Timothy Sun
About Me
I recently received my PhD in Computer Science, advised by Xi Chen and Rocco Servedio in the Theory Group. As an undergrad, I was also at Columbia as a CS major. My senior thesis was advised by Jonathan Gross. I'm currently interested in graph theory and property testing.

In my spare time, I like to solve Rubik's Cube and related puzzles for speed. I used to compete actively. I've held six national titles and twelve continental records, and I won three bronze medals at the 2009 World Championships. I was part of the Columbia badminton club, serving as team captain from 2012-2019.

News
2019-05-12 I've added a tool for verifying the correctness of genus embeddings.
2019-04-23 Defended!
2018-01-12 I gave an invited talk "Face distributions of embeddings of complete graphs" at the Joint Mathematical Meetings in San Diego, CA.
Teaching
Spring 2018: COMS W4203: Graph Theory
Papers
Simultaneous constructions for minimum triangulations and complete graph embeddings
T. Sun, submitted
Jungerman ladders and index 2 constructions for genus embeddings of dense regular graphs
T. Sun, in preparation
A simple construction for orientable triangular embeddings of the complete graphs on 12s vertices
T. Sun, Discrete Mathematics 342(4) (2019) 1147-1151 [preprint]
Revisiting Mayer: Symmetric solutions for sporadic cases of the Map Color Theorem
T. Sun, manuscript
Face distributions of embeddings of complete graphs
T. Sun, submitted
Sample-based high-dimensional convexity testing
X. Chen, A. Freilich, R. Servedio, T. Sun, RANDOM 2017 [full version]
Deployable 3D Linkages With Collision Avoidance
C. Zheng, T. Sun, X. Chen, ACM/EG SCA 2016 (Best Paper Award)
Computational Design of Twisty Joints and Puzzles
T. Sun, C. Zheng, ACM SIGGRAPH (Proc. Trans. on Graphics) 2015
Fast Multipole Representation of Diffusion Curves and Points
T. Sun, P. Thamjaroenporn, C. Zheng, ACM SIGGRAPH (Proc. Trans. on Graphics) 2014
Genus distributions of cubic series-parallel graphs
J. L. Gross, M. Kotrbcik, T. Sun, DMTCS 16(3) (2014)
On Milgram's construction and the Duke embedding conjectures
T. Sun, senior thesis (advisor: Jonathan Gross)
Drawing some 4-regular planar graphs with integer edge lengths
T. Sun, 25th CCCG (2013)
Rigidity-theoretic constructions of integral Fary embeddings
T. Sun, 23rd CCCG (2011)
Tools
Heffter-Edmonds Face Tracer
Useful for computing the genus of moderately large rotation systems