Related papers: MOND virial theorem applied to a galaxy cluster
We analyze a sample of 105 clusters having virial mass homogeneously estimated and for which galaxy magnitudes are available with a well defined high degree of completeness. In particular, we consider a subsample of 89 clusters with B_j…
We use the spherical collapse model to demonstrate that the observable average density of virialized clusters depends on the properties of dark energy along with the properties of gravity on cluster scales and can therefore be used as a…
A new class of modified gravity theories, made possible by subtle features of the canonical formulation of general covariance, naturally allows MOND-like behavior (MOdified Newtonian Dynamics) in effective space-time solutions without…
We propose a new framework unifying cold dark matter (CDM) and Modified Newtonian Dynamics (MOND) to solve their respective problems on galactic scales and large scale structure formation. In our framework the dark matter clusters on large…
The Universe on large scales is well described by the Lambda-CDM cosmological model. There however remain some heavy clouds on our global understanding, especially on galaxy scales, which we review here. While some of these clouds might…
We review recent advancements in cosmology with galaxy clusters. Galaxy clusters are the most massive objects in the Universe. Consequently the cluster number density as a function of cluster mass, or cluster abundance, is sensitive to…
Intermediate-richness galaxy groups are an important test ground for MOND. First, they constitute a distinct type of galactic systems, with their own evolution histories and underlying physical processes; secondly, they probe…
Dark matter seems to account for flat velocity curves in spiral galaxies, with further evidence for dark matter from observations of the colliding "bullet cluster" galaxies 1E0657-56. However, the baryonic Tully-Fisher relation and the mass…
To re-examine the rich cluster $\Omega$ value the CNOC Cluster Survey has observed 16 high X-ray luminosity clusters in the redshift range 0.17 to 0.55, obtaining approximately 2600 velocities in their fields. Directly adding all the K and…
We present interpretations of the line-of-sight velocity distribution of stars in the Draco dwarf spheroidal galaxy in terms of CDM and MOND assuming constant mass-to-light ratio and anisotropy. We estimate the two parameters by fitting the…
Major progresses have been made this last year towards a better knowledge of the invisible mass. Michel Spiro will talk in details about the micro-lensing experiments and their promising results; the ROSAT satellite has provided extended…
The self-binding energy and stability of a galaxy in MOND-based gravity are curiously decreasing functions of its center of mass acceleration towards neighbouring mass concentrations. A tentative indication of this breaking of the Strong…
In the past few decades, various versions of modified gravity theories were proposed to mimic the effect of dark matter. Compared with the conventional Newtonian or relativistic dynamics, these theories contain some extra apparent force…
The Lambda-CDM cosmological model is succesful at reproducing various independent sets of observations concerning the large-scale Universe. This model is however currently, and actually in principle, unable to predict the gravitational…
In this article we construct an extended relativistic f(R) theory of gravity with matter-curvature couplings F(R,L_matt) for which its weak field limit of approximation recovers the simplest version of MOND. We do this by (a) performing an…
We investigate the luminosity-temperature ($L$-$T$) relation of galaxy clusters as a probe for testing modified gravity (MG) theories, focusing on $f(R)$ gravity and symmetron models. Using an improved semi-analytic framework that…
The classical gravitational two-body problem is generalized in order to be applicable also to weak gravitational fields. The equation of motion holds both for terrestrial and large cosmic scales, the Newtonian gravitational law represents a…
Galaxy and galaxy clusters exhibit tight robust physical scaling relations between baryons and system dynamics. One such phenomenon is mass discrepancy with two leading solution spaces occupied by LCDM and MOND. Here, we propose an…
Modified Newtonian dynamics (MOND) is an empirically motivated modification of Newtonian gravity or inertia suggested by Milgrom as an alternative to cosmic dark matter. The basic idea is that at accelerations below a0 ~ 10^{-8} cm/s^2 ~…
We use the mass-to-light gradients in early-type galaxies to infer the global dark matter fraction, f_d=M_d/M_*, for these systems. We discuss implications about the total star formation efficiency in dark-matter halos and show that the…