J. Korean Math. Soc. Published online February 4, 2021
Yun-Seong Ji, Myeong Jae Kim, and Byeong-Kweon Oh
Seoul National University
Abstract : A (positive definite integral) quadratic form is called even 2-universal if it represents all even quadratic forms of rank 2. In this article, we prove that there are at most 55 even 2-universal even quadratic forms of rank 5. The proofs of even 2-universalities of some candidates will be given so that exactly 20 candidates remain unproven.