Related papers: Cosmology: small scale issues
The galaxy cluster power spectrum and mass/temperature functions are currently the most precise observational tools for constraining the theory of the formation of large scale structure (LSS) in the Universe. Complementing these tests by…
Cosmological simulations of the $\Lambda$CDM model suggest that the dark matter halos of dwarf galaxies are denser in their center than what observational data of such galaxies imply. In this letter, we propose a novel solution to this…
There is increasing evidence that conventional cold dark matter (CDM) models lead to conflicts between observations and numerical simulations of dark matter halos on sub-galactic scales. Spergel and Steinhardt showed that if the CDM is…
Numerical simulation is an important tool to help us understand the process of structure formation in the universe. However many simulation results of cold dark matter (CDM) halos on small scale are inconsistent with observations: the…
The conventional cold, particle interpretation of dark matter (CDM) still lacks laboratory support and struggles with the basic properties of common dwarf galaxies, which have surprisingly uniform central masses and shallow density…
Small-scale discrepancies in the standard Lambda cold dark matter paradigm have motivated the exploration of alternative dark matter (DM) models, such as warm dark matter (WDM). We investigate the constraining power of galaxy scaling…
We discuss variants of Cold Dark Matter (CDM) dominated cosmological models that give good agreement with a range of observations. We consider models with hot dark matter, tilt, $\Omega < 1$, or a cosmological constant. We also discuss the…
The nature of dark matter is increasingly constrained by cosmological data. In this paper, we examine the implications of the Cosmic Microwave Background anisotropy limits on the density of cold dark matter under different theoretical…
Cold dark matter (CDM) constitutes most of the matter in the Universe. The interplay between dark and luminous matter in dense cosmic environments like galaxy clusters is studied theoretically using cosmological simulations. Observed…
We study clusters in Warm Dark Matter (WDM) models of a thermally produced dark matter particle $0.5$ keV in mass. We show that, despite clusters in WDM cosmologies having similar density profiles as their Cold Dark Matter (CDM)…
The concordance Cold Dark Matter model for the formation of structure in the Universe, while remarkably successful at describing observations on large scales, has a number of problems on galaxy scales. The Milky Way and its satellite system…
Numerical simulations have revealed the presence of long-lived substructure in Cold Dark Matter (CDM) halos. These surviving cores of past merger and accretion events vastly outnumber the known satellites of the Milky Way. This finding has…
Warm Dark Matter (WDM) has been invoked to resolve apparent conflicts of Cold Dark Matter (CDM) models with observations on subgalactic scales. In this work we provide a new and independent lower limit for the WDM particle mass (e.g.…
We explore an extended cosmological scenario where the dark matter is an admixture of cold and additional non-cold species. The mass and temperature of the non-cold dark matter particles are extracted from a number of cosmological…
A critical challenge to the cold dark matter (CDM) paradigm is that there are fewer satellites observed around the Milky Way than found in simulations of dark matter substructure. We show that there is a match between the observed satellite…
We speculate that the dark halos of dwarf galaxies and low surface brightness galaxies soften their central cusps by the decay of a fraction of cold dark matter (CDM) particles to a stable particle with a recoiling velocity of a few tens km…
In the thermal dark matter (DM) paradigm, primordial interactions between DM and Standard Model particles are responsible for the observed DM relic density. In Boehm et al. (2014), we showed that weak-strength interactions between DM and…
The mass and composition of dark matter (DM) particles and the shape and damping scales of the power spectrum of density perturbations can be estimated from recent observations of the DM dominated relaxed objects -- dwarf galaxies and…
In the generic CDM cosmogony, dark-matter halos emerge too lumpy and centrally concentrated to host observed galactic disks. Moreover, disks are predicted to be smaller than those observed. We argue that the resolution of these problems may…
The $\Lambda$ cold dark matter ($\Lambda$CDM) scenario well describes the Universe at large scales, but shows some serious difficulties at small scales: the inner dark matter (DM) density profiles of spiral galaxies generally appear to be…