Curvature, Connected Sums, and Seiberg-Witten Theory

摘要

We consider several differcntial-topological invariants of compact 4-manifolds which directly arise from R.ieniaimian variatioiial problems. Using recent results of Bauer and Fnruta [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.