Weak weak approximation for certain quadric surface bundles

Abstract

We investigate weak approximation away from a finite set of places for a class of biquadratic fourfolds inside ${\mathbb{P}}^3\times {\mathbb{P}}^2$, some of which appear in the recent work of Hassett--Pirutka--Tschinkel.

Final version, to appear in Bulletin des Sciences Mathématiques