相关论文: How Zwicky already ruled out modified gravity theo…

The physical processes defining the dynamics of disk galaxies are still poorly understood. Hundreds of articles have appeared in the literature over the last decades without arriving at an understanding within a consistent gravitational…

Galaxies are the basic structural element of the universe; galaxy formation theory seeks to explain how these structures came to be. I trace some of the foundational ideas in galaxy formation, with emphasis on the need for non-baryonic cold…

Since the 1930s, astronomical observations have accumulated evidence that our understanding of the dynamics of galaxies and groups of galaxies is grossly incomplete: assuming the validity of Newton's law of gravity on astronomical scales,…

We consider for the first time the implications on the modified gravity MOND model of galaxies, of the presence of dark baryons, under the form of cold molecular gas in galaxy discs. We show that MOND models of rotation curves are still…

In 1929 Zwicky proposed a tired light theory to interpret the Hubble law (Hubble 1929). The key of the tired light theory is to interpret the observed redshift of galaxy as the non-Doppler effect. But the derivation of the dark matter in…

The current standard model of cosmology assumes that the majority of matter in the Universe is made of dark matter, and that the latter is fundamentally different from ordinary matter. Dark matter can in principle explain the rotation of…

We continue our study of the application of the conformal gravity theory to galactic rotation curves. Previously we had studied a varied 111 spiral galaxy sample consisting of high surface brightness galaxies, low surface brightness…

We show that treating gravitation as a thermodynamical theory leads to the modified Newton dynamics (MOND) equations if one takes into account the Hubble's expansion. Then the universal MOND acceleration a0 is exactly twice the product of…

An impact model of gravity designed to emulate Newton's law of gravitation is applied to the radial acceleration of disk galaxies. Based on this model (Wilhelm et al. 2013), the rotation velocity curves can be understood without the need to…

In this thesis, we investigate some aspects of dark matter phenomenology and its predictive power in explaining the flattening of galaxy rotation curves at large distances. After outlining the Standard Model of particle physics, its…

Observations show that about the 20% of the Universe is composed by invisible (dark) matter (DM), for which many candidates have been proposed. In particular, the anomalous behavior of rotational curves of galaxies (i.e. the flattening at…

More than sixty years ago Zwicky made the case that the great clusters of galaxies are held together by the gravitational force of unseen (dark) matter. Today, the case is stronger and more precise: Dark, nonbaryonic matter accounts for 30%…

Large values for the mass-to-light ratio (") in self-gravitating systems is one of the most important evidences of dark matter. We propose a expression for the mass-to-light ratio in spherical systems using MOND. Results for the COMA…

The non-gauge vector field with as simple as possible Lagrangian (\ref{Lagrangian}) turned out an adequate tool for macroscopic description of the main properties of dark matter. The dependence of the velocity of a star on the radius of the…

Modified Newtonian Dynamics (MOND) is a framework of theories that adjust Newton's laws of gravity to explain effects such as galactic rotation anomalies, offering an alternative to dark matter. This essay examines the justification of MOND…

We highlight phenomenological aspects of Verlinde's recent proposal to account for the mass anomalies in galactic systems without dark matter -- in particular in their relation to MOND. Welcome addition to the MOND lore as it is, this…

Numerous astrophysical observations have shown that classical Newtonian dynamics fails on galactic scales and beyond, if only visible matter is taken into account. The two most popular theoretical concepts dealing with this problem are Dark…

The existence of "dark matter", inferred from the observed rotation curves of galaxies, is a hypothesis which is widely regarded as problematic. This paper proposes an alternative hypothesis based on the space-time geometry near a rotating…

We study the cosmology of general massive gravity theories with five propagating degrees of freedom. This large class of theories includes both the case with a residual Lorentz invariance as the cases with simpler rotational invariance. We…

Galaxy velocities in clusters, rotation curves of galaxies, and "vertical" oscillations in the Milky Way currently show too high velocities with respect to the masses thought to be involved. While these velocity excesses are currently…