Details
| Original language | English |
|---|---|
| Article number | 016 |
| Journal | JCAP |
| Volume | 2022 |
| Issue number | 9 |
| Publication status | Published - 6 Sept 2022 |
| Externally published | Yes |
Abstract
The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in multi-field space. However, in many models, inflation does not end immediately after the enhancing feature and it is likely to continue with a second phase of slow-roll. We show that the resulting induced gravitational waves may probe the primordial spectrum from the second inflationary phase, even if its amplitude is too small to directly induce detectable gravitational waves. This is because, if there are sharp peaks in the primordial spectrum, the total gravitational wave spectrum is not simply the sum of gravitational waves induced by a peaked and scale-invariant primordial spectra separately, but cross terms from interaction between these modes also become important. We also find that such cross terms always have a characteristic slope. We discuss the parameter space that may be probed by future gravitational wave detectors in the presence of these signals.
Keywords
- gravitational waves / theory, inflation, physics of the early universe, primordial gravitational waves (theory)
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Astronomy and Astrophysics
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In: JCAP, Vol. 2022, No. 9, 016, 06.09.2022.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Induced gravitational waves from slow-roll inflation after an enhancing phase
AU - Balaji, Shyam
AU - Domènech, Guillem
AU - Silk, Joseph
N1 - Publisher Copyright: © 2022 IOP Publishing Ltd and Sissa Medialab.
PY - 2022/9/6
Y1 - 2022/9/6
N2 - The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in multi-field space. However, in many models, inflation does not end immediately after the enhancing feature and it is likely to continue with a second phase of slow-roll. We show that the resulting induced gravitational waves may probe the primordial spectrum from the second inflationary phase, even if its amplitude is too small to directly induce detectable gravitational waves. This is because, if there are sharp peaks in the primordial spectrum, the total gravitational wave spectrum is not simply the sum of gravitational waves induced by a peaked and scale-invariant primordial spectra separately, but cross terms from interaction between these modes also become important. We also find that such cross terms always have a characteristic slope. We discuss the parameter space that may be probed by future gravitational wave detectors in the presence of these signals.
AB - The primordial spectrum of fluctuations may present a large peak as a result of enhancing features during inflation. This may include, but is not limited to, bumps in the inflaton's potential, phases of ultra-slow-roll or turns in multi-field space. However, in many models, inflation does not end immediately after the enhancing feature and it is likely to continue with a second phase of slow-roll. We show that the resulting induced gravitational waves may probe the primordial spectrum from the second inflationary phase, even if its amplitude is too small to directly induce detectable gravitational waves. This is because, if there are sharp peaks in the primordial spectrum, the total gravitational wave spectrum is not simply the sum of gravitational waves induced by a peaked and scale-invariant primordial spectra separately, but cross terms from interaction between these modes also become important. We also find that such cross terms always have a characteristic slope. We discuss the parameter space that may be probed by future gravitational wave detectors in the presence of these signals.
KW - gravitational waves / theory
KW - inflation
KW - physics of the early universe
KW - primordial gravitational waves (theory)
UR - http://www.scopus.com/inward/record.url?scp=85138144548&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2022/09/016
DO - 10.1088/1475-7516/2022/09/016
M3 - Article
VL - 2022
JO - JCAP
JF - JCAP
IS - 9
M1 - 016
ER -