Power-laws f(R) theories are cosmologically unacceptable
In a recent paper,1 we have shown that f(R) = R + μRn modified gravity dark energy models are not cosmologically viable because during the matter era that precedes the accelerated stage the cosmic expansion is given by a ~ t1/2 rather than a ~ t2/3, where a is a scale factor and t is the cosmic time...
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| Hauptverfasser: | , , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
2007
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| In: |
International journal of modern physics
Year: 2007, Jahrgang: 16, Heft: 10, Pages: 1555-1561 |
| ISSN: | 1793-6594 |
| DOI: | 10.1142/S0218271807010936 |
| Online-Zugang: | Verlag, Volltext: http://dx.doi.org/10.1142/S0218271807010936 Verlag, Volltext: http://www.worldscientific.com/doi/abs/10.1142/S0218271807010936 
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| Verfasserangaben: | Luca Amendola, INAF/Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone, RM, Italy; David Polarski, Lab. de Physique Mathématique et Théorique, Université Montpellier II, UMR 5825, 34095 Montpellier Cedex 05, France; Shinji Tsujikawa, Department of Physics, Gunma National College of Technology, Gunma 371-8530, Japan |
| Zusammenfassung: | In a recent paper,1 we have shown that f(R) = R + μRn modified gravity dark energy models are not cosmologically viable because during the matter era that precedes the accelerated stage the cosmic expansion is given by a ~ t1/2 rather than a ~ t2/3, where a is a scale factor and t is the cosmic time. A recent work by Capozziello et al.2 criticized our results presenting some apparent counter-examples to our claim in f(R) = μRn models. We show here that those particular Rn models can produce an expansion as a ~ t2/3 but this does not connect to a late-time acceleration. Hence, though acceptable f(R) dark energy models might exist, the Rn models presented in Capozziello et al. are not cosmologically viable, confirming our previous results in Ref. 1. |
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| Beschreibung: | Gesehen am 15.11.2017 |
| Beschreibung: | Online Resource |
| ISSN: | 1793-6594 |
| DOI: | 10.1142/S0218271807010936 |