Zassenhaus Conjecture on torsion units holds for $\text{SL}(2,p)$ and $\text{SL}(2,p^2)$
Abstract
H.J. Zassenhaus conjectured that any unit of finite order and augmentation $1$ in the integral group ring $\mathbb{Z}G$ of a finite group $G$ is conjugate in the rational group algebra $\mathbb{Q}G$ to an element of $G$. We prove the Zassenhaus Conjecture for the groups $\text{SL}(2,p)$ and $\text{SL}(2,p^2)$ with $p$ a prime number. This is the first infinite family of non-solvable groups for which the Zassenhaus Conjecture has been proved. We also prove that if $G=\text{SL}(2,p^f)$, with $f$ arbitrary and $u$ is a torsion unit of $\mathbb{Z}G$ with augmentation $1$ and order coprime with $p$ then $u$ is conjugate in $\mathbb{Q}G$ to an element of $G$. By known results, this reduces the proof of the Zassenhaus Conjecture for this groups to prove that every unit of $\mathbb{Z}G$ of order multiple of $p$ and augmentation $1$ has actually order $p$.
- Publication:
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arXiv e-prints
- Pub Date:
- March 2018
- DOI:
- 10.48550/arXiv.1803.05342
- arXiv:
- arXiv:1803.05342
- Bibcode:
- 2018arXiv180305342D
- Keywords:
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- Mathematics - Group Theory
- E-Print:
- 13 pages, more general result with same methods. arXiv admin note: text overlap with arXiv:1608.05797