Isotropy of Virtual Albert Forms over Function Fields of Quadrics

Let F be a field of characteristic different from 2 and let ϕ be a virtual Albert form over F , i.e., an anisotropic 6‐dimensional quadratic form over F which is still anisotropic over the field \documentclass{article}\pagestyle{empty}\begin{document}$F\left({\sqrt {d \pm \varphi } } \right).$\end{document} We give a complete description of the quadratic forms Ψ such that ϕ becomes isotropic over the function field F(Ψ). This completes the series of works ([H6], [Lag6], [Lag], [Lee], [M2]) where the question was considered previously.