Fields Geometric Analysis Colloquium
by Mingyang Li (Stony Brook University)
It is known from general relativity that axisymmetric stationary black holes can be reduced to axisymmetric harmonic maps into the hyperbolic plane $H^2$, while in the Riemannian setting, 4d Ricci-flat metrics with torus symmetry can also be locally reduced to such harmonic maps satisfying a tameness condition. We study such harmonic maps. Applications include a construction of infinitely many new families of complete, asymptotically flat, Ricci-flat 4-manifolds with arbitrarily large $b_2$. Joint work with Song Sun.
http://www.fields.utoronto.ca/activities/25-26/geometric-analysis-colloquium