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• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeDec 17th 2009
• (edited Dec 17th 2009)

With Zoran I am working on entries related to monadic descent. While that is underway, I have added to

a section

and

• CommentRowNumber2.
• CommentAuthorUrs
• CommentTimeAug 5th 2011
• (edited Aug 5th 2011)

on the nCafé here Jim Stasheff asks who the “Sweedler” in Sweedler coring is . I don’t know. Zoran?

• CommentRowNumber3.
• CommentAuthorzskoda
• CommentTimeAug 5th 2011
• (edited Aug 5th 2011)

Sweedler is a major author on Hopf algebras, authoring an old book in the subject, and a professor emeritus at Cornell. His work on noncommuytative extensions dealing with Sweedler coring and related work of his colleague from Cornell Chase on noncommutative Galois, predating Hopf-Galois theory is from 1970s.

It is a pity that while one can make the descent for modules for noncommutative extensions, the descent for algebras (hence for affine schemes, as in SGA) works only in commutative case.

While you are working on monadic and comonadic descent you may be interested in related recent pages compatible idempotent monads (zoranskoda), domain globalization of functors (zoranskoda) and global Hopf-Galois extension (zoranskoda) which I am going to expand soon. One needs flatness of $G$ in the page on global Hopf-Gaois extension (this page was a sketch before the meeting with Gabi where the things were cleared and which is not reflected in writing yet).

• CommentRowNumber4.
• CommentAuthorUrs
• CommentTimeAug 5th 2011

Sweedler is a major author on Hopf algebras, authoring an old book in the subject, and a professor emeritus at Cornell. His work on noncommuytative extensions dealing with Sweedler coring and related work of his colleague from Cornell Chase on noncommutative Galois, predating Hopf-Galois theory is from 1970s.

Okay, thanks. I have copied that into the References-section at Sweedler coring

While you are working on monadic and comonadic descent you may be interested in related recent pages

I am not working on these entries at the moment. But if you link to your new entries from where it is relevant, then I will find them once I do!

• CommentRowNumber5.
• CommentAuthorUrs
• CommentTimeAug 6th 2011

Jim has more questions on Sweedler here.

Please, everyone who replies to Jim, please don’t forget to enter whatever information you have also into the relevant $n$Lab entry. For instance into the entry Moss Sweedler

• CommentRowNumber6.
• CommentAuthorzskoda
• CommentTimeAug 8th 2011

I answered his question at cafe now though I see no importance in collecting the data for a person’s entry, while more central entries can not get our attention and time.

• CommentRowNumber7.
• CommentAuthorUrs
• CommentTimeNov 17th 2013

I have cross-linked Sweedler coring with Adams spectral sequence a little. That canonical cosimplicial object induced from an $E_\infty$-algebra is its “Sweedler $\infty$-coring”. For whatever that’s worth-

• CommentRowNumber8.
• CommentAuthorUrs
• CommentTimeNov 26th 2013
• (edited Nov 26th 2013)

Added the following (and thereby the first) reference to Sweedler coring

In section 29 this has a good discussion of the Amitsur complex and the descent theorem. Added a pointer there, too.

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