If $G'=G$, and suppose $N_G(P)$ is solvable for $Psubseteq G$, show that $ G$ is simple.












1












$begingroup$


Given a finite nontrivial group $G$, Suppose $N_G(P)$ is solvable for every nontrivial $Psubseteq G$ of prime power order. If $G'=G$, (where $G'$ is the derived subgroup) show that $G$ is simple.



I understand the pieces of information given in the problem but how to put them together to make an argument is challenging to me. I will appreciate any help.



I am thinking that, if I start by assuming $G$ is not simple and that there exists a normal nontrivial subgroup $ Ntriangleleft G$.



And if I can show that the commutator subgroup $G'=1$ then since $G'=G$ I get a contradiction to the nontriviality assumption of the group.



Is this a good way to go? How should I view it?
Thanks










share|cite|improve this question











$endgroup$








  • 3




    $begingroup$
    Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
    $endgroup$
    – Derek Holt
    Dec 4 '18 at 10:05










  • $begingroup$
    @DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
    $endgroup$
    – Cnine
    Dec 5 '18 at 23:08










  • $begingroup$
    That's the second isomorphism theorem
    $endgroup$
    – Derek Holt
    Dec 6 '18 at 8:08
















1












$begingroup$


Given a finite nontrivial group $G$, Suppose $N_G(P)$ is solvable for every nontrivial $Psubseteq G$ of prime power order. If $G'=G$, (where $G'$ is the derived subgroup) show that $G$ is simple.



I understand the pieces of information given in the problem but how to put them together to make an argument is challenging to me. I will appreciate any help.



I am thinking that, if I start by assuming $G$ is not simple and that there exists a normal nontrivial subgroup $ Ntriangleleft G$.



And if I can show that the commutator subgroup $G'=1$ then since $G'=G$ I get a contradiction to the nontriviality assumption of the group.



Is this a good way to go? How should I view it?
Thanks










share|cite|improve this question











$endgroup$








  • 3




    $begingroup$
    Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
    $endgroup$
    – Derek Holt
    Dec 4 '18 at 10:05










  • $begingroup$
    @DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
    $endgroup$
    – Cnine
    Dec 5 '18 at 23:08










  • $begingroup$
    That's the second isomorphism theorem
    $endgroup$
    – Derek Holt
    Dec 6 '18 at 8:08














1












1








1





$begingroup$


Given a finite nontrivial group $G$, Suppose $N_G(P)$ is solvable for every nontrivial $Psubseteq G$ of prime power order. If $G'=G$, (where $G'$ is the derived subgroup) show that $G$ is simple.



I understand the pieces of information given in the problem but how to put them together to make an argument is challenging to me. I will appreciate any help.



I am thinking that, if I start by assuming $G$ is not simple and that there exists a normal nontrivial subgroup $ Ntriangleleft G$.



And if I can show that the commutator subgroup $G'=1$ then since $G'=G$ I get a contradiction to the nontriviality assumption of the group.



Is this a good way to go? How should I view it?
Thanks










share|cite|improve this question











$endgroup$




Given a finite nontrivial group $G$, Suppose $N_G(P)$ is solvable for every nontrivial $Psubseteq G$ of prime power order. If $G'=G$, (where $G'$ is the derived subgroup) show that $G$ is simple.



I understand the pieces of information given in the problem but how to put them together to make an argument is challenging to me. I will appreciate any help.



I am thinking that, if I start by assuming $G$ is not simple and that there exists a normal nontrivial subgroup $ Ntriangleleft G$.



And if I can show that the commutator subgroup $G'=1$ then since $G'=G$ I get a contradiction to the nontriviality assumption of the group.



Is this a good way to go? How should I view it?
Thanks







abstract-algebra group-theory finite-groups






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 4 '18 at 9:39









the_fox

2,58711533




2,58711533










asked Dec 4 '18 at 9:13









CnineCnine

895




895








  • 3




    $begingroup$
    Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
    $endgroup$
    – Derek Holt
    Dec 4 '18 at 10:05










  • $begingroup$
    @DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
    $endgroup$
    – Cnine
    Dec 5 '18 at 23:08










  • $begingroup$
    That's the second isomorphism theorem
    $endgroup$
    – Derek Holt
    Dec 6 '18 at 8:08














  • 3




    $begingroup$
    Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
    $endgroup$
    – Derek Holt
    Dec 4 '18 at 10:05










  • $begingroup$
    @DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
    $endgroup$
    – Cnine
    Dec 5 '18 at 23:08










  • $begingroup$
    That's the second isomorphism theorem
    $endgroup$
    – Derek Holt
    Dec 6 '18 at 8:08








3




3




$begingroup$
Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
$endgroup$
– Derek Holt
Dec 4 '18 at 10:05




$begingroup$
Choose $P in {rm Syl}_p(N)$ for some prime $p$ dividing $N$. Then by the Frattini Argument $G = NN_G(P)$ and $G/N cong N_G(P)/N_N(P)$. Now use the facts that $N_G(P)$ is solvable and $G'=G$ to deduce that $G=N$.
$endgroup$
– Derek Holt
Dec 4 '18 at 10:05












$begingroup$
@DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
$endgroup$
– Cnine
Dec 5 '18 at 23:08




$begingroup$
@DerekHolt, thank you. but why is $G/N=N_G(P)/N_N(P)$.?
$endgroup$
– Cnine
Dec 5 '18 at 23:08












$begingroup$
That's the second isomorphism theorem
$endgroup$
– Derek Holt
Dec 6 '18 at 8:08




$begingroup$
That's the second isomorphism theorem
$endgroup$
– Derek Holt
Dec 6 '18 at 8:08










0






active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3025326%2fif-g-g-and-suppose-n-gp-is-solvable-for-p-subseteq-g-show-that-g-i%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3025326%2fif-g-g-and-suppose-n-gp-is-solvable-for-p-subseteq-g-show-that-g-i%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Quarter-circle Tiles

build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

Mont Emei