[en] Supersymmetry transformations constitute a new, powerful technique of generating families of isospectral potentials. In this paper, the authors show that isospectral families of reflectionless potentials provide surprisingly simple expressions for the pure multi-soliton solutions of the KdV and other nonlinear evolution equations

[en] To a tachyon-free O(16) x O(16) heterotic string theory with anomaly-free properties in the low energy limit, the authors consider the anomaly of the compactified theory in 8, 6 and 4 dimensions. Furthermore, they investigate the global anomaly of the theory and discuss the compactified manifold which will give a consistent low energy theory

[en] The authors derive the relativistic quantum transport- and constraint equations for a relativistic field theory of baryons coupled to scalar and vector mesons. They extract a selfconsistent momentum dependent Vlasov term and the structure of quantum corrections for the Vlasov-Uehling-Uhlenbeck approach. The inclusion of pions and deltas into this transport theory is discussed

[en] The authors discuss the classical stability of a two-dimensional black hole which arises from the Jackiw model and pure gravity with a curvature squared term. For both these two models, they find that there exists the exponentially growing mode with time. Therefore, it seems that a two-dimensional black hole does not truly exist

[en] The Grassmannian σ model with a topological term is studied on a lattice. The θ dependence of the partition function and the Wilson loop are evaluated in the strong coupling limit. The latter is shown to be independent of the area at θ = π, as in the CP/sup N-1/ model

[en] The authors investigate how string vacua arise from N = 2 superconformal models. In particular, the authors discuss how Landau-Ginzburg models with appropriate central charge can be orbifoldized to construct string vacua. The authors develop techniques to compute the degeneracy and quantum numbers of the ground states of the LG Models in the twisted sectors, even for the cases where the underlying LG model is mot exactly solvable. This allows them to compute some interesting physical quantities such as the number of generations and anti-generations in the simplest compactification scenarios. The results agree with explicit computations in the cases where LG model is exactly solvable

[en] This paper reports that a minimal area problem imposing different length conditions on open and closed curves is shown to define a one-parameter family of covariant open-closed quantum string field theories. These interpolate from a recently proposed factorizable open-closed theory up to an extended version of Witten's open string field theory capable of incorporating on shell closed strings. The string diagrams of the latter define a new decomposition of the moduli spaces of Riemann surfaces with punctures and boundaries based on quadratic differentials with both first order and second order poles

[en] In this paper, the authors study c < 1 matter coupled to gravity in the Coulomb gas formalism using the double cohomology of the string BRST and Felder BRST charges. The authors find that states outside the primary conformal grid are related to the states of nonzero ghost number by means of descent equations given by the double cohomology. Some aspects of the Virasoro structure of the Liouville-Fock space are studied. As a consequence, states of nonzero ghost number are easily constructed by solving these descent equations. This enables the authors to map ghost number conserving correlation functions involving nonzero ghost number states into those involving states outside the primary conformal grid

[en] In this paper, the authors coupled the 2D black hole conformal field theory discovered by Witten to a (D - 1)-dimensional Euclidean bosonic string. The authors demonstrate that the resulting planar (= zero genus) string susceptibility is real for any 0 ≤ D ≤ 4

[en] In this paper the SU(4) color models represent possible alternatives to the standard model. These theories replace the color gauge group SU(3)_c by SU(4)_c. The SU(4)_c symmetry is assumed to be broken which leads to the SM as the effective low energy theory. An interesting feature of these theories is that the SU(4) symmetry breaking scale can be very low, and may be approximately at the same scale as the electroweak symmetry breaking. These models imply the existence of exotic electrically charged ±1/2 fermions. We examine various SU(4)_c models to explore the circumstances under which these models can have the exotic charged fermions in the interesting mass range m approx-gt 100 GeV