The road to MOND--a novel perspective

Abstract

Accepting that galactic mass discrepancies are due to modified dynamics, I show why it is specifically the MOND paradigm that is pointed to cogently. MOND is thus discussed here as a special case of a larger class of modified dynamics theories whereby galactic systems with large mass discrepancies are described by scale-invariant dynamics. This is a novel presentation that uses more recent, after-the-fact insights and data (largely predicted beforehand by MOND). Starting from a purist set of tenets, I follow the path that leads specifically to the MOND basic tenets. The main signposts are: (i) Space-time scale invariance underlies the dynamics of systems with large mass discrepancies. (ii) In these dynamics, $G$ must be replaced by a single "scale-invariant" gravitational constant, Q0 (in MOND, Q0=A0=Ga0, where a0 is MOND's acceleration constant). (iii) Universality of free fall points to the constant q0=Q0/G as the boundary between the G-controlled, standard dynamics, and the Q0-controlled, scale-invariant dynamics (in MOND, q0=a0). (iv) Data clinches the case for q0 being an acceleration (MOND).

9 pages, accepted for publication in Phys. Rev. D

References in corpus (12)

• Bimetric MOND gravity
• A Novel Test of the Modified Newtonian Dynamics with Gas Rich Galaxies
• Confrontation of MOND with the rotation curves of early-type disc galaxies
• Andromeda Dwarfs in Light of MOND. II. Testing Prior Predictions
• Andromeda Dwarfs in Light of MOND
• The high mass end of the Tully-Fisher relation
• Testing the MOND Paradigm of Modified Dynamics with Galaxy-Galaxy Gravitational Lensing
• Testing MOND Over a Wide Acceleration Range in X-Ray Ellipticals
• The Milky Way Tomography with SDSS. V. Mapping the Dark Matter Halo
• Field equations and cosmology for a class of nonlocal metric models of MOND
• Modified Newtonian Dynamics, an Introductory Review
• MOND and the dark baryons

Cited by in corpus (13)

• MOND vs. dark matter in light of historical parallels
• MOND Prediction for the Velocity Dispersion of the `Feeble Giant' Crater II
• Noncovariance at low accelerations as a route to MOND
• The global stability of M33: still a puzzle
• A fundamental test for MOND
• Radial acceleration relation and dissipative dark matter
• Interposing a Varying Gravitational Constant Between Modified Newtonian Dynamics and Weak Weyl Gravity
• Gauss's Law and the Source for Poisson's Equation in Modified Gravity with Varying G
• Quantum, noncommutative and MOND corrections to the entropic law of gravitation
• The $a_0$ -- cosmology connection in MOND
• Scale Invariance at low accelerations (aka MOND) and the dynamical anomalies in the Universe
• Mass decomposition of SLACS lens galaxies in Weyl conformal gravity
• Is MOND necessarily nonlinear?