ciphergoth: (Default)
Paul Crowley ([personal profile] ciphergoth) wrote2002-03-06 10:12 am

Isomorphisms

For [livejournal.com profile] kitty_goth and [livejournal.com profile] gothslut, though others (eg [livejournal.com profile] ajva) may also be interested - a brief description of what I was going on about in the pub the other day. This is from "Sets and Groups", J A Green, Example 200.

In the ring R[X] of polynomials over the reals, consider the principal ideal J generated by the polynomial (X^2 + 1). Then the quotient ring R[X]/J is isomorphic to the field C of complex numbers: the map theta: C -> R[X]/J s.t. theta(a + bi) = a + bX + J is a ring-isomorphism.

rar

[identity profile] kitty-goth.livejournal.com 2002-03-06 02:40 am (UTC)(link)
That's one of those isomorphisms that I can just *see*

That rocks.

Re: rar

[identity profile] adjectivemarcus.livejournal.com 2002-03-06 04:05 am (UTC)(link)
Pshaw! I can just see it too. Understanding a fucking syllable of it, now that'd scare me.

Re: rar

[identity profile] ciphergoth.livejournal.com 2002-03-06 09:59 am (UTC)(link)
Would you like it if I explained?
zotz: (Default)

[personal profile] zotz 2002-03-06 05:16 am (UTC)(link)
Gesundheit.

[identity profile] pure-mourning.livejournal.com 2002-03-06 09:23 am (UTC)(link)
You know, I was just trying to explain the same thing to a friend of mine.

But I like your wording better :)

C
x

[identity profile] ciphergoth.livejournal.com 2002-03-06 09:56 am (UTC)(link)
This is the thing I found myself trying to explain to [livejournal.com profile] gothslut while we were in bed together. When I'd finished, she grabbed me and kissed me - so either she was trying to shut me up or quotient ring isomorphisms are sexy :-)

Re:

[identity profile] pure-mourning.livejournal.com 2002-03-06 10:18 am (UTC)(link)
While math does turn me on, as I'm sure it does everyone, I think it's more the raw intelligence part that's sexy and the way you boys sort of trail off into your own worlds while explaining something. I nearly broke into tears of love the time K so gently taught me html..

But I am a bit weird.

P.S. Add me so I can see you on my new journal/friends page ;) goth_christine is no more.

[identity profile] wechsler.livejournal.com 2002-03-06 11:42 am (UTC)(link)
Well she *did* wait for you to finish then... which probably says more about her patience than, erm, the stuff I didn't understand ;)
zz: (Default)

[personal profile] zz 2002-03-06 05:36 pm (UTC)(link)
if only my brain didn't automatically reject mathematical concepts it can't immediately visualise or see a use for.. :(

[identity profile] ladycat.livejournal.com 2002-03-09 07:22 am (UTC)(link)
I read this as "Sex & Groups"

I wonder if polynominals are related to polyamory ;p

Cat - who struggles with long divsion