Show that the center of a division ring is a field.
up vote
1
down vote
favorite
I tried the proof, but wasn't able to proceed further:
let a and b be any elements belonging to Z(center),
Now a.b=b.a
hence Z is commutative.
Now proving that Z is a division ring:(then we can show that since every commutative division ring is field, Z is a field)
NO CLUE...
abstract-algebra ring-theory
add a comment |
up vote
1
down vote
favorite
I tried the proof, but wasn't able to proceed further:
let a and b be any elements belonging to Z(center),
Now a.b=b.a
hence Z is commutative.
Now proving that Z is a division ring:(then we can show that since every commutative division ring is field, Z is a field)
NO CLUE...
abstract-algebra ring-theory
2
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
1
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I tried the proof, but wasn't able to proceed further:
let a and b be any elements belonging to Z(center),
Now a.b=b.a
hence Z is commutative.
Now proving that Z is a division ring:(then we can show that since every commutative division ring is field, Z is a field)
NO CLUE...
abstract-algebra ring-theory
I tried the proof, but wasn't able to proceed further:
let a and b be any elements belonging to Z(center),
Now a.b=b.a
hence Z is commutative.
Now proving that Z is a division ring:(then we can show that since every commutative division ring is field, Z is a field)
NO CLUE...
abstract-algebra ring-theory
abstract-algebra ring-theory
asked Nov 15 at 20:50
Cosmic
448
448
2
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
1
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08
add a comment |
2
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
1
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08
2
2
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
1
1
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08
add a comment |
1 Answer
1
active
oldest
votes
up vote
3
down vote
accepted
Hopefully you can already prove:
The center of a ring is a ring, in fact, a commutative ring.
Furthermore, if $D$ is a division ring, then for all $xin Z(D)$, if $xneq 0$, then $x^{-1}$ exists somewhere in $D$.
Now to show the commutative ring $Z(D)$ is a field, you'd have to show that $x^{-1}in Z(D)$, because inverses are unique, and a field necessarily has inverses for its nonzero elements.
So, the task is clear: if $0neq xin Z(D)$, prove $x^{-1}in Z(D)$.
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
accepted
Hopefully you can already prove:
The center of a ring is a ring, in fact, a commutative ring.
Furthermore, if $D$ is a division ring, then for all $xin Z(D)$, if $xneq 0$, then $x^{-1}$ exists somewhere in $D$.
Now to show the commutative ring $Z(D)$ is a field, you'd have to show that $x^{-1}in Z(D)$, because inverses are unique, and a field necessarily has inverses for its nonzero elements.
So, the task is clear: if $0neq xin Z(D)$, prove $x^{-1}in Z(D)$.
add a comment |
up vote
3
down vote
accepted
Hopefully you can already prove:
The center of a ring is a ring, in fact, a commutative ring.
Furthermore, if $D$ is a division ring, then for all $xin Z(D)$, if $xneq 0$, then $x^{-1}$ exists somewhere in $D$.
Now to show the commutative ring $Z(D)$ is a field, you'd have to show that $x^{-1}in Z(D)$, because inverses are unique, and a field necessarily has inverses for its nonzero elements.
So, the task is clear: if $0neq xin Z(D)$, prove $x^{-1}in Z(D)$.
add a comment |
up vote
3
down vote
accepted
up vote
3
down vote
accepted
Hopefully you can already prove:
The center of a ring is a ring, in fact, a commutative ring.
Furthermore, if $D$ is a division ring, then for all $xin Z(D)$, if $xneq 0$, then $x^{-1}$ exists somewhere in $D$.
Now to show the commutative ring $Z(D)$ is a field, you'd have to show that $x^{-1}in Z(D)$, because inverses are unique, and a field necessarily has inverses for its nonzero elements.
So, the task is clear: if $0neq xin Z(D)$, prove $x^{-1}in Z(D)$.
Hopefully you can already prove:
The center of a ring is a ring, in fact, a commutative ring.
Furthermore, if $D$ is a division ring, then for all $xin Z(D)$, if $xneq 0$, then $x^{-1}$ exists somewhere in $D$.
Now to show the commutative ring $Z(D)$ is a field, you'd have to show that $x^{-1}in Z(D)$, because inverses are unique, and a field necessarily has inverses for its nonzero elements.
So, the task is clear: if $0neq xin Z(D)$, prove $x^{-1}in Z(D)$.
answered Nov 15 at 22:23
rschwieb
103k1299238
103k1299238
add a comment |
add a comment |
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.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- 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.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3000309%2fshow-that-the-center-of-a-division-ring-is-a-field%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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
2
Take an element in the center and show its inverse is in the center too
– gd1035
Nov 15 at 20:51
I am sorry but, i am not getting how will it help?
– Cosmic
Nov 15 at 20:56
1
Z is a division ring if $zin$ Z $rightarrowexists yin$ Z such that $zy=1$, so you just need to take an arbitrary element in Z and show that its inverse is in Z
– gd1035
Nov 15 at 21:08