: 16h00, ngày 23/12/2022 (Thứ Sáu)
: P104 D3
: Seminar Toán rời rạc
: Nguyễn Duy Tân
: Viện Toán ứng dụng và Tin học, ĐH Bách Khoa Hà Nội
Tóm tắt báo cáo
Classically, for each prime number p, we can construct the corresponding Paley graph using quadratic and non-quadratic residues modulo p. In this talk, we discuss generalized Paley graphs. These are graphs that are associated with a general quadratic character. We will provide some of their basic properties. In particular, we describe their spectrum explicitly and use them to construct some new families of Ramanujan graphs. Time permitting, we will provide an effective upper bound for the Cheeger number of these generalized Paley graphs.