Semi-colon vs nabla notation

  • Thread starter pellman
  • Start date
  • #1
pellman
684
5
Is it

[tex]\nabla_\mu\nabla_\nu A^\alpha={A^\alpha}_{;\mu\nu}[/tex]

or

[tex]\nabla_\mu\nabla_\nu A^\alpha={A^\alpha}_{;\nu\mu}[/tex]

?
 

Answers and Replies

  • #2
dextercioby
Science Advisor
Homework Helper
Insights Author
13,223
861
The second is the right one.

[tex] \nabla_\mu \nabla_\nu A^\alpha=\left(A^{\alpha}_{~;\nu}\right)_{;\mu}= A^{\alpha}_{~;\nu;\mu} = A^{\alpha}_{~;\nu\mu} [/tex]

To avoid errors, my suggestion is not to use them both at the same time when making calculations.
 
  • #3
CompuChip
Science Advisor
Homework Helper
4,306
49
This is one reason I prefer the nabla-notation. (Another is that I often get confused afterwards whether I that little dot over the comma is just a little ink drop or I actually meant to write a semi-colon.)
 
  • #4
pellman
684
5
Thanks!
 

Suggested for: Semi-colon vs nabla notation

  • Last Post
Replies
6
Views
13K
  • Last Post
Replies
9
Views
1K
  • Last Post
Replies
1
Views
533
Replies
5
Views
1K
  • Last Post
Replies
4
Views
937
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
16
Views
4K
  • Last Post
Replies
16
Views
1K
Top