Constraining the gravitational wave speed in the early Universe via gravitational Cherenkov radiation
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00638042" target="_blank" >RIV/68378271:_____/25:00638042 - isvavai.cz</a>
Result on the web
<a href="https://hdl.handle.net/11104/0375107" target="_blank" >https://hdl.handle.net/11104/0375107</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1088/1475-7516/2025/07/088" target="_blank" >10.1088/1475-7516/2025/07/088</a>
Alternative languages
Result language
angličtina
Original language name
Constraining the gravitational wave speed in the early Universe via gravitational Cherenkov radiation
Original language description
Scalar particles traveling faster than a subluminal gravitational wave generate gravitons via gravitational Cherenkov radiation. In this paper, we investigate graviton production by the primordial plasma within the framework of modified gravity in the early Universe, generating a relic graviton background. We find that for the minimal model, where only the speed of gravitational waves is modified and a standard model plasma minimally couples to gravity, the relic graviton background can be enhanced by several orders of magnitude, but still agrees with the Big Bang Nucleosynthesis (BBN) bound. Moreover, we also find that for Horndeski theories, such as Galileon theory, the relic background produced by the thermalized scalar field can reach significant amplitudes, exceeding the BBN bound for a region of the parameter space. By requiring the relic graviton background to remain consistent with the BBN constraint, we derive limits on the gravitational wave speed at early times in these modified gravity theories.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10303 - Particles and field physics
Result continuities
Project
<a href="/en/project/LUC23115" target="_blank" >LUC23115: Spin 2 WISPers from the laboratory to the cosmos</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Cosmology and Astroparticle Physics
ISSN
1475-7516
e-ISSN
1475-7516
Volume of the periodical
2025
Issue of the periodical within the volume
7
Country of publishing house
US - UNITED STATES
Number of pages
18
Pages from-to
088
UT code for WoS article
001542424800001
EID of the result in the Scopus database
2-s2.0-105011989604