All Questions
Tagged with quantum-field-theory general-relativity
292
questions
2
votes
1
answer
158
views
Is there a general argument for why non-dynamical degrees of freedom show up in the propagation of massless gauge bosons?
In both spin-1 and spin-2 gauge theories, the gauge bosons (e.g. the photon & gluon and the graviton respectively) have two physical degrees of freedom, which can be observed quantum mechanically ...
- 858
1
vote
2
answers
152
views
Whether vacuum energy gravitate?
What is the relationship between vacuum energy and gravity, particularly in terms of gravitational effects and its contribution to the overall cosmological constant? Does vacuum energy possess ...
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
4
votes
1
answer
152
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Is quantization chart-dependent?
I have a bit of confusion because when doing QFT and QFT in curved spaces this particular issue seems to be avoided.
I have this feeling that when we quantize a theory, we somehow choose a chart and ...
3
votes
0
answers
123
views
One-loop gravity $\beta$ function
Gravity is renormalizable at one loop, see e.g. Why is GR renormalizable to one loop?
What is the one loop gravity $\beta$ function?
- 5,707
2
votes
0
answers
34
views
Generating Functional for Massless Spin 2 Particle
I'm trying to derive the generating functional for a massless, spin 2 field. However, I am getting a left over term that needs to go away. I'm working in de Donder gauge so that $\partial_\mu h^{\mu\...
- 41
3
votes
0
answers
193
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How do electrons interact with a graviton?
The spin of graviton is 2 and spin of electron is $\frac{1}{2}$. Of course, since electrons have mass, they pull each other in respect to gravitational force.
Whenever i tried to draw Feynman diagram ...
- 108
1
vote
0
answers
62
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Studying the Renormalizability of classically equivalent theories
I am currently studying the effect that a massive, uncharged, non-minimally coupled spin $\frac{1}{2}$ field has on the background geometry upon quantization, and compare this with results in General ...
- 353
7
votes
2
answers
1k
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How can the graviton be both massless and self-interacting?
Gravity is non-linear, so if it is mediated by gravitons, gravitons must interact with each other. On the other hand, the effects of gravity moves with the speed of light, so if it is mediated by ...
- 525
0
votes
0
answers
65
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Axiomatic Theories [duplicate]
In Number Theory and other areas of Pure Mathematics, whatever theorems we have are there forever because they are derived logically from a set of axioms. I would like to know which theories in ...
6
votes
2
answers
496
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Hawking Radiation without a horizon?
I’m reading this article for a straightforward derivation of the Hawking effect https://www.researchgate.net/publication/...
user310742
2
votes
0
answers
63
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QFTCS: Spacelike Surfaces in Different Coordinates for Comparing Vacuum
For a globally hyperbolic manifold $(M, g)$ we can always pose a well defined Cauchy problem through a foliation in terms of pairs $(t, \Sigma_t)$ where $t$ acts as a time-coordinate and $\Sigma_t$ is ...
- 136
6
votes
1
answer
558
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QFT on curved spacetime, uniqueness of spacelike hypersurface
Consider the Lagrangian of a real, scalar field coupled to gravity via the metric $g_{\mu\nu}$ and covariant derivative $\nabla_\mu$
$$\mathcal{L} = \sqrt{-g} (-\frac{1}{2} g^{\mu\nu} \nabla_\mu \phi \...
- 136
0
votes
1
answer
51
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Equivalent theories of general relativity and graviton spin
Are there equivalent theories of general relativity that assume a graviton has a spin-1?
- 31
-1
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1
answer
78
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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 ...
