Klein bottles and simple currents

• Author(s): Huiszoon, Lennaert ; Schellekens, Adrianus ; Sousa, Nuno
• Date: 1999
• Persistent ID: http://hdl.handle.net/10400.2/2342
• Origin: Repositório Aberto da Universidade Aberta
• Subject(s): Física; Teoria de cordas; Physics; String theory
• Document Type: Article
• Language: English

Description

The standard Klein bottle coefficient in the construction of open descendants is shown to equal the Frobenius-Schur indicator of a conformal field theory. Other consistent Klein bottle projections are shown to correspond to simple currents. These observations enable us to generalize the standard open string construction from C-diagonal parent theories to include non-standard Klein bottles. Using (generalizations of) the Frobenius-Schur indicator we prove positivity and integrality of the resulting open and closed string state multiplicities for standard as well as non-standard Klein bottles.