### 3 oktober 2005, kl 13.15-14.15, Uppsala, rum 3:513.

###
Dmitry Jakobson (McGill University): On nodal sets,
critical points, and quasi-symmetry
properties of eigenfunctions

**Abstract.**
We will discuss the following questions: approximating a "typical" point
on a manifold by nodal sets of eigenfunctions of the Laplacian;
"quasi-symmetry" properties of positive and negative parts of
eigenfunctions. We shall also describe a construction of a metric
on the 2-torus with a sequence of eigenfunctions, each of which has
exactly 16 critical points.