| Résume | Abstract:
Given a line bundle L on a family of curves C, smooth and proper over a base scheme S, it is natural to study the locus of points of S where L is trivial. When one tries to extend to a family of stable curves, this ends up naturally yielding a cycle, not on S itself, but rather on a (log) blowup of S. One can choose to push down to S, but for some purposes the cycle on the blowup is the more fundamental object. I will describe two ways to compute the resulting class, known as the logarithmic double ramification cycle. This is joint work with Alessandro Chiodo |
