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Special Seminar: Sections of line bundles on the moduli space of pointed rational curves

Special Events

Speaker: Dr. Noah Giansiracusa, University of California, Berkeley
Location: 1147 MSB
Start time: Fri, Jan 10 2014, 4:10PM

The moduli space \overline{M_{0,n}}, introduced by Grothendieck and Deligne-Mumford-Knudsen, is a compactification of the space of n distinct points on the Riemann sphere. It has served as a fertile testing ground to explore many phenomena of moduli spaces in algebraic geometry, and some questions about it raised by Mumford in the 70s remain open. One of these is to describe the convex cone of effective divisor classes, or in other words, sections of line bundles up to equivalence. In this talk I will discuss joint work with B. Doran and D. Jensen in which we provide a new perspective on this question in terms of simplicial complexes, construct counterexamples to a conjectural description of this cone, and show how once again, the geometry of \overline{M_{0,n} relates to many other beautiful areas of mathematics.

A Department Tea will follow the Talk in the Alder Room.