All Questions
5
questions
4
votes
1
answer
209
views
Is gravitational particle production due to symmetry breaking?
A well-known fact about QFTs in curved spacetimes is that there is a phenomenon of particle production in expanding universes, these being described by the line element $$ds^2=-dt^2+b^2(t)d\vec x^2.$$
...
- 503
2
votes
1
answer
327
views
Fokker-Planck equation from Langevin equation in stochastic inflation
I'm reading this paper by Starobinsky and Yokoyama where they give the coarse-grained equation of motion,
$$
\dot{\bar{\phi}}({\bf x},t ) = -\frac{1}{3H}V'(\bar{\phi}) + f({\bf x},t)
$$
where $f({\bf ...
- 574
6
votes
1
answer
1k
views
In-in (Schwinger-Keldysh) formalism in cosmology
I'm working on some application of the Schwinger-Keldysh formalism in cosmology (studying correlation function during inflation).
I saw both the operator and the path integral approach, maybe ...
- 900
2
votes
1
answer
704
views
Main idea behind this paper on Closed-time-path functional formalism
I tried to understand following paper: Closed-time-path functional formalism in curved spacetime: Application to cosmological back-reaction problems but I can't understand what is going on because I ...
- 3,043
1
vote
1
answer
167
views
Two definitions: 'semi-classical space-time' and 'supersymmetric Minkowski space'
By reading articles I ran several times into two terms, never being defined so I assume they must have well established definitions somewhere.
The first is semi-classical space-time. If I where to ...
- 2,926