Huh

June Huh

"Positivity of Chern classes of Schubert cells and varieties"

Chern-Schwartz-MacPherson class is a fuctorial Chern class defined for any (possibly singular or noncompact) algebraic varieties. I will give a geometric proof of a positivity conjecture of Aluffi and Mihalcea that Chern classes of Schubert cells and varieties in Grassmannians are positive. While the positivity conjecture is a purely combinatorial statement, a combinatorial “counting” proof is known only in very special cases.