作者机构:[1]Department o] Mathematical Sciences, Tsinghua University, Beijing 100084, China, [2]Department of Mathematics, Courant Institute of Mathematical Sciences, New York University,New York, NY 10012, USA
相关基金:Acknowledgments. This work was supported by the NSFC Project No. 11071139, the Na- tional Basic Research Program of China under the grant 2011CB309705, Tsinghua University Initiative Scientific Research Program.