5 problems

The new type IIB vacua under discussion are described by elliptically fibered Calabi–Yau manifolds, with the dilaton varying over an elliptic curve. On the heterotic side, consider…

Let $B'$ be a $\mathbf{P}^1$-bundle over $B$, with $B'=\mathbf{P}({\mathcal O}\oplus {\mathcal T})$, and let $X\to B'\to B$ be the corresponding elliptically fibered fourfold. Let…

In the heterotic string, let $R$ denote the spacetime curvature and $F$ the gauge-field strength, so that $R^2F^2$ denotes the corresponding effective-action interaction. The conje…

Let $X$ be a CalabiYau $5$-fold. The type I topological string on $X$ is the unoriented topological $B$-model with its open-string sector, whose gauge theory has structure group…

Consider the $SO(32)$ heterotic string compactified on a two-torus with constant abelian gauge flux, which is S-dual to the Type I string with the same gauge flux. T-duality in one…