MTW Ex 21.15 - Curvature independent of Lapse and Shift functions

TerryW
Gold Member
Messages
222
Reaction score
20
Homework Statement
I'm completely baffled as to where to start on this!
Relevant Equations
See attached image of MTW Ex 21.15
Can anyone out there give me a hint as to where to start with this problem?

I've been looking at it for a while and can't see a way forward.

What exactly is "the curvature itself" here?BTW I think the dynamic initial value equations 21.116 and 21.117 are incorrect. MTW should have inserted to ADM equivalents of these equations.

Any help would be appreciated.Regards
TerryW
Ex 21.15.png
 
Physics news on Phys.org
The best place to start with this problem is by understanding what the curvature itself is. Curvature is a measure of how much a surface or space is curved. It can be defined as the rate at which a line deviates from being straight. Once you understand what the curvature is, you can then begin to work on solving the dynamic initial value equations. You may find it helpful to review the ADM (Arnowitt–Deser–Misner) formalism, which is a set of equations used to describe the dynamics of curved spacetime in general relativity. This formalism can be used to solve the dynamic initial value equations. Additionally, you may find it helpful to consult other resources, such as textbooks or online tutorials, that provide more detailed solutions to the equations.
 
Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
The value of H equals ## 10^{3}## in natural units, According to : https://en.wikipedia.org/wiki/Natural_units, ## t \sim 10^{-21} sec = 10^{21} Hz ##, and since ## \text{GeV} \sim 10^{24} \text{Hz } ##, ## GeV \sim 10^{24} \times 10^{-21} = 10^3 ## in natural units. So is this conversion correct? Also in the above formula, can I convert H to that natural units , since it’s a constant, while keeping k in Hz ?

Similar threads

Back
Top