Yamabe metrics on cylindrical manifolds

Kazuo Akutagawa (Shizuoka University, Japan & U of Oregon)

This is joint work with B. Botvinnik. We study a particular class of open manifolds. In the smooth category these are manifolds with cylindrical ends. We give a natural setting for conformal geometry on such manifolds including an appropriate notion of cylindrical Yamabe constant/invariant. This leads to a corresponding version of the Yamabe problem on cylindrical manifolds.  We affirmatively solve this Yamabe problem: we prove existence results and analyze singularities of minimizing metrics near infinity.  These singularities turn out to be of a very particular type: either almost conical or almost cusp singularities.  We describe the limiting case, i.e., when the cylindrical Yamabe constant is equal to the Yamabe invariant of the sphere. We prove that in this case a cylindrical manifold coincides with the standard sphere punctured at finite number of points. In the course of studying the limiting case we establish a Positive Mass Theorem for manifolds with conical singularities. As a by-product, we revisit known results on surgery and the Yamabe invariant.


Fall 2001 meeting of the PNGS