- #1
robousy
- 334
- 1
Hi,
I have just read that one of the restrictions on [tex]T^{\mu\nu}[/tex] is that:
[tex]T^{\mu\nu}u^au^b > 0
[/tex]
where u is a timelike vector.
Can someone please tell me WHAT u actually is (other than saying it is a timelike vector).
What sort of vector is it, what is the context?
i.e Once I have obtained the stress energy tensor and I want to test the weak energy condition then what u's to I multiply it by to see if it is greater than zero?
Thanks!
I have just read that one of the restrictions on [tex]T^{\mu\nu}[/tex] is that:
[tex]T^{\mu\nu}u^au^b > 0
[/tex]
where u is a timelike vector.
Can someone please tell me WHAT u actually is (other than saying it is a timelike vector).
What sort of vector is it, what is the context?
i.e Once I have obtained the stress energy tensor and I want to test the weak energy condition then what u's to I multiply it by to see if it is greater than zero?
Thanks!