Description |
Let $f: X \dashrightarrow Y$ be a birational and projective morphism between excellent and regular schemes. Then the higher direct images of the structure sheaf of $X$ under $f, R^i f_* O_X$, vanish for all positive integers $i$. In case $X$ and $Y$ are smooth schemes over a field of characteristic zero, this vanishing was proved by Hironaka as a corollary of his proof of the existence of resolutions of singularities. In case $X$ and Y are smooth over a field of positive characteristic the statement was proved by Chatzistamatiou-R\"ulling in 2011. In this talk I will explain the proof in the general case. This is joint work with Andre Chatzistamatiou. |