Probing modified gravity in cosmic filaments [CEA]

http://arxiv.org/abs/1807.07287


Multiple modifications of general relativity (GR) have been proposed in the literature in order to understand the nature of the accelerated expansion of the Universe. However, thus far all the predictions of GR have been confirmed with constantly increasing accuracy. In this work, we study the imprints of a particular class of models — `screened’ modified gravity theories — on cosmic filaments. We utilize the $N$-body code ISIS/RAMSES to simulate the symmetron model and the Hu-Sawicky $f(R)$ model, and we post-process the output with DisPerSE to identify the filaments of the cosmic web. We investigate how the global properties of the filaments — such as their lengths, masses, and thicknesses — as well as their radial density and speed profiles change under different gravity theories. We find that filaments are, on average, shorter and denser in modified gravity models compared to in $\Lambda$CDM. We also find that the speed profiles of the filaments are enhanced, consistent with theoretical expectations. Overall, our results suggest that cosmic filaments can be an effective complementary probe of screened modified gravity theories on Mpc scales.

Read this paper on arXiv…

A. Ho, M. Gronke, B. Falck, et. al.
Fri, 20 Jul 18
13/63

Comments: 11 pages, 17 figures, submitted to A&A