Pencils of quadrics and 2-Selmer groups of Jacobians of hyperelliptic curves

Since Bhargava and Shankar's new method of counting orbits, average orders of the 2,3,4,5-Selmer groups of elliptic curves over Q have been obtained. In this talk we will look at 2-Selmer groups of Jacobians of hyperelliptic curves over Q, and see how they are related to orbit counting using pencils of quadrics. Previous knowledge of Selmer groups is not required.