Lenhard Lee Ng

Lenhard Ng
  • Eads Family Professor
  • Professor of Mathematics
External address: 216 Physics Bldg, 120 Science Drive, Durham, NC 27708
Internal office address: Box 90320, Durham, NC 27708-0320
Phone: (919) 660-6972
Office Hours: 

Fall 2018:

  • Mondays 2:00-3:00
  • Fridays 3:00-4:00

and by appointment.

Research Areas and Keywords

Geometry: Differential & Algebraic
symplectic geometry, contact geometry
Mathematical Physics
topological string theory
low-dimensional topology, knot theory

My research mainly focuses on symplectic topology and low-dimensional topology. I am interested in studying structures in symplectic and contact geometry (Weinstein manifolds, contact manifolds, Legendrian and transverse knots), especially through holomorphic-curve techniques. One particular interest is extracting topological information about knots through cotangent bundles, and exploring relations to topological string theory. I have also worked in Heegaard Floer theory, quantum topology, and sheaf theory, especially as they relate to Legendrian and transverse knots.

Education & Training
  • Ph.D., Massachusetts Institute of Technology 2001

Ng, L, and Rutherford, D. "Satellites of Legendrian knots and representations of the Chekanov-Eliashberg Algebra." Algebraic and Geometric Topology 13.5 (2013): 3047-3097. Full Text

Ekholm, T, Etnyre, J, Ng, L, and Sullivan, M. "Filtrations on the knot contact homology of transverse knots." Mathematische Annalen (2012): 1-31. Full Text

Ng, L. "On arc index and maximal Thurston-Bennequin number." Journal of Knot Theory and Its Ramifications 21.4 (2012).

Ng, L. "Combinatorial knot contact homology and transverse knots." Advances in Mathematics 227.6 (2011): 2189-2219. Full Text

Chongchitmate, W, and Ng, L. "An atlas of Legendrian knots (Accepted)." Experimental Mathematics (2011). (Academic Article)

Etnyre, J, Ng, L, and Vertesi, V. "Legendrian and transverse twist knots (Accepted)." Journal of the European Mathematical Society (2011). (Academic Article)

Khandhawit, T, and Ng, L. "A family of transversely nonsimple knots." Algebraic and Geometric Topology 10.1 (2010): 293-314. Full Text

Ng, L. "Rational symplectic field theory for Legendrian knots." Inventiones Mathematicae 182.3 (2010): 451-512. Full Text

Ng, L. "Framed knot contact homology." Duke Mathematical Journal 141.2 (2008): 365-406. Full Text

Lenhard, NG. "A skein approach to bennequin-type inequalities." International Mathematics Research Notices 2008.1 (2008). Full Text