Sun Kai Leung

Multiplicative recurrence of Möbius transformations

Recurrence is a central theme in ergodic Ramsey theory. In this talk, I will present a complete characterization of multiplicative recurrence for images of the positive integers under Möbius transformations, answering a question of Donoso–Le–Moreira–Sun in the negative. If time permits, I will sketch a graph-theoretic proof, which is partially motivated by pretentious number theory. This is a joint work with Christian Táfula.