Scalar-induced gravitational waves in a ΛCDM cosmology
We reconsider the gravitational wave spectrum induced by scalar perturbations in spatially flat Friedmann-Lemaître-Robertson-Walker spacetimes, focusing on the matter- and Λ-dominated epochs. During matter domination, subhorizon modes are not free, and a commonly applied approximation for the deriv...
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| Hauptverfasser: | , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
24 March 2023
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| In: |
Physical review
Year: 2023, Jahrgang: 107, Heft: 6, Pages: 1-12 |
| ISSN: | 2470-0029 |
| DOI: | 10.1103/PhysRevD.107.063538 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevD.107.063538 Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevD.107.063538 
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| Verfasserangaben: | Marvin Sipp, Björn Malte Schäfer |
| Zusammenfassung: | We reconsider the gravitational wave spectrum induced by scalar perturbations in spatially flat Friedmann-Lemaître-Robertson-Walker spacetimes, focusing on the matter- and Λ-dominated epochs. During matter domination, subhorizon modes are not free, and a commonly applied approximation for the derivative of the tensor perturbation is flawed. We show analytically that this leads to a significant overestimation of the energy density spectrum. In addition, we demonstrate that gauge-dependent nonoscillating tensor perturbations appear in the presence of a cosmological constant. Complementing the analytical calculations, we compute the according present-day spectrum numerically for a Planck-like ΛCDM cosmology, finding that nonoscillating growing modes appear during the transition between matter and Λ domination in conformal Newtonian gauge. |
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| Beschreibung: | Gesehen am 24.05.2023 |
| Beschreibung: | Online Resource |
| ISSN: | 2470-0029 |
| DOI: | 10.1103/PhysRevD.107.063538 |