arXiv subjects

Hanqing Long

Publications and source records attributed to Hanqing Long.

2 recordsLinked to original sources

arXiv2025

Degree 4 cohomological invariants of algebraic tori

In this paper, we determine the motive of the classifying torsor of an algebraic torus. As a result, we give an exact sequence describing the degree 4 cohomological invariants of algebraic tori. Using results by Blinstein and Merkurjev, this provides a formula for the degree 4 unramified cohomology group of an algebraic torus, via a flasque resolution.

math.AG↗

arXiv2022

The 3-rd unramified cohomology for norm one torus

For an algebraic torus $S$, Blinstein and Merkurjev have given an estimate of $3$-th unramified cohomology $\bar{H}^3_{nr}(F(S),\mathbb Q/\mathbb Z(2))$ obtained from a flasque resolution of $S$. Based on their work, for the norm one torus $W=R_{K/F}^{(1)}\mathbb{G}_m$ with $K/F$ abelian, we compute the $3$-th unramified cohomology $\bar{H}^3_{nr}(F(W),\mathbb Q/\mathbb Z(2))$.

math.NT↗