# Lenhard Lee 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:**

Spring 2018:

- Mondays 2:00-3:00
- Thursdays 11:00-12:00

and by appointment.

### Research Areas and Keywords

##### Geometry: Differential & Algebraic

##### Mathematical Physics

##### Topology

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.

Ng, LL. "Hamiltonian Decomposition of Lexicographic Products of Digraphs." *Journal of Combinatorial Theory. Series B* 73.2 (1998): 119-129.
Full Text

Kedlaya, KS, and Ng, LL. "The rook on the half-chessboard, or how not to diagonalize a matrix." *American Mathematical Monthly* 105.9 (1998): 819-824.

Ng, LL. "Hamiltonian decomposition of complete regular multipartite digraphs." *Discrete Mathematics* 177.1-3 (1997): 279-285.

Ng, L, and Schultz, M. "k-Ordered Hamiltonian Graphs." *Journal of Graph Theory* 24.1 (1997): 45-57.

Ng, L. "Plane curves and contact geometry." *Proceedings of G\~A{\P}kova Geometry-Topology Conference 2005
(2006), 165-174*.

Ng, LL. "The Legendrian satellite construction." *Appears as part of"Legendrian solid-torus links", J. Symplectic
Geom. 2 (2005), No. 3, 411-443*.

Ng, L. "Conormal bundles, contact homology and knot invariants." *Geom. Topol. Monogr.* 8: 129-144.
Full Text

Ng, L, and Thurston, D. "Grid Diagrams, Braids, and Contact Geometry." *Proceedings of Gokova Geometry-Topology Conference 2008, 120--136*.

Ng, L, Rutherford, D, Shende, V, Sivek, S, and Zaslow, E. "Augmentations are Sheaves (Submitted)." Open Access Copy