All Questions
7
questions
1
vote
0
answers
68
views
Calculation of the source term for the Einstein-Dirac equation in the weak field limit
I have seen the same being done for Einstein- Klein Gordon equations quite successfully. However, I'm struggling with it in the case of the E-D equations. I know that the einstein equations in the ...
- 63
-1
votes
1
answer
78
views
Gravitational energy and its conservation in quantum field theory
How does conservation of energy in quantum field theories reconcile with gravitational energy that is not modeled with quantum field theories? Does this mean that conservation of energy is only ...
6
votes
3
answers
552
views
Gravitational effect of negative energies in QFT
Within the formalism of QFT in curved space, we find negative energies to be unavoidable (theoretically). Even worse, all proposed Energy Conditions fail (in curved spacetime), not only within the ...
- 749
0
votes
1
answer
99
views
Are there mainstream quantum level physics models that use the idea of positive and negative energy balancing one another? [closed]
One interesting example of a mainstream cosmological physical model using the balancing of positive and negative energy is that of a charged black hole. Here, positive electromagnetic energy and ...
- 3,108
1
vote
0
answers
198
views
Relationship between generalized momentum and momentum operator in QFT
For each spacetime point $x$, we can define generalized momentum $\pi(x)$, where generalized coordinate is $\phi(x)$ (or quantum field). How is this generalized momentum related to actual momentum ...
- 389
5
votes
1
answer
720
views
Why is gravity sensitive to absolute energies?
In QFT absolute energies play no role in the physical set-up, only relative energies (i.e. energy differences) are important. However, in general relativity this doesn't appear to be the case, I've ...
- 3,063
35
votes
2
answers
10k
views
Energy-Momentum Tensor in QFT vs. GR
What is the correspondence between the conserved canonical energy-momentum tensor, which is $$ T^{\mu\nu}_{can} := \sum_{i=1}^N\frac{\delta\mathcal{L}_{Matter}}{\delta(\partial_\mu f_i)}\partial^\nu ...
- 2,024