Conformal invariance, supersymmetry and string theory

Abstract

Covariant quantization of string theories is developed in the context of conformal field theory and the BRST quantization procedure. The BRST method is used to covariantly quantize superstrings, and in particular to construct the vertex operators for string emission as well as the supersymmetry charge. The calculation of string loop diagrams is sketched. We discuss how conformal methods can be used to study string compactification and dynamics.

Stringy instantons at orbifold singularities

“…More specifically, they source the metric h µν , the R-R four-form potential C µνρσ and two twisted scalars b and c from the NS-NS and R-R sector respectively. This means that the disk one-point function of their vertex operators [31,32] is non vanishing when the disk boundary is attached to such D3-branes. (Indeed in this way or, equivalently, by using the boundary-state formalism [33,34], one can derive the profile for these fields.…”

Analytic solutions for marginal deformations in open superstring field theory

“…It is Grassmann even and has ghost number 0 and picture number 0. The superghost sector is described by η, ξ, and φ [48,49], and the zero modes of η and ξ are included in the Hilbert space. The operator η 0 is the zero mode of η and a derivation with respect to the star product.…”

On gauge couplings and thresholds in Type I Gepner models and otherwise

“…Unitary N = 2 minimal models are known to form a discrete series [110]. They are equivalent to the quotients SU(2) k × U(1) 2 /U(1) k+2 , so that the central charge is given by …”