An astrophysicist suggests:
Even though we don’t know what dark energy is, over the years theorists have made some feeble attempts to potentially explain it (because, obviously, it must have some physical source, and explaining physical sources of things we see in nature is the job of theorists). One of the most attractive ideas floating around out there is that there is some sort of quantum field that is responsible for dark energy and keeping the pedal to the cosmological metal. Quantum fields are pretty handy — they soak every bit of space-time and are responsible for generating the forces and particles that make up our everyday existence — and so it’s not so crazy to imagine that there’s a new quantum field (one never before known to science) that has just the right properties to trigger accelerated expansion…
By allowing for multiple quantum fields to generate dark energy, it might be possible for string theory to still be relevant in our universe, as these models may not be stuck in the “swampland.”
But that means we have to find evidence that there is more than one agent responsible for dark energy.Paul Sutter, “Is there more than one dark energy?” at Space.com
It sounds as though they’ll be at this a long time. We’ve never found any dark matter, let alone dark energy.
See also: Rob Sheldon: Are “multiple measurements ”closing in on dark energy? Nope.
Researchers: Either dark energy or string theory is wrong. Or both are. But dark energy is so glitzy! Isn’t it a line of cosmetics already?
Researchers: The symmetrons needed to explain dark energy were not found
Rob Sheldon: Has dark energy finally been found? In pop science mags?
Are recent dark energy findings a blow for multiverse theory?
Science at sunset: Dark energy might make a multiverse hospitable to life… if it exists