Communications in Analysis and Geometry
Volume 11 (2003)
Curvature, Connected Sums, and Seiberg-Witten Theory
Pages: 809 – 836
We consider several differential-topological invariants of compact 4-manifolds which directly arise from Riemannian variational problems. Using recent results of Bauer and Furuta [5, 4], we compute these invariants in many cases that were previously intractable. In particular, we are now able to calculate the Yamabe invariant for many connected sums of complex surfaces.