TheJournal of Differential Geometry(JDG) is devoted to the publication of research papers in differential geometry and related subjects such as differential equations, mathematical physics, algebraic geometry and geometric topology. JDG was founded by the late Professor C.-C. Hsiung in 1967, and is owned by Lehigh University, Bethlehem, PA, U.S.A., and published under license by International Press of Boston, Inc.