Although it won’t be evident from this site, I’ve been gradually editing the notes, mainly in response to suggestions and corrections you have sent me or told me. Because things are (very slightly) rearranged, there are lots of temporarily broken links, so I’ve not posted a version in a long time. I think I would like that to change. There are lots of little things I want to tweak — for example, adding Eric Larson’s “proof from the book” of Cohomology and Base Change, and Arthur Ogus’ proof (also “from the book”) of the local criterion for flatness.

But what is moving me to write this today is an email from Zihong Chen, asking about the flawed proof of the Kunneth formula in an earlier version of the notes (since removed, but it may have been after my last posting). I’d scribbled down notes on what I should have said, so I thought I should type it properly, and post it here. (I’m not sure if I will add it to the notes. The price is two pages, which is pretty steep at this point. But it fits squarely into the narrative of the Rising Sea.)

kunnethDownload