The failures of the standard model of cosmology require a new paradigm

TL;DR

The paper discusses the limitations of the standard cosmological model and explores Modified Newtonian Dynamics (MOND) as an alternative, highlighting its successes and challenges in explaining cosmic phenomena without dark matter.

Contribution

It reviews the problems with the standard model and presents MOND as a promising alternative, emphasizing its connection to cosmological constants and the need for a relativistic theory.

Findings

MOND explains galactic mass discrepancies without dark matter.

The acceleration constant a0 relates to cosmological parameters.

Challenges remain in explaining galaxy clusters and developing a relativistic theory.

Abstract

Cosmological models that invoke warm or cold dark matter can not explain observed regularities in the properties of dwarf galaxies, their highly anisotropic spatial distributions, nor the correlation between observed mass discrepancies and acceleration. These problems with the standard model of cosmology have deep implications, in particular in combination with the observation that the data are excellently described by Modified Newtonian Dynamics (MOND). MOND is a classical dynamics theory which explains the mass discrepancies in galactic systems, and in the universe at large, without invoking dark entities. MOND introduces a new universal constant of nature with the dimensions of acceleration, a0, such that the pre-MONDian dynamics is valid for accelerations a >> a0, and the deep MONDian regime is obtained for a << a0, where space-time scale invariance is invoked. Remaining challenges for MOND are (i) explaining fully the observed mass discrepancies in galaxy clusters, and (ii) the development of a relativistic theory of MOND that will satisfactorily account for cosmology. The universal constant a0 turns out to have an intriguing connection with cosmology: \bar a0 == 2 pi a0 \approx c H_0 \approx c^2(Lambda/3)^{1/2}. This may point to a deep connection between cosmology and internal dynamics of local systems.