English

Vari\'et\'es r\'eelles connexes non stablement rationnelles

Algebraic Geometry 2025-06-10 v2

Abstract

Let RR be the field of real Puiseux series. It is a real closed field. We construct the first examples of smooth intersections of two quadrics in PR5\mathbb{P}_R^5 and smooth cubic hypersurfaces in PR4\mathbb{P}_R^4 which are not stably rational but for which the space X(R)X(R) of RR-points is semi-algebraically connected. The question of constructing such examples over the field of real numbers R\mathbb{R} remains open.

Keywords

Cite

@article{arxiv.2505.21477,
  title  = {Vari\'et\'es r\'eelles connexes non stablement rationnelles},
  author = {Jean-Louis Colliot-Thélène and Alena Pirutka and Federico Scavia},
  journal= {arXiv preprint arXiv:2505.21477},
  year   = {2025}
}

Comments

34 pages, in French. Strengthened results in Section 6

R2 v1 2026-07-01T02:43:50.759Z