Dark Energy

[surreptitious57]

What is the most popular hypothesis for what dark energy is

[Mordred]

At one time, quantum process via virtual particle/ antiparticle pair production. This process was later shown unlikely due to too much energy in the process. About the same time quintessence, which didn't match.

 

Now I would say a possibility involves the Higgs field. At least the majority of recent papers are moving in that direction.