I quote "no good way of defining global energy conservation", why is that?
I suggest reading the following text by John Baez: http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html
It is very well explained except the paragraph
"We will not delve into definitions of energy in general relativity such as the hamiltonian (amusingly, the energy of a closed universe always works out to zero according to this definition), various kinds of energy one hopes to obtain by "deparametrizing" Einstein's equations, or "quasilocal energy". There's quite a bit to say about this sort of thing! Indeed, the issue of energy in general relativity has a lot to do with the notorious "problem of time" in quantum gravity... but that's another can of worms."
(Already shared these references in a conversation with Torg yesterday - they may be useful to others too)
Take a look at this thread:
Tensor calculus is generally part of differential geometry. Spivak's book is the one I was trying to recall. Try a google search for:
Spivak, "Comprehensive Introduction to Differential Geometry"
For tensors: J.L. Synge, A. Schild, Tensor Calculus (e.g. Dover publ.)
I hope that helps.
Separate names with a comma.