2010
Jan. 8, topology seminar, Caltech, Los Angeles
May 17-21, invited speaker, Barrett Memorial Lectures, University of Tennessee, Knoxville
June 4-6, speaker and co-organizer, "topology and geometry in dimension three"- celebrating Jaco's 70-th birthday, University of Oklahoma, Stillwater
July 5-9, quantum geometry and topology, C.I.R.M., France
July 19-30, invited speaker, Topology, Geometry and Dynamics of character varieties, National University of Singapore.
Sept. 1-3, invited speaker, Encounters between mathematicians and theoretical physicists, University of Strassboug, France
2009
Jan. 5-6, invited speaker, AMS meeting at Washington DC.
Jan. 10-17, invited speaker, Oberwolfach workshop on discrete differential geometry
Feb. 11-15, colloquium talk at Arizona State
April 14, seminar talk at University of Maryland
June 15-19, invited speaker, "Interactions Between Hyperbolic Geometry, Quantum Topology and Number Theory ", Columbia University, New York
July 7-14, invited speaker, "Workshop on low-dimensional manifolds", East China Normal University, Shanghai, China
2008
March 13, 2008, invited speaker, topology seminar, Princeton University
April 25, 2008, colloquium speaker, Okalahoma State University.
May 13, 2008, invited speaker, bay area topology seminar, Univ. of California, Davis.
June 4, 2008, invited speaker, Mini-Symposia, IEEE International Conference on Shape Modeling and Applications , State University of New York, Stony Brook.
June 16-28, 2008, invited speaker, International workshop and conference on surface mapping class groups and related topics. Meghalaya, India.
June 30-July 11, 2008, Invited speaker, Transformation groups and orbifolds. Hangzhou, China
July 14-20, 2008, Invited speaker, Geometry of Teichmuller spaces and moduli spaces of curves. Hangzhou, China.
Sept. 11-13, 2008, invited speaker, Ricci flow in mathematics and physics , University of Strasbourg, France. my talk
2007
Jan. 8, 2007, AMS special session invited speaker. My talk " the cosine law and volume" . New Orleans, LA.
March. 15, 2007, colloquium speaker, Boston College, "rigidity of polyhedral surfaces" .
April 12-14, 2007, invited speaker, ASPECTS OF TEICHMUELLER THEORY, University of Michigan.
April 28-29, 2007, invited speaker, "Pacific Northwest Geometry Seminar" Univ. of Utah.
May 20-26, 2007, invited speaker, "BRAIDS AND THEIR RAMIFICATIONS" Cortona, Italy.
May 30-June 3, 2007, invited speaker, "A second time around the volume conjecture" Louisiana State University. .
June 18-22, 2007, speaker and co-organizer, "Geometric topology" Beijing, China .
June 25-30, 2007, speaker and co-organizer, Geometric topology and geometric analysis , CMS, Zhejiang University, Hangzhou, China.
July 16-20, 2007, invited speaker, "Discrete Differential Geometry" Berlin, Germany.
July 27-31, 2007, speaker and co-organizer, International Conference on Topology and Physics - In Memory of Xiao-Song Lin, Tianjin, China.
Oct. 20-21, invited speaker, "workshop on geometric evolution equations", UC San Diego.
Dec. 17-22, 2007, invited speaker, "The fourth International Congress of Chinese Mathematicians", Hangzhou, China.
2006
March 6-10, 2006, invited speaker, Oberwolfach workshop Discrete differential geometry. My talk "some applications of the cosine law" .
March 16-19, 2006, invited speaker (two lectures), Geometric Group Theory on the Gulf Coast.
May 17-21, 2006, invited speaker, Georgia Topology Conference .
Oct. 27-29, 2006, invited speaker, Texas Geometry and Topology Conference . My talk "volume and angle structures on 3-manifolds".