7 papers
Through the Looking Glass
David R. Morrison
It is frequently possible to produce new Calabi-Yau threefolds from old ones by a process of allowing the complex structure to degenerate to a singular one, and then performing a r…
Resolving Singularities in (0,2) Models
J. Distler, B. Greene, D. Morrison
In contrast to the familiar (2,2) case, the singularities which arise in the (0,2) setting can be associated with degeneration of the base Calabi-Yau manifold {\it and/or}\/ with d…
Geometric Singularities and Enhanced Gauge Symmetries
M. Bershadsky, K. Intriligator, S. Kachru +3
Using ``Tate's algorithm,'' we identify loci in the moduli of F-theory compactifications corresponding to enhanced gauge symmetry. We apply this to test the proposed F-theory/heter…
Compactifications of F-Theory on Calabi--Yau Threefolds -- II
David R. Morrison, Cumrun Vafa
We continue our study of compactifications of F-theory on Calabi--Yau threefolds. We gain more insight into F-theory duals of heterotic strings and provide a recipe for building F-…
Enhanced Gauge Symmetry in Type II String Theory
Sheldon Katz, David R. Morrison, M. Ronen Plesser
We show how enhanced gauge symmetry in type II string theory compactified on a Calabi--Yau threefold arises from singularities in the geometry of the target space. When the target…
Summing the Instantons: Quantum Cohomology and Mirror Symmetry in Toric Varieties
David R. Morrison, M. Ronen Plesser
We use the gauged linear sigma model introduced by Witten to calculate instanton expansions for correlation functions in topological sigma models with target space a toric variety…