Stress energy components as a 3 or 4 density?

  • #1
I usually come across expressions for the Stress energy tensor showing them as three densities (normally over a space-like slice.
In wikipedia's article on the spin tensor, they clearly (it does not appear to be an error) both write about and express the components of the stress energy tensor as four-densities. Is the three density just an approximation then?
For example:
06db8c0990a297671e457be2a9e4ba13.png

I usually come across this as an integral over three-space.
 

Answers and Replies

  • #2
Orodruin
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Gold Member
16,829
6,651
Wikipedia is wrong. In fact the statement itself makes no sense whatsoever. You cannot get momentum at time t if you have integrated t out!

Also, please note that it is customary (and required!) to link to your sources. Others should not have to go through the process of finding something you talk about to verify what you have said.
 
  • #3

Related Threads on Stress energy components as a 3 or 4 density?

  • Last Post
Replies
14
Views
6K
  • Last Post
Replies
2
Views
1K
Replies
3
Views
1K
Replies
2
Views
1K
Replies
11
Views
4K
Replies
4
Views
2K
Replies
4
Views
2K
Replies
4
Views
1K
Replies
45
Views
8K
  • Last Post
Replies
1
Views
2K
Top