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arXiv · 2506.01547

Quadratic Segre indices

Felipe Espreafico·Stephen McKean·Sabrina Pauli
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Abstract

We prove that the local Euler class of a line on a degree $2n-1$ hypersurface in projective $n+1$ space is given by a product of indices of Segre involutions. Segre involutions and their associated indices were first defined by Finashin and Kharlamov over the reals. Our result is valid over any perfect field of characteristic not 2 and gives an infinite family of problems in enriched enumerative geometry with a shared geometric interpretation for the local type.

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Felipe Espreafico, Stephen McKean, Sabrina Pauli. 2025-06-02. Quadratic Segre indices. https://arxiv.org/abs/2506.01547

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