I am a Marie Skłodowska-Curie Actions Global Fellow at Emory and Universität Hamburg.

Before that, I was a CRM-ISM Fellow at McGill working with Sergey Norin, and a postdoc of Benny Sudakov at ETH.

I did my Ph.D. jointly in Mathematics at University of Warwick and in Computer Science at Université Paris Diderot. My supervisors were Dan Kráľ and Jean Sébastien Sereni. The final version of my doctoral thesis can be found here.

I was a computer science student at the Faculty of Mathematics and Physics of Charles University in Prague.

There is also my Czech homepage.

**office:**Mathematics & Science Center, E421**e-mail:***jan [AT] ucw [DOT] cz*

- Extremal and probabilistic combinatorics
- Structural graph theory
- Ramsey theory

- Horizon 2020, MSCA Global Fellowship – QuasiHyp project
*(October 2018 - September 2021)*

- Math 350: Graph Theory and Combinatorics (Fall 2017)
- Math 350: Graph Theory and Combinatorics (Fall 2016)

- A. Grzesik, P. Hu, J. Volec:
*Minimum number of edges that occur in odd cycles*, to appear in Journal of Combinatorial Theory, Series B. The files needed for a verification of the proofs of Claims A.1 and B.1 are here. - D. Kráľ, S. Norin, J. Volec:
*A bound on the inducibility of cycles*, Journal of Combinatorial Theory, Series A**161**(2019), 359-363. - J. Balogh, P. Hu, B. Lidický, F. Pfender, J. Volec, M. Young:
*Rainbow triangles in three-colored graphs*, Journal of Combinatorial Theory, Series B**126**(2017), 83-113. - B. Sudakov, N. Kamčev, J. Volec:
*Bounded colorings of multipartite graphs and hypergraphs*, European Journal of Combinatorics**66**(2017), 235-249. - B. Sudakov, J. Volec:
*Properly colored and rainbow copies of graphs with few cherries*, Journal of Combinatorial Theory, Series B**122**(2017), 391-416. - J.-S. Sereni, J. Volec:
*A note on acyclic vertex-colorings*, Journal of Combinatorics**7**(2016), 725-737. - R. Glebov, D. Kráľ, J. Volec:
*A problem of Erdos and Sos on 3-graphs*, Israel Journal of Mathematics**211**(2016), 349-366. The files needed for a verification of the proof of Lemma 5 are here. - Z. Dvořák, J.-S. Sereni, J. Volec:
*Fractional coloring of triangle-free planar graphs*, The Electronic Journal of Combinatorics**22**(2015), #P4.11. - X. Goaoc, A. Hubard, R. de Joannis de Verclos, J.-S. Sereni, J. Volec:
*Limits of order types*, 31st International Symposium on Computational Geometry (SoCG 2015), Leibniz International Proceedings in Informatics (2015), 300-314. - J. Balogh, P. Hu, B. Lidický, O. Pikhurko, B. Udvari, J. Volec:
*Minimum number of monotone subsequences of length 4 in permutations*, Combinatorics, Probability and Computing**24**(2015), 658-679. - J. van den Heuvel, D. Kráľ, M. Kupec, J.-S. Sereni, J. Volec:
*Extensions of Fractional Precolorings show Discontinuous Behavior*, Journal of Graph Theory**77**(2014), 299-329. - Z. Dvořák, J.-S. Sereni, J. Volec:
*Subcubic triangle-free graphs have fractional chromatic number at most 14/5*, Journal of the London Mathematical Society**89**(2014), 641-662. - F. Kardoš, D. Kráľ, J. Volec:
*Maximum edge-cuts in cubic graphs with large girth and in random cubic graphs*, Random Structures and Algorithms**41**(2012), 506-520. The auxiliary files related to this paper are here. - D. Kráľ, M. Krnc, M. Kupec, B. Lužar, J. Volec:
*Extending fractional precolorings*, SIAM Journal on Discrete Mathematics**26**(2012), 647-660. - D. Kráľ, P. Škoda, J. Volec:
*Domination number of cubic graphs with large girth*, Journal of Graph Theory**69**(2012), 131-142. - O. Bílka, J. Jirásek, P. Klavík, M. Tancer, J. Volec:
*On the Complexity of Planar Covering of Small Graphs*, Proceedings 37 th Workshop on Graph-Theoretic Concepts in Computer Science 2011 (WG'11), Lecture Notes in Computer Science vol. 6986, pp. 83–94, Springer-Verlag, 2011. - F. Kardoš, D. Kráľ, J. Volec:
*Fractional colorings of cubic graphs with large girth*, SIAM Journal on Discrete Mathematics**25**(2011), 1454-1476.

- R. Glebov, D. Kráľ, J. Volec:
*Compactness and finite forcibility of graphons*, submitted. Preprint available as arXiv:1309.6695. - X. Goaoc, A. Hubard, R. de Joannis de Verclos, J.-S. Sereni, J. Volec:
*Limits of Order Types*, submitted. Preprint available as arXiv:1811.02236. - A. Blumenthal, B. Lidicky, R. Martin, S. Norin, F. Pfender, J. Volec:
*Counterexamples to a conjecture of Harris on Hall ratio*, submitted. Preprint available as arXiv:1811.11116.

- I organized Spring School on Combinatorics 2009, 2010 (both together with Dan Kráľ and Zuzka Patáková), and 2011 (together with Dan Kráľ and Tomáš Toufar).

- I was co-organising various leisure time activities and summer camps at the Youth Center for Prague 9 AKA Dům dětí a mládeže Prahy 9.
- I was a goalkeeper of Daytona B&W, playing 6-a-side league PKFL in Prague.

- Julian Alps (hike to Koča pri Triglavskih jezerih) + Škocjanská jama – June 2010
- Quarries Malá and Velká Amerika – July 2011
- High Tatras (hike to Priečne sedlo) – September 2011
- Julian Alps (hike to Triglav) – October 2011
- Snowdonia – March 2013
- Rocky Mountains – May 2013
- Vosges – March 2014
- Vosges – March 2014 #2