تقرير
$\Lambda(t)$ cosmology induced by a slowly varying Elko field
| العنوان: | $\Lambda(t)$ cosmology induced by a slowly varying Elko field |
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| المؤلفون: | Pereira, S. H., Pinho, S. S. A., da Silva, J. M. Hoff, Jesus, J. F. |
| المصدر: | JCAP01(2017)055 |
| سنة النشر: | 2016 |
| المجموعة: | Astrophysics General Relativity and Quantum Cosmology |
| مصطلحات موضوعية: | General Relativity and Quantum Cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics |
| الوصف: | In this work the exact Friedmann-Robertson-Walker equations for an Elko spinor field coupled to gravity in an Einstein-Cartan framework are presented. The torsion functions coupling the Elko field spin-connection to gravity can be exactly solved and the FRW equations for the system assume a relatively simple form. In the limit of a slowly varying Elko spinor field there is a relevant contribution to the field equations acting exactly as a time varying cosmological model $\Lambda(t)=\Lambda_*+3\beta H^2$, where $\Lambda_*$ and $\beta$ are constants. Observational data using distance luminosity from magnitudes of supernovae constraint the parameters $\Omega_m$ and $\beta$, which leads to a lower limit to the Elko mass. Such model mimics, then, the effects of a dark energy fluid, here sourced by the Elko spinor field. The density perturbations in the linear regime were also studied in the pseudo-Newtonian formalism. Comment: 15 pages, 4 figures; New section on evolution of density perturbations added |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/1475-7516/2017/01/055 |
| URL الوصول: | http://arxiv.org/abs/1608.02777 |
| رقم الأكسشن: | edsarx.1608.02777 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/1475-7516/2017/01/055 |
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