There are no universal ternary quadratic forms over biquadratic fields

Jakub Krásenský, Magdaléna Tinková, Kristýna Zemková

We study totally positive definite quadratic forms over the ring of integers ${\mathcal{O}}_K$ of a totally real biquadratic field $K=\mathbb{Q}(\sqrt{m},\sqrt{s})$. We restrict our…