76 citations · 217 across the 9 of their papers we have counts for
9 papers
Boundary Fixed Points, Enhanced Gauge Symmetry and Singular Bundles on K3
J. Fuchs, P. Kaste, W. Lerche +3
We investigate certain fixed points in the boundary conformal field theory representation of type IIA D-branes on Gepner points of K3. They correspond geometrically to degenerate b…
1/4 BPS States and Non-Perturbative Couplings in N=4 String Theories
W. Lerche, S. Stieberger
We compute certain 2K+4-point, one-loop couplings in the type IIA string compactified on K3 x T^2, which are related to a topological index on this manifold. Their special feature…
Quartic Gauge Couplings from K3 Geometry
W. Lerche, S. Stieberger, N. P. Warner
We show how certain F^4 couplings in eight dimensions can be computed using the mirror map and K3 data. They perfectly match with the corresponding heterotic one-loop couplings, an…
Prepotential, Mirror Map and F-Theory on K3
W. Lerche, S. Stieberger
We compute certain one-loop corrections to F^4 couplings of the heterotic string compactified on T^2, and show that they can be characterized by holomorphic prepotentials. We then…
Exceptional SW Geometry from ALE Fibrations
W. Lerche, N. P. Warner
We show that the genus 34 Seiberg-Witten curve underlying Yang-Mills theory with gauge group yields physically equivalent results to the manifold obtained by fibration…
On the Algebraic Structure of Gravitational Descendants in CP(n-1) Coset Models
W. Lerche, N. P. Warner
We investigate how specific free-field realizations of twisted N=2 supersymmetric coset models give rise to natural extensions of the ``matter'' Hilbert spaces in such a manner as…