Hacker News Reader

MOND isn't pitched as an improvement to GR. It was always a Newtonian theory - it's in its name!

There are relativistic versions of MOND, for example, TeVeS [1], but they all still have some problems.

[1] https://en.m.wikipedia.org/wiki/Tensor%E2%80%93vector%E2%80%...

TeVeS is definitely interesting, but it still has problems like you said. AFAICT gravitational wave observations are particularly bad for TeVeS theories. TeVeS isn't dead, but if dark matter theories are criticized for being patched up post-hoc, that standard should also apply to modified gravity.

The weirdest thing about TeVeS IMO is that it adds additional fields that warp spacetime, so how is it not a dark matter theory?

For the fields to be considered particles, they have to be freely propagating in space. TeVeS adds a vector field, a scalar field, and some lagrange fields that are part of their coupling. The degrees of freedom aren't consistent with one or more particles.

Reply on news.ycombinator.com