Cluster abundance in chameleon f(R) gravity I: toward an accurate halo mass function prediction

Cataneo, Matteo; Rapetti, David; Lombriser, Lucas; Li, Baojiu

Abstract

We refine the mass and environment dependent spherical collapse model of chameleon f(R) gravity by calibrating a phenomenological correction inspired by the parameterized post-Friedmann framework against high-resolution N-body simulations. We employ our method to predict the corresponding modified halo mass function, and provide fitting formulas to calculate the enhancement of the f(R) halo abundance with respect to that of General Relativity (GR) within a precision of lesssim 5% from the results obtained in the simulations. Similar accuracy can be achieved for the full f(R) mass function on the condition that the modeling of the reference GR abundance of halos is accurate at the percent level. We use our fits to forecast constraints on the additional scalar degree of freedom of the theory, finding that upper bounds competitive with current Solar System tests are within reach of cluster number count analyses from ongoing and upcoming surveys at much larger scales. Importantly, the flexibility of our method allows also for this to be applied to other scalar-tensor theories characterized by a mass and environment dependent spherical collapse.

Citation

Cataneo, M., Rapetti, D., Lombriser, L., & Li, B. (2016). Cluster abundance in chameleon f(R) gravity I: toward an accurate halo mass function prediction. Journal of Cosmology and Astroparticle Physics, 2016(12), Article 024. https://doi.org/10.1088/1475-7516/2016/12/024

• Journal Article Type: Article
• Acceptance Date: Dec 5, 2016
• Online Publication Date: Dec 13, 2016
• Publication Date: Dec 13, 2016
• Deposit Date: Aug 21, 2016
• Publicly Available Date: Dec 13, 2017
• Journal: Journal of Cosmology and Astroparticle Physics
• Electronic ISSN: 1475-7516
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 2016
• Issue: 12
• Article Number: 024
• DOI: https://doi.org/10.1088/1475-7516/2016/12/024
• Public URL: https://durham-repository.worktribe.com/output/1377565
• Related Public URLs: http://arxiv.org/abs/1607.08788