Non stable rationality of projective approximations for classifying spaces

TL;DR

This paper demonstrates numerous examples of non-stable rationality in projective approximations of classifying spaces, utilizing a new invariant and classical unramified cohomology techniques.

Contribution

It introduces new examples of non-stable rationality in the context of classifying spaces using innovative invariants and cohomological methods.

Findings

Multiple examples of non-stable rationality identified

Application of Benoit-Ottem invariant to classify rationality

Use of unramified cohomology to analyze projective approximations

Abstract

We give many examples of non stable rationalities for projective approximations of classifying spaces. Here we use the new invariant by Benoit-Ottem, and also use the classical unramified cohomology..