Conversation started Dec 29, 2014 at 15:51.
Dec 29, 2014 15:51
Anyone here familiar with noncommutative ring theory?
2
Q: $P$ : prime ideal, $ R/P$ has no nilpotent elments. Then $R/P$ is integral domain.

GuillermoLet $P$ be a prime ideal. Suppose that $R/P$ has no nonzero nilpotent elments. Show that $R/P$ is integral domain. What I did : WTS : $(a+P)(b+P)=ab+P=0+P$ implies $a+P=0+P$ or $b+P=0+P$. but it means that $ab \in P$ implies $a \in P$ or $ b \in P$. The nilpotent condition means that $a \n...

Doesn't definition of integral domain usually include condition that ring is commutative?
I'm just wondering why you use term non-commutative.
Because we can define prime ideals a a non-commutative ring.
Oh, I'm not sure.
$R$ isn't necessarily an integral domain, but can $R/P$ be?
And isn't $R/P$ integral domain whenever $P$ is prime? In that case the condition about nilpotent elements is redundand.
That's true in a commutative ring.
For a non-commutative ring, doesn't the same proof show: If $P$ is prime then $R/P$ has no zero divisors?
Dec 29, 2014 16:01
The definition for prime in a non commutative ring causes the original proof not to work.
$P$ is prime if $AB \subseteq P$ then $A \subseteq P$ or $B \subseteq P$.
@user153330 This is just a personal theory: I think almost any human brain can be trained to excel in any field.
@RobertCardona Lam: Exercises in Classical Ring Theory, p.143; Exercise 10.3: Show that a ring R is a domain iff R is prime and reduced.
I guess this could help. (A proof is included there.)
Thanks!
That was a very nice trick!
why do we call Maxwell's equations on free space even if there exist charges and current??
I know that I musn't put this question here
Dec 29, 2014 16:10
Back to my work.
@BillDubuque Although I agree that poor users misuse "hint" style, it is very biased to talk about "obscure hints", or of a policy that "encourag[es] bad answers".
@RobertCardona Perhaps you can post an answer to that question. (It seems that you have thought about the details.)
@PedroTamaroff I do find many hints obscure, to the point where I wonder if they actually work.
Thanks! I will!
Maybe the answer does not have to be that detailed - you can always refer to Lam's book for the auxiliary result. (Or if you can find it somewhere else.)
Google returns some reasonably looking hits, like this blog.
Dec 29, 2014 16:15
@PedroTamaroff The point is not to argue that specific viewpoint, but to give an example of the many viewpoints, in particular one on the opposite end of the spectrum, (and held by a very talented teacher).
I wasn't familiar with the terminology: Reduced meant no nonzero nilpotent elements. So my searches didn't turn anything up :/
@RobertCardona What was your question?
@BillDubuque Be it of a talented professor or not, that quote is too biased to contribute anything to our discussion.
It actually wasn't an original question, I just came across it randomly
Dec 29, 2014 16:24
Hi
@RobertCardona Sorry for putting words in your mouth up there, but please use [text](link).
It's okay! I will next time!
 
Conversation ended Dec 29, 2014 at 16:25.