Math Seminars.

Paul Feehan,
Witten's conjecture and gluing PU(2) monopoles.


We will discuss new results on gluing theory for PU(2) monopoles and applications to the proof of Witten's conjecture on the relation between the Donaldson and Seiberg-Witten invariants of smooth four-manifolds. The PU(2)-monopole moduli space provides a noncompact cobordism between links of compact moduli spaces of U(1) monopoles of Seiberg-Witten type and the (Donaldson) moduli space of anti-self-dual SO(3) connections, which appear as singularities in this larger moduli space. The purpose of the gluing theorem is to provide topological models for neighborhoods of ideal Seiberg-Witten moduli spaces appearing in lower levels of the Uhlenbeck compactification of the moduli space of PU(2) monopoles and thus permit calculations of their contributions to Donaldson invariants using the PU(2) monopole cobordism.