15 papers
Ghost Systems: A Vertex Algebra Point of View
W. Eholzer, L. Feher, A. Honecker
Fermionic and bosonic ghost systems are defined each in terms of a single vertex algebra which admits a one-parameter family of conformal structures. The observation that these str…
SL(2,Z)-Invariant Spaces Spanned by Modular Units
Wolfgang Eholzer, Nils-Peter Skoruppa
Characters of rational vertex operator algebras (RVOAs) arising in 2-dimensional conformal field theories often belong (after suitable normalization) to the (multiplicative) semigr…
Product Expansions of Conformal Characters
Wolfgang Eholzer, Nils-Peter Skoruppa
We describe several infinite series of rational conformal field theories whose conformal characters are modular units, i.e. which are modular functions having no zeros or poles in…
Unitarity of rational N=2 superconformal theories
W. Eholzer, M. R. Gaberdiel
We demonstrate that all rational models of the N=2 super Virasoro algebra are unitary. Our arguments are based on three different methods: we determine Zhu's algebra (for which we…
Conformal Characters and Theta Series
Wolgang Eholzer, Nils-Peter Skoruppa
We describe the construction of vector valued modular forms transforming under a given congruence representation of the modular group SL in terms of theta series. We app…
Conformal Characters and Theta Series
Wolfgang Eholzer, Nils-Peter Skoruppa
We describe the construction of vector valued modular forms transforming under a given congruence representation of the modular group SL(2,Z) in terms of theta series. We apply thi…