It has long been hoped that string theory will provide the answer. According to string theory, all matter consists of tiny, vibrating “stringlike” entities. The theory also requires there to be more spatial dimensions than the three that are already part of everyday knowledge. For 15 years, there have been models in string theory that have been thought to give rise to dark energy. However, these have come in for increasingly harsh criticism, and several researchers are now asserting that none of the models proposed to date are workable.
Recently, we were told that it would lead to a Theory of Everything if it were viable. You propose a new model:
In their article, the scientists propose a new model with dark energy and our Universe riding on an expanding bubble in an extra dimension. The whole Universe is accommodated on the edge of this expanding bubble. All existing matter in the Universe corresponds to the ends of strings that extend out into the extra dimension. The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes. Paper. (open access) – Souvik Banerjee, Ulf Danielsson, Giuseppe Dibitetto, Suvendu Giri, Marjorie Schillo. Emergent de Sitter Cosmology from Decaying Anti–de Sitter Space. Physical Review Letters, 2018; 121 (26) DOI: 10.1103/PhysRevLett.121.261301 More.
So this is a string theory thesis that includes our universe riding on an expanding bubble in an extra dimension. The authors hope that their work will “pave the way for methods of testing string theory.” That could come in handy, you never know.
See also: Belief in string theory is becoming, at this point, a sort of social virtue “In the real world?” So string theory is not about the real world? Even the author of the article, Mike McRae, does not sound hopeful for the theory. He compares string theory to a means of bringing warring divorced parents to talk to each other at Christmas. Virtuous, yes, but not what we usually mean by science.
PBS Video: Why String Theory Is Wrong
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?