Structure formation in the Deser-Woodard nonlocal gravity model: a reappraisal
In this work, we extend previous analyses of the structure formation in the f ( ##IMG## [http://ej.iop.org/icons/Entities/square.gif] square −1 R ) model of nonlocal gravity proposed by Deser and Woodard (DW), which reproduces the background expansion of ΛCDM with no need of a cosmological constant...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
27 April 2017
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| In: |
Journal of cosmology and astroparticle physics
Year: 2017, Issue: 4, Pages: 1-11 |
| ISSN: | 1475-7516 |
| DOI: | 10.1088/1475-7516/2017/04/046 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1088/1475-7516/2017/04/046 Verlag, Volltext: http://stacks.iop.org/1475-7516/2017/i=04/a=046 
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| Author Notes: | Henrik Nersisyan, Adrian Fernandez Cid and Luca Amendola |
| Summary: | In this work, we extend previous analyses of the structure formation in the f ( ##IMG## [http://ej.iop.org/icons/Entities/square.gif] square −1 R ) model of nonlocal gravity proposed by Deser and Woodard (DW), which reproduces the background expansion of ΛCDM with no need of a cosmological constant nor of any dimensional constant beside Newton's one. A previous analysis based on redshift-space distortions (RSD) data concluded that the model was ruled out. In this work we revisit the issue and find that, when recast in a localized model, the DW model is not ruled out and actually gives a better fit to RSD data than ΛCDM. In fact, the DW model presents a suppressed growth of matter perturbations with respect to ΛCDM and a slightly lower value of σ 8 , as favored by observations. We also produce analytical approximations of the two modified gravity functions, i.e. the anisotropic stress η and the relative change of Newton's constant Y , and of f σ 8 ( z ) as a function of redshift. Finally, we also show how much the fit depends on initial conditions when these are generalized with respect to a standard matter-dominated era. |
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| Item Description: | Gesehen am 19.09.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1475-7516 |
| DOI: | 10.1088/1475-7516/2017/04/046 |