Effects of Coupled Dark Energy on the Milky Way and its Satellites

Abstract

We present the first numerical simulations in coupled dark energy cosmologies with high enough resolution to investigate the effects of the coupling on galactic and sub-galactic scales. We choose two constant couplings and a time-varying coupling function and we run simulations of three Milky-Way-size halos ($\sim$10${}^{12}$M${}_{\odot }$), a lower mass halo (6$\times$10${}^{11}$M${}_{\odot }$) and a dwarf galaxy halo (5$\times$10${}^9$M${}_{\odot }$). We resolve each halo with several millions dark matter particles. On all scales the coupling causes lower halo concentrations and a reduced number of substructures with respect to LCDM. We show that the reduced concentrations are not due to different formation times, but they are related to the extra terms that appear in the equations describing the gravitational dynamics. On the scale of the Milky Way satellites, we show that the lower concentrations can help in reconciling observed and simulated rotation curves, but the coupling values necessary to have a significant difference from LCDM are outside the current observational constraints. On the other hand, if other modifications to the standard model allowing a higher coupling (e.g. massive neutrinos) are considered, coupled dark energy can become an interesting scenario to alleviate the small-scale issues of the LCDM model.

12 pages, 16 figures, submitted to MNRAS

References in corpus (9)

• Cosmology and the Fate of Dilatation Symmetry
• The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• Forged in FIRE: cusps, cores, and baryons in low-mass dwarf galaxies
• Dark matter subhalos and the dwarf satellites of the Milky Way
• Do WMAP data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?
• Strongly Coupled Dark Energy Cosmologies: preserving LCDM success and easing low scale problems II - Cosmological simulations
• Strongly Coupled Dark Energy Cosmologies: preserving LCDM success and easing low scale problems I - Linear theory revisited

Cited by in corpus (11)

• Interacting dark energy in the early 2020s: a promising solution to the $H_0$ and cosmic shear tensions
• Remedy of some cosmological tensions via effective phantom-like behavior of interacting vacuum energy
• Cosmological direct detection of dark energy: non-linear structure formation signatures of dark energy scattering with visible matter
• Constraining the mass of the Local Group
• Constraining interacting dark energy models with the halo concentration-mass relation
• Simulation techniques for modified gravity
• The impact of dark energy on galaxy formation. What does the future of our Universe hold?
• Estimation of the masses in the Local Group by Gradient Boosted Decision Trees
• On the Mass Assembly History of the Local Group
• The CIDER simulations: Nonlinear structure formation in the Constrained Interacting Dark Energy Scenario
• Dynamics of expansion of the Universe in the models with non-minimally coupled dark energy