Very honorable with congratulations of the jury!
PhD thesis defense of Ayman El Zein at the Lebanese University, under the direction of Prof. Amine El Sahili, Dr. Karim Nour and Dr. Maidoun Mortada, with "VERY HONORABLE" grade.
Thesis title: "About Cycles and Out-Domination in Tournaments and Rewriting on Trees"
Besides other interesting and valuable results in graph theory, Ayman proved and for the first time the Rosenfeld's conjecture proposed in 1974, which states that there is an integer N > 8, such that every tournament of order n > N contains every non-directed cycle of order n.
More precisely, in his thesis, Ayman proved that with exactly 35 exceptions, every tournament of order n > 2 contains each non-directed cycle of order m, 2 < m < n+1.
Congratulations!!!
