Related papers: Machian Gravity: Confronting Galaxy Cluster Mass P…
Newtonian mechanics indicates that galaxies and galaxy clusters are much more massive than we would have guessed from their luminosities, with the discrepancy being generally attributed to dark matter halos. An alternative hypothesis is…
We test the predictions of Emergent Gravity using matter densities of relaxed, massive clusters of galaxies using observations from optical and X-ray wavebands. We improve upon previous work in this area by including the baryon mass…
Dark matter particles form halos that contribute the major part of the mass of galaxy clusters. The formation of these cosmological structures have been investigated both observationally and in numerical simulations, which have confirmed…
To further test MOdified Newtonian Dynamics (MOND) on galactic scales -- originally proposed to explain the rotation curves of disk galaxies without dark matter -- we study a sample of six strong gravitational lensing early-type galaxies…
Over the past decades, General Relativity and the concordance $\Lambda$CDM model have been successfully tested using several different astrophysical and cosmological probes based on large datasets ({\it precision cosmology}). Despite their…
Recently, the discovery of the radial acceleration relation (RAR) in galaxies has been regarded as an indirect support of alternative theories of gravity such as Modified Newtonian Dynamics (MOND) and modified gravity. This relation…
In General Relativity (GR), the graviton is massless. However, a common feature in several theoretical alternatives of GR is a non-zero mass for the graviton. These theories can be described as massive gravity theories. Despite many…
Large surveys of the local Universe have shown that galaxies with different intrinsic properties, such as colour, luminosity and morphological type display a range of clustering amplitudes. Galaxies are therefore not faithful tracers of the…
This work wants to show how standard General Relativity (GR) is able to explain galactic rotation curves without the need for dark matter, this starting from the idea that when Einstein's equations are applied to the dynamics of a galaxy…
A classical nonlocal generalization of Einstein's theory of gravitation has recently been developed via the introduction of a scalar causal "constitutive" kernel that must ultimately be determined from observational data. It turns out that…
If it is hypothesised that there is no dark matter then some alternative gravitational theory must take the place of general relativity (GR) on the largest scales. Dynamical measurements can be used to investigate the nature of such a…
In Newtonian gravity, mass is an intrinsic property of matter while in general relativity (GR), mass is a contextual property of matter, i.e., matter can simultaneously possess two different values of mass when it is responsible for two…
The common nature of dark matter and dark energy is argued in [1] based on the approach that the cosmological constant \Lambda enters the weak-field General Relativity following from Newton theorem on the "sphere-point mass" equivalency…
Galactic rotation curve is a powerful indicator of the state of the gravitational field within a galaxy. The flatness of these curves indicates the presence of dark matter in galaxies and their clusters. In this paper, we focus on the…
We study the origin of dark matter based on the ghost-free bigravity theory with twin matter fluids. The present cosmic acceleration can be explained by the existence of graviton mass, while dark matter is required in several cosmological…
Shortly after its discovery, General Relativity (GR) was applied to predict the behavior of our Universe on the largest scales, and later became the foundation of modern cosmology. Its validity has been verified on a range of scales and…
Clusters of galaxies, being dark matter dominated, have long been and still are the ideal cosmological targets to study the nature of dark matter. Constraints on the nature of dark matter comes in particular from the observational…
We use gas dynamic simulations to explore the effects of galactic winds on galaxy clusters. Two ensembles of 18 realizations, spanning a decade in temperature, are evolved with and without winds in an underlying biased CDM cosmology.…
We use the Cluster-EAGLE simulations to explore the velocity bias introduced when using galaxies, rather than dark matter particles, to estimate the velocity dispersion of a galaxy cluster, a property known to be tightly correlated with…
Einstein gravity coupled to a massive skew symmetric field F_{\mu\nu\lambda} leads to an acceleration law that modifies the Newtonian law of attraction between particles. We use a framework of non-perturbative renormalization group…