Uploaded June 2026 | Updated September 2026, 3 days ago
The 25th Midrasha Mathematicae on Groups, Expanders and Codes -- Celebrating Alex Lubotzky's 70th birthday.
Day 1, Session 2
Speaker: Ori Parzanchevski (HUJI)
Title: Ramanujan graphs - 40 years later
Abstract: Ramanujan regular graphs were defined and constructed in the 80’s by Margulis and Lubotzky-Phillips-Sarnak. In this talk we will survey generalizations of the notion of Ramanujan to general graphs and complexes, and describe some new constructions and applications to the cutoff mixing time.
The 25th Midrasha Mathematicae on Groups, Expanders and Codes -- Celebrating Alex Lubotzky's 70th birthday.
Day 1, Session 2
Speaker: Ori Parzanchevski (HUJI)
Title: Ramanujan graphs - 40 years later
Abstract: Ramanujan regular graphs were defined and constructed in the 80’s by Margulis and Lubotzky-Phillips-Sarnak. In this talk we will survey generalizations of the notion of Ramanujan to general graphs and complexes, and describe some new constructions and applications to the cutoff mixing time.
