### This Week’s Finds in Mathematical Physics (Week 287)

#### Posted by John Baez

In week287 of This Week’s Finds, discover Jean-Pierre Marquis and Gonzalo Reyes’ history of categorical logic. Then continue learning about rational homotopy theory! Learn a quick way to construct differential forms starting from any commutative algebra… and see how Sullivan used this to construct “rational differential forms” starting from any topological space.

Posted at December 20, 2009 7:49 AM UTC
## Re: This Week’s Finds in Mathematical Physics (Week 287)

The answer to the question about DGCA^op is surely “derived affine schemes”, no?