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arXiv · 1805.11116

The Chern-Schwartz-MacPherson class of an embeddable scheme

Paolo Aluffi
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Abstract

There is an explicit formula expressing the Chern-Schwartz-MacPherson class of a hypersurface in a nonsingular variety (in characteristic $0$) in terms of the Segre class of its jacobian subscheme; this has been known for a number of years. We generalize this formula to arbitrary embeddable schemes: for every subscheme $X$ of a nonsingular variety $V$, we define an associated subscheme $Y$ of a projective bundle over $V$ and provide an explicit formula for the Chern-Schwartz-MacPherson class of $X$ in terms of the Segre class of $Y$. If $X$ is a local complete intersection, a version of the result yields a direct expression for the Milnor class of $X$.

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Paolo Aluffi. 2018-05-28. The Chern-Schwartz-MacPherson class of an embeddable scheme. https://doi.org/10.1017/fms.2019.25

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