相关论文: Charged Strings and Spectrum-Generating Algebra

When an open string ends with charges on a D2-brane, which involves constant background magnetic field perpendicular to the brane, we construct the spectrum-generating algebra for this charged string, which assures that our system is…

The spectrum-generating algebra (SGA) for charged superstrings placed in constant background magnetic fields is constructed. Contrary to the neutral string this algebra is characteristic of including the cyclotron frequency. The Regge…

When open strings end with a charge q on a D2-brane, which involves constant background magnetic field B perpendicular to the brane, we calculate the Hall conductivity for these charged strings. We also construct the corresponding…

When a charged heterotic string is placed in a constant magnetic field B, we show that this system can be solved exactly by using the cyclotron frequency. We then calculate anomalies of the super Virasoro algebra, and give the corresponding…

In hep-th/0211011 we started a systematic investigation of open strings in the plane wave background. In this paper we continue the analysis by discussing the superalgebras of conserved charges, the spectra of open strings, and the spectra…

We construct the spectrum generating algebra (SGA) for a free particle in the three dimensional sphere $S^3$ for both, classical and quantum descriptions. In the classical approach, the SGA supplies time-dependent constants of motion that…

In this paper, we construct a Spectrum Generating Algebra (SGA) for a quantum system with purely continuous spectrum: the quantum free particle in a Lobachevski space with constant negative curvature. The SGA contains the geometrical…

The Dirac quantization is performed for the constrained system of the open string with different charges located at both ends in the constant background B field. Noncommutativity reveals to commutators [X, X], [P, P] and also [X,P] at both…

We list the spectrum generating algebras for string theory and M-theory compactified on various backgrounds of the form $AdS_{d+1} \times S^n$. We identify the representations of these algebras which make up the classical supergravity…

The entropy of a near-extremal black hole made of parallel D-branes has been shown to agree, upto a numerical factor, with that of the gas of massless open string states on the brane worldvolume when the string coupling is chosen suitably.…

Two dimensional string theory is known to have an infinite dimensional symmetry, both in the continuum formalism as well as in the matrix model formalism. We develop a systematic procedure for computing the conserved charges associated with…

The possible tensor constructions of open string theories are analyzed from first principles. To this end the algebraic framework of open string field theory is clarified, including the role of the homotopy associative A_\infty algebra, the…

We extend the systematic construction of bosonic DDF operators to the light-like linear dilaton background to investigate how higher-spin string states behave beyond flat spacetime. Using previous results, we show that the…

We establish a translation dictionary between open and closed strings, starting from open string field theory. Under this correspondence, (off-shell) level-matched closed string states are represented by star algebra projectors in open…

In this thesis we discuss some nonperturbative and noncommutative aspects of string theory. We present low-energy background field solutions corresponding to various D-branes (and their bound states) and intersecting branes in flat and…

We discuss two dimensional string theories containing gauge fields introduced either via coupling to open strings, in which case we get a Born-Infeld type action, or via heterotic compactification. The solutions to the modified background…

This paper addresses several unsettled issues associated with string creation in systems of orthogonal Dp-D(8-p) branes. The interaction between the branes can be understood either from the closed string or open string picture. In the…

Based on results about open string correlation functions, a nonassociative algebra was proposed in a recent paper for D-branes in a background with nonvanishing $H$. We show that our associative algebra obtained by quantizing the endpoints…

We investigate the evolution of small perturbations around charged black strings and branes which are solutions of low energy string theory. We give the details of the analysis for the uncharged case which was summarized in a previous…

We study the closed string emission from an unstable D$p$-brane with constant background electric field in bosonic string theory. The average total number density and the average total energy density of emitted closed strings are explicitly…