Abstract

We apply the specialization technique based on the decomposition of the diagonal to the intersection of a quadric and cubic hypersurface in mathbb {P}^6. We find an explicit example defined over mathbb {Q} that is smooth, and does not admit a decomposition of the diagonal, and is therefore not retract rational. The proof uses the specialization of Nicaise and Ottem (Tropical degenerations and stable rationality, 2020), who proved that the very general complete intersection of this type is stably irrational using the motivic volume.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.