# Francisco Santos Leal

**Francisco (Paco) Santos Leal** (born May 28, 1968) is a Spanish mathematician at the University of Cantabria, known for finding a counterexample to the Hirsch conjecture in polyhedral combinatorics.[1][2][3] In 2015 he won the Fulkerson Prize for this research.[4]

Santos was born in Valladolid, Spain.[5] He earned a licenciate in mathematics from the University of Cantabria in 1991, and a master's degree in pure mathematics from Joseph Fourier University in Grenoble, France in the same year.[5] He returned to Cantabria for his doctorate, which he finished in 1995, with a thesis on the combinatorial geometry of algebraic curves and Delaunay triangulations supervised by Tomás Recio.[6] He also has a second licenciate, in physics, from Cantabria in 1996. After postdoctoral studies at the University of Oxford he returned to Cantabria as a faculty member in 1997, and was promoted to full professor in 2008. From 2009 to 2013 he has been vice-dean of the Faculty of Sciences at Cantabria.[5]

As well as being honored by the Fulkerson Prize in 2015 for a counter-example of the Hirsch conjecture,[1][4] he was a semiplenary speaker at the 2006 International Congress of Mathematicians.[5]

Santos is an Editor-in-Chief of the Electronic Journal of Combinatorics.[7]

## References

- Santos, Francisco (2011), "A counterexample to the Hirsch conjecture",
*Annals of Mathematics*,**176**(1): 383–412, arXiv:1006.2814, doi:10.4007/annals.2012.176.1.7, MR 2925387 - "Francisco Santos encuentra un contraejemplo que refuta la conjetura de Hirsch",
*Gaussianos*, May 24, 2010 - Kalai, Gil (10 May 2010), "Francisco Santos Disproves the Hirsch Conjecture",
*Combinatorics and more*, retrieved 2015-07-18. - 2015 Fulkerson Prize citation, retrieved 2015-07-18.
- Curriculum vitae Archived 2016-04-16 at the Wayback Machine, retrieved 2015-07-18.
- Francisco Santos Leal at the Mathematics Genealogy Project
- "Editorial Team, Electronic Journal of Combinatorics". Retrieved 24 July 2015.