Re:The possibilities for dark matter have just shrunk – by a...
by naasking on Tuesday August 27, 2024 @11:19AM
(#41368543)
It's not clear that GR would need to be tweaked to match MOND. The GR solutions we currently use in LCDM are based on the FLRW metric, but that metric could just be the wrong fit for our universe.
Re:The possibilities for dark matter have just shrunk – by a...
by mr_mitm on Tuesday August 27, 2024 @01:13PM
(#41370071)
How is it not clear? GR reduces to Newtonian gravity in the weak field limit, which MOND is explicely not. If MOND is true, then GR is wrong.
Re:The possibilities for dark matter have just shrunk – by a...
by throwawaymaths on Tuesday August 27, 2024 @01:32PM
(#41370316)
Have some nuance. GR is already known to be "wrong" since it isn't reconcilable with QM.
If any given MOND is true, GR needs some (possibly minor) changes in the limit, just as GR needs (possibly minor) changes to accommodate QM
The thing about lensing is that we don't have a solution in (GR would need to be tweaked if MOND is true -- the math is much harder!!) so we can't really say what the lensing would look like in any given MOND-like theory yet. Seems weird to declare that MOND can't explain lensing. It's should be more qualified: "we don't think MOND can explain the lensing"