Noether's problems for groups of order 243

Huah Chu, Akinari Hoshi, Shou-Jen Hu +1

Let $k$ be any field, $G$ be a finite group. Let $G$ act on the rational function field $k(x_g:g\in G)$ by $k$-automorphisms defined by $h\cdot x_g=x_{hg}$ for any $g,h\in G$. Deno…