Abstract
No more salient issue exists in contemporary astrophysics and cosmology than
that of the elusive "dark matter". For many years already Milgrom's paradigm of
modified Newtonian dynamics (MOND) has provided an alternative way to interpret
observations without appeal to invisible dark matter. MOND had been successful
in elucidating economically the dynamics of disk galaxies of all scales, while
doing less well for clusters of galaxies; in its original form it could not
address gravitational lensing or cosmology. After reviewing some of the
evidence in favor of MOND, I recollect the development of relativistic
formulations for it to cope with the last deficiency. I comment on recent work
by various groups in confronting TeVeS, a relativistic embodiment of MOND, with
observational data on gravitational lensing and cosmology. Throughout I ask
what sort of physics can be responsible for the efficacy of MOND, and conclude
with an appraisal of what theoretical developments are still needed to reach a
full description of the world involving no unobserved matter.
Users
Please
log in to take part in the discussion (add own reviews or comments).