Understanding Notation in Hawking and Ellis: V_{(c;d)} and V_{[c;d]}

  • Context: Graduate 
  • Thread starter Thread starter robousy
  • Start date Start date
  • Tags Tags
    Notation
Click For Summary
SUMMARY

The discussion confirms the notation used in Hawking and Ellis regarding the symmetric and antisymmetric parts of a vector field, specifically V_{(c;d)} and V_{[c;d]}. The expressions are defined as V_{(c;d)} = \nabla_c V^d + \nabla_d V^c and V_{[c;d]} = \nabla_c V^d - \nabla_d V^c, with the symmetric part referred to as the symmetric part of V_{c;d} and the antisymmetric part potentially called the "curl" of V_c. Additionally, the combinatorial factor of 1/2! is noted as a convenient convention for these definitions.

PREREQUISITES
  • Understanding of differential geometry concepts, particularly covariant derivatives.
  • Familiarity with tensor notation and operations.
  • Knowledge of vector fields in the context of general relativity.
  • Basic comprehension of the works of Hawking and Ellis.
NEXT STEPS
  • Study the properties of covariant derivatives in differential geometry.
  • Explore the implications of symmetric and antisymmetric tensors in physics.
  • Learn about the role of curl in vector calculus and its applications in physics.
  • Read further into the works of Hawking and Ellis, focusing on their treatment of tensor analysis.
USEFUL FOR

Students and researchers in theoretical physics, particularly those focusing on general relativity, differential geometry, and tensor analysis. This discussion is also beneficial for anyone seeking to clarify notation in advanced mathematical physics texts.

robousy
Messages
332
Reaction score
1
Hey, I'm going through Hawking and Ellis and want to confirm I have understood some notation correctly.

Are the following correct?

[tex]V_{(c;d)}=\nabla_c V^d + \nabla_d V^c[/tex]

and

[tex]V_{[c;d]}=\nabla_c V^d - \nabla_d V^c[/tex]

Also, do these have specific names?

Thanks in advance!

Richard
 
Last edited:
Physics news on Phys.org
robousy said:
Hey, I'm going through Hawking and Ellis and want to confirm I have understood some notation correctly.

Are the following correct?

[tex]V_{(c;d)}=\nabla_c V^d + \nabla_d V^c[/tex]

and

[tex]V_{[c;d]}=\nabla_c V^d - \nabla_d V^c[/tex]

Also, do these have specific names?

Thanks in advance!

Richard


[tex]V_{(c;d)}=\frac{1}{2!} \left( \nabla_d V_c + \nabla_c V_d \right)[/tex]

and

[tex]V_{[c;d]}=\frac{1}{2!}\left( \nabla_d V_c - \nabla_c V_d \right)[/tex]

The combinatorial factor is a convenient convention.
With it, you can call these the symmetric and antisymmetric parts of [tex]V_{c;d}[/tex].
You could call the antisymmetric part the "curl" of [tex]V_c[/tex].


Note that the operation
[tex]{(something)}_{;d}[/tex] is the same as [tex]\nabla_d (something)[/tex]
 
Ok Rob! Thanks a lot for clarifying that for me. Very much appreciated.

:smile:
 

Similar threads

  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 55 ·
2
Replies
55
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
6
Views
3K
  • · Replies 36 ·
2
Replies
36
Views
5K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 30 ·
2
Replies
30
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K