresponding to vanishing tadpoles of unphysical closed string states.

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