Prosolvable group

In

• Let p be a
  p-adic numbers
  , as usual, by ${\displaystyle \mathbf {Q} _{p}}$. Then the Galois group ${\displaystyle {\text{Gal}}({\overline {\mathbf {Q} }}_{p}/\mathbf {Q} _{p})}$, where ${\displaystyle {\overline {\mathbf {Q} }}_{p}}$ denotes the algebraic closure of ${\displaystyle \mathbf {Q} _{p}}$, is prosolvable. This follows from the fact that, for any finite Galois extension ${\displaystyle L}$ of ${\displaystyle \mathbf {Q} _{p}}$, the Galois group ${\displaystyle {\text{Gal}}(L/\mathbf {Q} _{p})}$ can be written as semidirect product ${\displaystyle {\text{Gal}}(L/\mathbf {Q} _{p})=(R\rtimes Q)\rtimes P}$, with ${\displaystyle P}$ cyclic of order ${\displaystyle f}$ for some ${\displaystyle f\in \mathbf {N} }$, ${\displaystyle Q}$ cyclic of order dividing ${\displaystyle p^{f}-1}$, and ${\displaystyle R}$ of ${\displaystyle p}$-power order. Therefore, ${\displaystyle {\text{Gal}}(L/\mathbf {Q} _{p})}$ is solvable.^[1]

See also

• Galois theory

References