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I received my Ph.D. from The Ohio State University in December 2012. My dissertation “Some topics concerning graphs, signed graphs, and matroids” was supervised by Prof. Neil Robertson. (I was his last (22) Ph.D. student.)

Research Interests: Graph Theory, Signed Graphs, Matroid Theory

Particular topics of interest include well-quasi-ordering, graph invariants (particularly chromatic number, Hadwiger number, girth), minor-closed classes of graphs, induced subgraphs, signed graphs, matroids coming from graphs, signed-graphic matroids, and statistical properties of matroids.


1. Two short proofs of the bounded case of S. B. Rao's degree sequence conjecture, Discrete Math. 313 (2013), no. 13, 1500-1501.
2. Bicircular signed-graphic matroids, Discrete Math. 328 (2014), 1–4.
3. A unified proof of Brooks’ theorem and Catlin’s theorem, Discrete Math. 338 (2015) no. 2, 272–273.
4. (with John Maharry, Neil Robertson, and Daniel Slilaty) Flexibility of projective-planar embeddings, J. Combin. Theory Ser. B 122 (2017), 241–300.
5. Some problems on induced subgraphs, Discrete Applied Mathematics, 236 (2018) 422-427.
6. (with Maria Chudnovsky) Odd holes in bull-free graphs, to appear in SIAM J. Disc. Math.
7. (with Richard Behr and Thomas Zaslavsky) Mock threshold graphs (under revision)
8. (with Maria Chudnovsky) Perfect divisibility and 2-divisibility, submitted.
9. Four NP-complete problems about generalizations of perfect graphs, submitted.
10. (with Bart Litjens, Sven Polak) Sum-perfect graphs, submitted.
11. (with Katie Cameron, Shenwei Huang, Irena Penev) The class of $(P_7, C_4, C_5)$-free graphs: decomposition, chi-boundedness, algorithms, submitted.


Current projects include understanding some hereditary classes of graphs, chi-boundedness, antivoltages in graphs, and the ubiquitous Tutte polynomial.


1. Signings of the Heawood graph.
2. On strongly regular graphs.
3. On a problem of Dijkstra.

In preparation:

1. (with Dan Slilaty) Antivoltages in groups of small order.
2. (with Ravindra Bapat, Richard Behr, and Thomas Zaslavsky) Smocks.


1. Neil Robertson
2. John Maharry
3. Daniel Slilaty
4. Maria Chudnovsky
5. Thomas Zaslavsky
6. Richard Behr
7. Bart Litjens
8. Sven Polak
9. Kathie Cameron
10. Shenwei Huang
11. Irena Penev
12. Lex Schrijver
13. Bart Sevenster

people/vaidy/research_page.txt · Last modified: 2018/03/17 07:22 by vaidy