Related papers: Rings and shells of "dark matter" as MOND artifact…
(abridged) The Milky Way (MW) and Andromeda (M31) galaxies possess rotating planes of satellites. Their formation has not been explained satisfactorily yet. It was suggested that the MW and M31 satellites are ancient tidal dwarf galaxies,…
It was recently proposed that the effects usually attributed to particle dark matter on galaxy scales are due to the displacement of dark energy by baryonic matter, a paradigm known as emergent gravity. This formalism leads to predictions…
I pinpoint a previously unrecognized MOND effect that may act in the inner solar system, and is due to the galactic acceleration, g_g=eta*a0: a byproduct of the MOND external-field effect. Predictions of the effect are not generic to the…
Context. Many ellipticals are surrounded by round stellar shells probably stemming from minor mergers. A new method for constraining gravitational potential in elliptical galaxies has recently been suggested. It uses the spectral line…
We model the collapse of a spherically symmetric, constant density, pressureless shell onto a preexisting black hole. Contrary to a recent claim of Liu and Zhang (2009), we show that an observer at infinity never sees any part of the shell…
Dark matter is hypothetical matter believed to address the missing mass problem in galaxies. However, alternative theories, such as Modified Newtonian Dynamics (MOND), have been notably successful in explaining the missing mass problem in…
In this talk I summarize a novel framework that unifies the stunning success of MOND on galactic scales with the triumph of the $\Lambda$CDM model on cosmological scales. This is achieved through the rich and well-studied physics of…
Stellar occultations provide a powerful tool to explore objects of the outer solar system. The Gaia mission now provides milli-arcsec accuracy on the predictions of these events and makes possible observations that were previously…
The presence of dark matter, though well established by indirect evidence, is yet to be observed directly. Various dark matter detection experiments running for several years have yielded no positive results. In view of these negative…
It is shown that the foundational axioms of MOND alone predict a strong correlation between a bulk measure of the baryonic surface density, $\Sigma_B$, and the corresponding dynamical one, $\Sigma_D$, of an isolated object, such as a…
We present a weak lensing mass reconstruction of the interacting cluster 1E0657-558 in which we detect both the main cluster and a sub-cluster. The sub-cluster is identified as a smaller cluster which has just undergone initial in-fall and…
The presence of unseen halos of ``dark matter'' has long been inferred from the high rotation speeds of gas and stars in the outer parts of spiral galaxies$^{1}$. The volume density of this dark matter decreases less quickly from the…
We examine the properties of dark matter halos within a rich galaxy cluster using a high resolution simulation that captures the cosmological context of a cold dark matter universe. The mass and force resolution permit the resolution of 150…
In this paper we review the main and the most recent evidence for the presence of a core radius in the distribution of the dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an…
Galaxy cluster mass distributions are useful probes of Omega_0 and the nature of the dark matter. Large clusters will distort the observed shapes of background galaxies through gravitational lensing allowing the measurement of the cluster…
Galaxy groups, which have hardly been looked at in MOND, afford probing the acceleration discrepancies in regions of system-parameter space that are not accessible in well-studied galactic systems, such as galaxies, galaxy clusters, and…
We study weak gravitational lensing of galaxy clusters in terms of the MOND (MOdified Newtonian Dynamics) theory. We calculate shears and convergences of background galaxies for three clusters (A1689, CL0024+1654, CL1358+6245) and the mean…
A generic feature of nearly out-of-equilibrium dissipative systems is that they resonate through a set of quasinormal modes. Black holes - the absorbing objects par excellence - are no exception. When formed in a merger, black holes vibrate…
In recent years, the evidence for the existence of an ultra-compact concentration of dark mass associated with the radio source Sgr A* in the Galactic Center has become very strong. However, an unambiguous proof that this object is indeed a…
I investigate the caustics produced by the fall of collisionless dark matter in and out of a galaxy in the limit of negligible velocity dispersion. The outer caustics are spherical shells enveloping the galaxy. The inner caustics are rings.…