P-constrained not implies p-solvable
This article gives the statement and possibly, proof, of a non-implication relation between two group properties. That is, it states that every group satisfying the first group property (i.e., p-constrained group) need not satisfy the second group property (i.e., p-solvable group)
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Definition
It is possible to have a finite group and a prime number such that is a p-constrained group but not a p-solvable group.
Related facts
Converse
Opposite facts
Proof
Let be the wreath product of Z2 and A5 defined as the wreath product with base group cyclic group:Z2 and acting group alternating group:A5, where we use the natural permutation action of the acting group on a set of five elements. More explicitly, is the external semidirect product of elementary abelian group:E32 and alternating group:A5 where the latter acts on the former by coordinate permutations induced by the permutations on a set of five elements.
The group has order
Let .
We note that:
- is -constrained: Indeed, is trivial, and is the base of the semidirect product, i.e., a normal subgroup isomorphic to elementary abelian group:E32. In particular, this is contained in any -Sylow subgroup , so is also the normal subgroup that forms the base of the semidirect product. The subgroup is a self-centralizing normal subgroup, because it is an abelian normal subgroup and the induced action by the quotient is faithful. Thus, we get the condition .
- is not -solvable: For this, note that alternating group:A5, the simple non-abelian composition factor of , is neither a -group nor a -group.