Spin Hurwitz Numbers and the Gromov-Witten Invariants of Kähler Surfaces

The classical Hurwitz numbers which count coverings of a complex curve have an analog when the curve is endowed with a theta characteristic. These “spin Hurwitz numbers,” recently studied by Eskin, Okounkov and Pandharipande, are interesting in their own right. By the authors’ previous work, they are also related to the Gromov–Witten invariants of Kähler… CONTINUE READING