Talk:Spacetime symmetries

message: Ok, I created this page as another long term project. I've made a very sketchy start in writing something about symmetries in GR. I'm not sure if my description of preserving the metric is correct - in fact, now that I think about it, it's very loose. To rigorise the article, I was thinking of:
* Defining these symmetry vector fields in general and explaining why that definiton is a good one physically. 
* Defining some of the more important vector fields in relativity (and mechanics, I suppose) (Killing, homothetic, conformal etc.) - obviously, their physical interpretations should be stressed. 
*Maybe examples of spacetimes with certain symmetries should be stressed, along with conservation laws (e.g. Schwarzschild, Kerr and FRW are at least 3 obvious ones).
Mpatel 09:28, 10 Jun 2005 (UTC)
thread_title:  New page

message: Should have wrote this before I started doing it, but I'm making a conscious effort to start writing something substantial in this article. ---Mpatel 10:58, 16 Jun 2005 (UTC)
thread_title:  Conscious start on article 

message: I've changed the name of this article, as suggested by CH. --Mpatel 15:00, 21 July 2005 (UTC)
thread_title:  Name change 

message: I've included some more (interesting ?) info. on matter collineations. The perfect fluid example can be proven fairly easily by anyone who knows how to contract tensors. I'll get references for the electromagnetic 'results'; I think Hall's book has references for this. --Mpatel 15:21, 21 July 2005 (UTC)
thread_title: Matter collineations 

message: I wasn't sure if it was worth mentioning Ricci and Weyl collineations (\mathcal L_X R_{ab} =0 and \mathcal L_X C^a {}_{bcd}=0). Apart from the obvious preserving property of these tensors, I'm not sure if I can give much physical content. Not too sure about Ricci collineations (they're equivalent to matter collineations iff the Ricci scalar is zero or the vector field is Killing) - any obvious physics in there ? The Weyl tensor represents the gravitational field in regions where there is no matter, so preserving the Weyl tensor along an integral curve would mean ... ? Hmmm ... help ! --Mpatel 15:21, 21 July 2005 (UTC)
thread_title:  Ricci and Weyl collineations ? 

message: Anyone feel brave enough to create the article on conformal vector fields ? There is huge potential for creating such a great article, as gtrians (to borrow a phrase from CH) will know - links to pp-waves etc... --Mpatel 10:26, 28 July 2005 (UTC)
thread_title:  Conformals - if you dare ... 

message: It seems as though I'm talking to myself on this page...--Mpatel 10:29, 28 July 2005 (UTC)
replies: text: If I can only fix that thing I mentioned in email and take care of some other matters, I really do intend to try to read all this at greater length, write about physical interpretation and mathematical utility of some of these more exotic symmetries, etc.  Sorry for all these damnable delays! ---CH 01:18, 23 January 2006 (UTC)
thread_title:  Talking to myself ? 

message: The article is fairly mathematical. I realise that it needs a more intuitive description of spacetime symmetries. For example, there should be mention of Lorentz and general covariance and a brief description of what these mean. These ideas should then be related to (some of) the listed symmetries. Also, see the article symmetry in physics. MP   (talk) 14:02, 22 January 2006 (UTC)
thread_title:  Content of article 

message: Should this article also include discrete symmetries?  — Preceding unsigned comment added by 70.247.163.82 (talk) 00:27, 23 April 2016 (UTC)
thread_title:  Discrete Spacetime Symmetries?