Related papers: The Possible Equation Of State Of Dark Matter in L…
We present high-resolution rotation curves of a sample of 26 low surface brightness galaxies. From these curves we derive mass distributions using a variety of assumptions for the stellar mass-to-light ratio. We show that the predictions of…
The `core-cusp' problem is considered a key challenge to the LCDM paradigm. Halos in dark matter only simulations exhibit `cuspy' profiles, where density continuously increases towards the centre. However, the dark matter profiles of many…
We investigate the properties of the baryonic and the dark matter components in low surface brightness (LSB) disc galaxies, with central surface brightness in the B band $\mu_0 \geq 23 \, mag \, arcsec^{-2}$. The sample is composed by 72…
We investigate whether a correlation exists between the concentration and spin parameters of dark matter haloes forming in LCDM N-body simulations. In particular, we focus on haloes with virial masses characteristic of the hosts of Low…
The presence of a dark matter core in the central kiloparsec of many dwarf galaxies has been a long standing problem in galaxy formation theories based on the standard cold dark matter paradigm. Recent cosmological simulations, based on…
Self-interacting dark matter has been proposed as a hypothesis to explain the shallow central slopes of the density profiles of dark matter halos in galaxies. In order to be consistent with observational studies at scales of galaxy…
One of the predictions of the standard CDM is that dark haloes have centrally divergent density profiles. An extensive body of rotation curve observations of dwarf and low surface brightness galaxies shows the dark haloes of those systems…
The standard cold dark matter (CDM) model has recently been challenged by the claim that dwarf galaxies have dark matter halos with constant density cores. Consequently, numerous alternative dark matter candidates have recently been…
We performed a series of high-resolution $N$-body simulations to examine whether dark matter candidates in the form of primordial black holes (PBHs) can solve the cusp-core problem in low-mass dwarf galaxies. If some fraction of the dark…
N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…
Low surface brightness galaxies are an excellent laboratory where stars and baryonic matter act as tracers of the gravitational potential of the dark matter halo. If dark matter is modeled as a perfect fluid, then spherically symmetric and…
The cold dark matter model of structure formation faces apparent problems on galactic scales. Several threads point to excessive halo concentration, including central densities that rise too steeply with decreasing radius. Yet, random…
The rotation velocity profiles of galaxies (rotation curves) remain unexpectedly flat at large distances, where visible matter alone should make the rotation velocity decrease with radius. Conventionally, this requires a large amount of…
Self-consistent bars that form in galaxies embedded within cuspy halos are unable to flatten the cusp. Short bars form in models with quasi-flat rotation curves. They lose angular momentum to the halo through dynamical friction, but the…
In the present paper, we improve the "Extended Secondary Infall Model" (ESIM) of Williams et al. (2004) to obtain further insights on the cusp/core problem. The model takes into account the effect of ordered and random angular momentum,…
We combine observed properties of galaxies as the core density and radius with the theoretical linear evolution of density fluctuations computed from first principles since the end of inflation till today. The halo radius r_0 is computed in…
Dark matter-only simulations predict that dark matter halos have steep, cuspy inner density profiles, while observations of dwarf galaxies find a range of inner slopes that are often much shallower. There is debate whether this discrepancy…
We analyze the observed properties of dwarf galaxies, which are dark matter dominated astrophysical objects, by assuming that dark matter is in the form of a strongly - coupled, dilute Bose - Einstein condensate. The basic astrophysical…
The standard cosmological model, now strongly constrained by direct observation at early epochs, is very successful in describing the structure of the evolved universe on large and intermediate scales. Unfortunately, serious contradictions…
We report on SPT-CLJ2011-5228, a giant system of arcs created by a cluster at $z=1.06$. The arc system is notable for the presence of a bright central image. The source is a Lyman Break galaxy at $z_s=2.39$ and the mass enclosed within the…