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arXiv · 2410.10742

The primordial non-Gaussianities for non-singular Horndeski cosmologies

Y. Ageeva·M. Kotenko·P. Petrov
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Abstract

We consider a novel Bounce Universe model constructed within the framework of Horndeski gravity. We have analyzed the bispectrum of primordial scalar perturbations and evaluated the corresponding non-Gaussianities for this specific model. The non-linear parameter $f_{\text{NL}}$ was computed for various wave vector configurations, including: (i) the local configuration, (ii) the equilateral configuration, and (iii) the enfolded configuration, which is a linear combination of the equilateral and orthogonal shapes. We demonstrate that the observational constraints on the scalar spectrum index tilt and the scalar-to-tensor ratio, together with the unitarity bounds, ensure that the bounds from non-Gaussianities are trivially satisfied. Therefore, this particular Bounce Universe scenario is fully viable in light of modern observational data.

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Y. Ageeva, M. Kotenko, P. Petrov. 2025-08-25. The primordial non-Gaussianities for non-singular Horndeski cosmologies. https://doi.org/10.1103/ghz6-w27b

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