تقرير
Alternatives to $\Lambda$: Torsion, Generalized Couplings, and Scale Invariance
| العنوان: | Alternatives to $\Lambda$: Torsion, Generalized Couplings, and Scale Invariance |
|---|---|
| المؤلفون: | Martins, C. J. A. P., Marques, C. M. J., Fernandes, C. B. D., Oliveira, J. S. J. S., Pinheiro, D. A. R., Rocha, B. A. R. |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology |
| مصطلحات موضوعية: | Astrophysics - Cosmology and Nongalactic Astrophysics, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology |
| الوصف: | We present a comparative analysis of current observational constraints on three recently discussed alternative models for explaining the low-redshift acceleration of the universe: the so-called steady-state torsion model, the generalized coupling model, and the scale invariant model by Maeder (an example of a broader class which we also briefly study) These are compared to the traditional parameterization of Chevallier, Polarski and Linder. Each of the candidate models is studied under two different assumptions: as genuine alternatives to $\Lambda$CDM (where a new degree of freedom would be expected to explain the recent acceleration of the universe without any cosmological constant) and as parametric extensions of $\Lambda$CDM (where both a cosmological constant and the new mechanism can coexist, and the relative contributions of both are determined by the data). Our comparative analysis suggests that, from a phenomenological point of view, all such models neatly divide into two classes, with different observational consequences. Comment: Summary of a talk given at the Theories of Gravity: Alternatives to the Cosmological and Particle Standard Models parallel session of the Sixteenth Marcel Grossmann Meeting, partially summarizing work previously reported in arXiv:1911.08232 and arXiv:2012.10513. To appear in the proceedings |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2111.08086 |
| رقم الأكسشن: | edsarx.2111.08086 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |