The two-isogeny descent quartics associated with square classes and on have no rational points. A rational solution can be scaled to integral with coprime integers . If is odd, reduction modulo sixteen gives or for the positive class, and or for the negative class; none is a quadratic residue. If is even, then is odd and the right side is , with the same sign on the two signed terms. The bracket is odd, so its 2-adic valuation is exactly five, impossible for a nonzero square. These two parity cases exhaust primitive solutions.
Articles by others on the same topic
There are currently no matching articles.