Teaching:

• Calculus
• Discrete Mathematics
• Linear Algebra
• Numerical Computations and Analysis
• Probability and Statistics
• Math for Education

Research Topics:

• Paths and Cycles in Digraphs
• Second Neighborhood in Digraphs
• Out-Domination in Tournaments
• Packing Coloring of Graphs

Selected publications:

• Zein, A.E., 2022. Oriented Hamiltonian Cycles in Tournaments: a Proof of Rosenfeld’s Conjecture. arXiv preprint arXiv:2204.11211.
• Zein, A.E., 2022. About Out-Domination in Tournaments. arXiv preprint
• Zein, A.E., 2022. Long Paths in n-Chromatic Digraphs. arXiv preprint
• Zein, A.E., 2022. The Second Neighborhood for Digraphs with Large Degree. arXiv preprint

Biography

Ayman El Zein received the bachelor in pure mathematics from the Lebanese University, Hadat, 2018, the Masters degree in discrete mathematics and algebra from the Lebanese University, Hadat, 2020, and the Ph.D degree in mathematics from the Lebanese University, Hadat and Université Savoie Mont Blanc, Chambéry, France, in 2023. In 2018, he won the first-place award in LAU Mathematics Tournament. In 2021, he was the first to solve Rosenfeld’s Cycles Conjecture proposed in 1974. Currently, he is assistant professor at the University of Sciences and Arts in Lebanon (USAL). His research interests are in Graph Theory: Universal Graphs, Second Neighborhood in Digraphs, Out-Domination in Tournaments, and Packing Coloring of Graphs.