Universal Bound on the Duration of a Kination Era
We show that primordial adiabatic curvature fluctuations generate an instability of the scalar field sourcing a kination era. We demonstrate that the generated higher Fourier modes constitute a radiationlike component dominating over the kination background after about 11 e-folds of cosmic expansion. Current constraints on the extra number of neutrino flavors ΔN_{eff} thus imply the observational bound of approximately 10 e-folds, representing the most stringent bound to date on the stiffness of the equation of state of the pre-Big Bang-nucleosynthesis universe.
Authors
- Cem Eröncel (ORCID: https://orcid.org/0000-0002-9308-1449)
- Peera Simakachorn (ORCID: https://orcid.org/0000-0002-4274-1179)
- Ryosuke Sato (ORCID: https://orcid.org/0000-0003-2745-4208)
- Yann Gouttenoire (ORCID: https://orcid.org/0000-0003-2225-6704)
- Géraldine Servant (ORCID: https://orcid.org/0000-0002-3063-363X)
Institutions
- Tel Aviv University (IL)
- Johannes Gutenberg University Mainz (DE)
- Parc Científic de la Universitat de València (ES)
- Deutsches Elektronen-Synchrotron DESY (DE)
- Istinye University (TR)
- Institute of Theoretical Physics (CN)
- The University of Osaka (JP)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-09-02
- DOI
- https://doi.org/10.1103/k7ty-gwjg
- Citations
- 5
- Primary Topic
- Cosmology and Gravitation Theories
- Type
- article
- Field-Weighted Citation Impact
- 5.77
Funders
- Deutsche Forschungsgemeinschaft
- Generalitat Valenciana
- Azrieli Foundation
- Japan Society for the Promotion of Science