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N-body simulations with a cosmic vector for dark energy

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López Maroto, Antonio and Beltrán Jimenez, Jose and Gottloeber, Stefan and Yepes Alonso, Gustavo and Knebe, Alexander and Carlesi, Edoardo (2012) N-body simulations with a cosmic vector for dark energy. Monthly Notices of the Royal Astronomical Society, 424 (1). pp. 699-715. ISSN 0035-8711

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Official URL: http://dx.doi.org/10.1111/j.1365-2966.2012.21258.x




Abstract

We present the results of a series of cosmological N-body simulations of a vector dark energy (VDE) model, performed using a suitably modified version of the publicly available gadget-2 code. The set-ups of our simulations were calibrated pursuing a twofold aim: (1) to analyse the large scale distribution of massive objects and (2) to determine the properties of halo structure in this different framework. We observe that structure formation is enhanced in VDE, since the mass function at high redshift is boosted up to a factor of 10 with respect to ? cold dark matter ( CDM), possibly alleviating tensions with the observations of massive clusters at high redshifts and early reionization epoch. Significant differences can also be found for the value of the growth factor, which in VDE shows a completely different behaviour, and in the distribution of voids, which in this cosmology are on average smaller and less abundant. We further studied the structure of dark matter haloes more massive than 5 x 1013 h-1 M?, finding that no substantial difference emerges when comparing spin parameter, shape, triaxiality and profiles of structures evolved under different cosmological pictures. Nevertheless, minor differences can be found in the concentrationmass relation and the two-point correlation function, both showing different amplitudes and steeper slopes. Using an additional series of simulations of a ?CDM scenario with the same and s8 used in the VDE cosmology, we have been able to establish whether the modifications induced in the new cosmological picture were due to the particular nature of the dynamical dark energy or a straightforward consequence of the cosmological parameters. On large scales, the dynamical effects of the cosmic vector field can be seen in the peculiar evolution of the cluster number density function with redshift, in the shape of the mass function, in the distribution of voids and on the characteristic form of the growth index (z). On smaller scales, internal properties of haloes are almost unaffected by the change of cosmology, since no statistical difference can be observed in the characteristics of halo profiles, spin parameters, shapes and triaxialities. Only halo masses and concentrations show a substantial increase, which can, however, be attributed to the change in the cosmological parameters.


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© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
We would like to thank Juan Garcia-Bellido for his interesting suggestions and discussions. EC is supported by the MareNostrum project funded by the Spanish Ministerio de Ciencia e Innovacion (MICINN) under grant no. AYA2009-13875 C03-02 and MultiDark Consolider project under grant CSD2009 00064. AK acknowledges support by the MICINN's Ramon y Cajal programme as well as the grants AYA 2009-13875-C03 02, AYA2009 12792-C03-03, CSD2009-00064 and CAM S2009/ESP 1496. GY would like to thank the MICINN for financial support under grants AYA 2009-13875-C03 and FPA 2009-08958, and the SyeC Consolider project CSD2007 00050. JBJ is supported by the Ministerio de Educacion under the postdoctoral contract EX2009-0305 and also wishes to acknowledge support from the Norwegian Research Council under the YGGDRASIL programme 2009 2010 and the NILS mobility project grant UCM-EEA-ABEL-03-2010. We also acknowledge support from MICINN (Spain) project numbers FIS 2008-01323, FPA 2008-00592, CAM/UCM 910309 and FIS2011 23000. The simulations used in this work were performed in the MareNostrum supercomputer at Barcelona Supercomputing Center (BSC).

Uncontrolled Keywords:Nonlinear Structure Formation; Finder Comparison Project; Greater-Than 1, Matter Haloes, Galaxy Clusters, Angular Momentum, Quintessence Models, Massive Clusters, Shape, Spin
Subjects:Sciences > Physics
ID Code:25841
Deposited On:24 Jun 2014 16:16
Last Modified:26 Nov 2014 12:01

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