제목 : Generic p-rank for Semi-stable Fibrations
연사 : Junmyeong Jang (장준명) 박사
소속 : KIAS
날짜 : 12월 17일 수요일 (16:00~17:30)
장소 : 세미나실 (#1409)
초록 : Over a positive characteristic field, for a semi-stable fibraiton from a proper smooth surface to a proper smooth curve, the semi-positivity theorem may fail. In this talk, we will give a criterion for validity or failure of the semi-positivity theorem in terms of the p-rank of the generic fiber. As applications, we will construct a counterexample to Parshin's expectation on Miyaoka-Yau inequality and will make a result on variations of p-ranks of reductions for some non-closed points of a moduli space of higher genus curves over a number field.