Toric polar maps and characteristic classes

Thiago Fassarella; Nivaldo Medeiros; Rodrigo Salomão

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arXiv · 2205.03957

Toric polar maps and characteristic classes

Thiago Fassarella·Nivaldo Medeiros·Rodrigo Salomão

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Abstract

Given a hypersurface in a complex projective space, we prove that the multidegrees of its toric polar map agree, up to sign, with the coefficients of the Chern-Schwartz-MacPherson class of a distinguished open set, namely the complement of the union of the hypersurface and the coordinate hyperplanes. In particular, the degree of the toric polar map is given by the signed topological Euler characteristic of the distinguished open set. For plane curves, a precise formula for the degree of the toric polar map is obtained in terms of local invariants. Finally, we construct families, in arbitrary dimension, of irreducible hypersurfaces whose toric polar map is birational.

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Thiago Fassarella, Nivaldo Medeiros, Rodrigo Salomão. 2022-05-08. Toric polar maps and characteristic classes. https://arxiv.org/abs/2205.03957

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