Henrik Pedersen and Yat Sun Poon
Connected sums of self-dual manifolds and equivariant relative smoothings

In this paper we address a problem in differential geometry using tools from algebraic geometry and the theory of singular complex spaces. We obtain examples of compact four dimensional self-dual conformal manifolds with torus symmetry and positive scalar curvature from twistor spaces with divisors and we study the local moduli of such geometries.