The interacting gauge covariant bosonic string

The interaction of the gauge covariant open bosonic string is presented in oscillator form, and in functional form. In the latter form, the string is described by commuting and anticommuting coordinates. The interaction is essentially the condition that the strings should overlap.     

The massive bosonic string in the center-of-mass gauge

The open Nambu string is revisited in the spirit of an early approach by Rohrlich. Strictly timelike motions only are considered. The proper-time of the center-of-mass is taken as preferred parameter. We propose a canonical formalism in terms of a countable infinity of variables, among them the modes. But the barycentric coordinates have noncommuting components, which makes possible a consistent quantization (in any dimension, four in particular) within the framework of a transverse space of states. If a maximal number of modes is further fixed, a transverse Hilbert space emerges, where spacetime displacements preserve the (positive-definite) scalar product.This article is dedicated to Fritz Rohrlich.     

Classical geometry of bosonic string dynamics

We develop a treatment of bosonic strings on a general curved background in which the volume element and the coordinates of the worldsheet are related in a similar way as canonically conjugate quantities in mechanics. The resultant formalism is a particular variant of the multi-phase-space approach to classical field theory put forward by Kijowski, Tulczyjew, and others. We study conservation laws within this framework and find that all conserved quantities are related to point symmetries, i.e., isometries of the underlying spacetime. Thus, the symmetries of relativistic mechanics coming from Killing tensors have no analogue here. We furthermore deduce from the present scheme the covariant version of the usual phase space.     

General symmetries of a string fluid space-time

It is shown that a string fluid is the simplest anisotropic fluid with vanishing heat flux. Furthermore it has the property that the Ricci tensor is obtained from the energy momentum tensor, and vice versa, if one interchanges the fluid variables. We use previous works on the collineations of anisotropic fluids, which include the string fluid as a particular case, to compute the kinematic and the dynamic effects of certain collineations of a string fluid. It is found that the possible spacetimes, which can carry a string fluid, are severely restricted and the possible string fluids in spacetimes, which can admit them are more or less fixed. We recover previous results on the effect of symmetries in string fluid spacetimes and get many new ones, for example the matter inheritance collineations. The study and the results are presented in a systematic manner, which allows the comprehension and the comparison of the restrictions imposed by each collineation. Finally one can use the same method of work for a systematic study of similar problems.     

On gauge invariant bosonic string quantization

It is argued that gauge invariance of the first quantized bosonic string is preserved by a mutual cancellation of the conformai and reparametrization anomalies. Implications for a geometric interpretation of second quantized string field theories are discussed in the conclusions.Invited talk presented at the International Conference Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 23–27, 1986.     

Conformal gravity and the bosonic string

We show that the Callan et al. effective equations of motion for the bosonic closed string in a non-trivial background may not be derived only from the bosonic part of theN=1 supergravity action of Manton and Chapline, but also from just a general conformally invariant theory of gravity. In our scheme the invariance under gauge transformations of the antisymmetric tensor field turns out to be a consequence of the metricity condition.     

Off-shell string amplitudes and singular states in bosonic string theory

The off-shell amplitudes with N external scalar particles are investigated. The dependence of the momenta is emphasized.     

New critical dimensions forq-deformed bosonic string

Applying the mass shell condition forq-deformed open and closed strings, new critical space-time dimensions are derived. Supported by the Algerian Ministry of High Education and Research under contract N^oD2501/17/01/93. Permanent address.     

Multiloop amplitudes for the bosonic Polyakov string

We provide a simple formula for multiloop amplitudes of the bosonic, closed oriented Polyakov string (in d = 26) as integrals over moduli space with respect to the Weil-Petersson measure. The integrand consists of Green functions and the determinants of laplacians acting on functions and vectors. We compute these determinants in terms of the lengths of the closed geodesics on the surface. They are finite and different from zero. The one on functions equals the derivative at 1 of the Selberg zeta function. A discussion of lengths of closed geodesics and coordinates for Teichmueller space is given.     

Evidence for nonperturbative string symmetries

String theory appears to admit a group of discrete field transformations — calledS dualities — as exact nonperturbative quantum symmetries. Mathematically, they are rather analogous to the better-knownT duality symmetries, which hold perturbatively. In this Letter the evidence forS duality is reviewed and some speculations are presented.     

Exploring the spectrum of regularized bosonic string theory

Journal of Experimental and Theoretical Physics - We implement a UV regularization of the bosonic string by truncating its mode expansion and keeping the regularized theory “as diffeomorphism...     

The operator quantization of the open bosonic string: Field algebra

Our aim in this paper is to make explicit the operator theory of the heuristic open Bosonic string and to abstract a suitable field algebra for the string. This is done on a Fock-Krein space and we examine integrability and J-unitary implementability of all the defining transformations of the string, i.e. time translations, gauge transformations and Poincaré transformations. The results obtained agree partially with those of Bowick and Rajeev, i.e. the gauge transformations do not leave the Fock-Krein complex structure invariant. Once we obtained integrated transformation groups on a suitable symplectic space for the infinitesimal transformations of the string, and proved implementability of these for the Fock-Krein representation, we are then free to define an abstract C^*-algebra carrying all the algebraic information of the string, and to examine different representations.     

BRST invariant tadpole operator in the bosonic string

Using a BRST invariant three-reggeon vertex we construct an explicit expression for the BRST invariant planar tadpole operator for the bosonic string. Joined to an (N+1)-reggeon vertex it yields the correct expression for the one-loop N-tachyon amplitude.