A pair of Calabi-Yau manifolds from a two parameter non-Abelian gauged linear sigma model

Abstract: We construct and study a two parameter gauged linear sigma model with gauge group $(U(1)^2\times O(2))/{\mathbb Z}_2$ that has a dual model with gauge group $(U(1)^2\times SO(4))/{\mathbb Z}_2$. The model has two geometric phases, three hybrid phases and one phase whose character is unknown. One of the geometric phases is strongly coupled and the other is weakly coupled, where strong versus weak is exchanged under the duality. They correspond to two Calabi-Yau manifolds with $(h^{1,1},h^{2,1})=(2,24)$ which are birationally inequivalent but are expected to be derived equivalent. A region of the discriminant locus in the space of Fayet-Iliopoulos-theta parameters supports a mixed Coulomb-confining branch which is mapped to a mixed Coulomb-Higgs branch in the dual model.