What do dg-categories form?

Dmitry Tamarkin
2007 Compositio Mathematica  
We introduce a homotopy 2-category structure on the collection of dg-categories, dgfunctors, and their derived transformations. This construction provides for a conceptual proof of Deligne's conjecture on Hochschild cochains.
doi:10.1112/s0010437x07002771 fatcat:wlrkxppohzdbhnzyma6gc5vh3u