On February 10, 2021, Jie Ma (马杰) from the University of Science and Technology of China gave an online talk at the Virtual Discrete Math Colloquium about the resolution of a conjecture of Boros, Caro, Füredi, and Yuster on the maximum number of edges in a 2-connected graph without two cycles of the same length. The title of his talk was “Non-repeated cycle lengths and Sidon sequences“.

## Jie Ma (马杰), Non-repeated cycle lengths and Sidon sequences

We prove a conjecture of Boros, Caro, Furedi and Yuster on the maximum number of edges in a 2-connected graph without repeated cycle lengths, which is a restricted version of a longstanding problem of Erdos. Our proof together with the matched lower bound construction of Boros, Caro, Furedi and Yuster show that this problem can be conceptually reduced to the seminal problem of finding the maximum Sidon sequences in number theory. Joint work with Tianchi Yang.