Deligne-Mumford moduli spaces are moduli spaces for projective curves with mild (normal crossing) singularities. They are important tools in mathematics and mathematical physics (their volumes are related to the KdV hierarchy, and they were used by de Jong in his famous theorem on the existence of smooth alterations). In this talk, I explain a way in which they resemble polyhedra: they carry a filtration such that the inclusion of the k'th filtrand is a k-homotopy equivalence.
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After the seminar we will take the speaker to lunch.
See the Algebra Seminar web page for information about other seminars in the series.
James East jamese@maths.usyd.edu.au