Seiberg-Witten Geometries Revisited
Yuji Tachikawa, Seiji Terashima
TL;DR
The paper establishes a universal Seiberg-Witten geometry for 4d $\mathcal{N}=2$ theories with a single simply-laced gauge group $G$ and matter in representations with $b_R\le h^\vee$, realized by a non-compact Calabi-Yau defined from $W_G$ and $X_R$ as $z + \frac{\Lambda^{2h^\vee}}{z} \prod_R \Lambda^{-b_R} X_R = W_G$. It systematically interprets $X_R$ as encoding hypermultiplets and demonstrates the construction's consistency with 6d $(2,0)$ compactifications on spheres with punctures, using decoupling to generate $X_R$ for exceptional representations (notably the $\mathbf{56}$ of $E_7$). The paper provides detailed case studies—the $2$-index antisymmetric of $SU(n)$, the $\mathbf{20}$ of $SU(6)$, and the $\mathbf{56}$ of $E_7$—to illustrate the method, including explicit Calabi-Yau equations, discriminant analyses, and Hitchin-field puncture data. These results unify multiple previous SW solutions within a single geometric framework and point to extensions to non-simply-laced groups and broader representation sets, highlighting the deep link between Calabi-Yau geometry, 6d defects, and 4d dynamics.
Abstract
We provide a uniform solution to 4d N=2 gauge theory with a single gauge group G=A,D,E when the one-loop contribution to the beta function from any irreducible component R of the hypermultiplets is less than or equal to half of that of the adjoint representation. The solution is given by a non-compact Calabi-Yau geometry, whose defining equation is built from explicitly known polynomials W_G and X_R, associated respectively to the gauge group G and each irreducible component R. We provide many pieces of supporting evidence, for example by analyzing the system from the point of view of the 6d N=(2,0) theory compactified on a sphere.
