A. Yamasaki

activity

20152019

collaborators

4 papers

math.AG2019

An application of cohomological invariants

Akinari Hoshi, Ming-chang Kang, Aiichi Yamasaki

Let $G$ be a finite group, $k$ be a field and $G \to G L (V_{reg})$ be the regular representation of $G$ over $k$ . Then $G$ acts naturally on the rational function field $k(V_{\rm…

math.AG2018

Rationality problem for norm one tori in small dimensions

Sumito Hasegawa, Akinari Hoshi, Aiichi Yamasaki

We classify stably/retract rational norm one tori in dimension $n - 1$ for $n = 2^{e}$ $(e \geq 1)$ is a power of $2$ and $n = 12, 14, 15$ . Retract non-rationality of norm one tori for prim…

math.AG2018

Rationality problem for norm one tori

Akinari Hoshi, Aiichi Yamasaki

We classify stably/retract rational norm one tori in dimension $p - 1$ where $p$ is a prime number and in dimension up to ten with some minor exceptions.

math.AG2015

Degree Three Unramified Cohomology Groups

Akinari Hoshi, Ming-chang Kang, Aiichi Yamasaki

Let $p$ be an odd prime number. Peyre shows that there is a group $G$ of order $p^{12}$ such that $H_{n r}^{3} (C (G), Q / Z)$ is non-trivial. Using Peyre's method, we are…