Non-comoving Cold Dark Matter in a $\Lambda$CDM background

Abstract

We examine the evolution of peculiar velocities of cold dark matter (CDM) in localized arrays of inhomogeneous cosmic structures in a $\Lambda$CDM background that can be identified as a frame comoving with the Cosmic Microwave (CMB). These arrays are constructed by smoothly matching to this cosmological background regions of Szekeres-II models whose source is an imperfect fluid reinterpreted as non-comoving dust, keeping only first order terms in $v/c$. Considering a single Szekeres-II region matched along two comoving interfaces to a $\Lambda$CDM background, the magnitudes of peculiar velocities within this region are compatible with values reported in the literature, while the present day Hubble expansion scalar differs from that of the $\Lambda$CDM background value by a 10\% factor, a result that might provide useful information to the ongoing debate on the $H_0$ tension. While the models cannot describe the virialization process, we show through a representative example that structures of galactic cluster mass reach the onset of this process at redshifts around $z\sim 3$.

arXiv comment15 pages, 8 figures

References in corpus (21)

• The density and peculiar velocity fields of nearby galaxies
• Effects of Baryons and Dissipation on the Matter Power Spectrum
• A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications
• Geometry of General Hypersurfaces in Spacetime: Junction Conditions
• Cosmological simulations of galaxy clusters
• Cosmic microwave background anisotropies: Nonlinear dynamics
• Cosmic spherical void via coarse-graining and averaging non-spherical structures
• Differential cosmic expansion and the Hubble flow anisotropy
• Quasi-Newtonian dust cosmologies
• The growth of structure in the Szekeres inhomogeneous cosmological models and the matter-dominated era
• Multiple non-spherical structures from the extrema of Szekeres scalars
• General relativistic analysis of peculiar velocities
• Large-scale growth evolution in the Szekeres inhomogeneous cosmological models with comparison to growth data
• Coarse-grained description of cosmic structure from Szekeres models
• Non-Spherical Szekeres models in the language of Cosmological Perturbations
• Szekeres Universes with Homogeneous Scalar Fields
• Relativistic approach to the kinematics of large-scale peculiar motions
• The effects of peculiar velocities in SN Ia environments on the local $H_0$ measurement
• Lagrangian theory of structure formation in relativistic cosmology. VI. Comparison with Szekeres exact solutions
• Pancakes as opposed to Swiss Cheese
• Non-comoving baryons and cold dark matter in cosmic voids

Cited by in corpus (7)

• Exploring non-cold dark matter in a scenario of dynamical dark energy with DESI DR2 data
• The deceleration parameter in `tilted' universes: generalising the Friedmann background
• Peculiar velocities in the early universe
• Imprints of decaying dark matter on cosmic voids
• Revisiting the phenomenologically emergent dark energy model: is non-zero equation of state of dark matter favored by DESI DR2?
• Big Bang in Dipole Cosmology
• When Dark Matter Heats Up: A Model-Independent Search for Non-Cold Behavior