Back reaction and local cosmological expansion rate
By G. Geshnizjani, Robert Brandenberger. 2002
171 citations recorded by the source corpus.
We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter-dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/3ce51cc5756ea2a6acd4db9f08adca8b735dc345
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
- Yi Wang
- Robert Brandenberger
- Jérôme Martin
- S. Rasanen
- Stefan Nobbenhuis
- Xingang Chen
- Yi-Fu Cai
- T. Buchert
In Nuclear and High Energy Physics
- Jérôme Martin
- Robert Brandenberger
- Yi Wang
- S. Rasanen
- Stefan Nobbenhuis
- Yi-Fu Cai
- P. Peter
- Xingang Chen
Citations in the corpus
- Dark energy from backreaction (2003, background): “Indeed, the relation Ωde ≈ 2Ωcdm suggests a connection between dark energy and dark matter, and motivates the construction of models of unified, or coupled, dark matter and dark energy [10, 11, 12, 13, 14, 15, 16].”
- Trans-Planckian issues for inflationary cosmology (2012, background): “As conjectured in [116] and verified in [117, 118], in the case of purely adiabatic fluctuations (the energy densities of all components of matter being proportional) the leading IR back-reaction effect discussed above can be entirely absorbed by a second order time-reparametrization.”
- Categorizing Different Approaches to the Cosmological Constant Problem (2004, background): “Scalar-type Perturbations In [60, 61] the back-reaction for scalar gravitational perturbations is studied.”
- Inflation, Cosmic Perturbations and Non-Gaussianities (2013, background): “This is because at the non-linear level, the short wavelength fluctuations, which are accessible by local observers, can be mixed with long wavelength perturbations, which are not accessible by local observers (but still gauge invariant) [69, 70].”