Hilbert schemes, separated variables, and D-Branes

We explain Sklyanin's separation of variables in geometrical terms and construct it for Hitchin and Mukai integrable systems. We construct Hilbert schemes of points on T* Σ for Σ = C, C* or elliptic curve, and on C²/Γ and show that their complex deformations are integrable systems of Calogero-Sutherland-Moser type. We present the hyperkähler quotient constructions for Hilbert schemes of points on cotangent bundles to the higher genus curves, utilizing the results of Hurtubise, Kronheimer and Nakajima. Finally we discuss the connections to physics of D-branes and string duality.