Étale Homotopy Obstructions of Arithmetic Spheres

Edo Arad, Shachar Carmeli, Tomer M. Schlank

Let $K$ be a field of characteristic $\ne 2$ and let $X$ be the affine variety over $K$ defined by the equation $$X:a_0{x}_0^2+\cdots +a_n{x}_n^2=1$$ where $n\ge 0$ and $a_i\i…