Nobody has unified field theories yet but could dark energy if considered as a field be useful in this endeavour?

  • $\begingroup$ Something like "quintessence"? $\endgroup$ Mar 18 '21 at 14:05
  • $\begingroup$ If there is no unified field theory, and nobody knows what dark energy is, it is pretty difficult to tell what "could" be. Could it be considered by Maxwell, that the speed of light is the same in any inertial frame? Could Newton have envisioned that gravitation spreads like a wave? Could have Rutherford imagined that there is not only an atomic nucleus but that it is composed of neutrons and protons, each of which is composed of three quarks that are inseparable from one another? $\endgroup$
    – oliver
    Mar 18 '21 at 14:54

Probably everyone who has ever attempted some progress in grand unified field theory has also considered the issue of dark energy and whether their work has any bearing on it. If indeed there is a non-zero cosmological-constant-like term in the Einstein field equation, as cosmological evidence suggests (but does not establish beyond all reasonable doubt), then a natural way to suggest how it comes about is by appealing to the nature of the vacuum presented by almost any quantum field theory. The problem is that if one does this in any of the most straightforward ways, then one gets either a prediction too large by many orders of magnitude, or else the prediction zero. It is hard to get anything in between.

As things stand at the moment dark energy is not yet offering any useful data to attempts at generalized field theories, as far as I know. But, as I say, it is natural for anyone working in theoretical physics to be aware of the issue and see if they can make any use of it, or offer anything towards better understanding.