English
Related papers

Related papers: On the time dependency of $a_0$

200 papers

The weak lensing shear signal has been measured numerically in $N$-body simulations at 14 different redshifts ($z_s = 0.1$ to 3.6) and on angular scales of $\theta = 2'$ to 32'. In addition, the data have been validated by analytical…

Astrophysics · Physics 2009-11-07 Andrew J. Barber

The Planck Collaboration has shown that the number of clusters as a function of their mass and redshift is an extremely powerful tool for cosmological analyses. However, the true cluster mass is not directly measurable. Among the possible…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Antonio Ferragamo , Marco De Petris , Gustavo Yepes , Juan Macías-Pérez , Weiguang Cui , Alejandro Jiménez-Muñoz

(Abridged) Processes driving mass assembly are expected to evolve on different timescales along cosmic time. A transition might happen around z ~ 1 as the cosmic star formation rate starts its decrease. Identifying the dynamical nature of…

Whereas many measurements in cosmology depend on the use of integrated distances or time, galaxies evolving passively on a time scale much longer than their age difference allow us to determine the expansion rate H(z) solely as a function…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Jun-Jie Wei , Fulvio Melia , Xue-Feng Wu

Why does there appear in the modified dynamics (MOND) an acceleration constant, a0, of cosmological significance? An intriguing possibility is that MOND, indeed inertia itself--as embodied in the actions of free particles and fields, is due…

Astrophysics · Physics 2016-08-30 Mordehai Milgrom

McGaugh et al. (2016) have used their extensive SPARC sample to update the well-known mass-discrepancy-acceleration relation (MDAR), which is one of the major predicted "MOND laws". This is not a newly discovered relation. Rather, it…

Astrophysics of Galaxies · Physics 2016-10-10 Mordehai Milgrom

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…

Astrophysics · Physics 2010-11-11 Aleksandra Kurek , Marek Szydlowski

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…

Astrophysics · Physics 2009-11-13 Xufen Wu , HongSheng Zhao , Benoit Famaey , G. Gentile , O. Tiret , F. Combes , G. W. Angus , A. C. Robin

Keller and Wadsley (2016) have smugly suggested, recently, that the end of MOND may be in view. This is based on their claim that their highly-restricted sample of $\Lambda$CDM-simulated galaxies are "consistent" with the observed MOND…

Astrophysics of Galaxies · Physics 2016-10-25 Mordehai Milgrom

We present a new statistic-the redshift dispersion-- which may prove useful for comparing next generation redshift surveys (e.g., the Sloan Digital Sky Survey) and cosmological simulations. Our statistic is specifically designed for the…

Astrophysics · Physics 2009-10-28 Jeremy Kepner , Frank Summers , Michael Strauss

Recent attempts at measuring the variation of $c$ using an assortment of standard candles and the redshift-dependent Hubble expansion rate inferred from the currently available catalog of cosmic chronometers have tended to show that the…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-18 Fulvio Melia

We examine how the spatial correlation function of galaxies from the CNOC2 Field Galaxy Redshift Survey depends on galaxy color, luminosity and redshift. The projected correlation function w_p is determined for volume-limited samples of…

Recent puzzling observations such as the $H_o$ tension, large-scale anisotropies, and massive disk galaxies at high redshifts have been challenging the standard cosmological model. While one possible explanation is that the standard model…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-08 Lior Shamir

Lo, Sargent, and Young (1993) have recently concluded that the masses of some dwarf galaxies, as deduced by the modified dynamics (MOND) from the observed velocity dispersions, are systematically smaller than the observed masses, by a…

Astrophysics · Physics 2009-10-22 M. Milgrom

The recently proposed Skordis-Z\l{}o\'{s}nik theory is the first relativistic MOND theory that can recover the success of the standard $\Lambda$CDM model at matching observations of the cosmic microwave background. This paper aims to…

General Relativity and Quantum Cosmology · Physics 2023-03-16 Shuxun Tian , Shaoqi Hou , Shuo Cao , Zong-Hong Zhu

Dwarf and low surface brightness galaxies are ideal objects to test modified Newtonian dynamics (MOND), because in most of these galaxies the accelerations fall below the threshold below where MOND supposedly applies. We have selected from…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. A. Swaters , R. H. Sanders , S. S. McGaugh

We propose a new and highly model-independent test of cosmic acceleration by comparing observations of the baryon acoustic oscillation (BAO) scale at low and intermediate redshifts: we derive a new inequality relating BAO observables at two…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Will Sutherland

MOND predicts that the asymptotic gravitational potential of an isolated, bounded (baryonic) mass, M, is phi(r)=(MGa0)^{1/2}ln(r); a0 is the MOND constant. Relativistic MOND theories predict that the lensing effects of M are dictated by…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-26 Mordehai Milgrom

Standard cosmological models based on general relativity (GR) with dark energy predict that the Universe underwent a transition from decelerating to accelerating expansion at a moderate redshift $z_{acc} \sim 0.7$. Clearly, it is of great…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 Will Sutherland , Paul Rothnie

Milgrom's modified Newtonian dynamics (MOND) has done a great job on accounting for the rotation curves of a variety of galaxies by assuming that Newtonian dynamics breaks down for extremely low acceleration typically found in the galactic…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-01 Ling-Jun Wang