> We test a class of holographic models for the very early universe against cosmological observations and find that they are competitive to the standard ΛCDM model of cosmology. These models are based on three dimensional perturbative super-renormalizable Quantum Field Theory (QFT), and while they predict a different power spectrum from the standard power-law used in ΛCDM, they still provide an excellent fit to data (within their regime of validity). By comparing the Bayesian evidence for the models, we find that ΛCDM does a better job globally, while the holographic models provide a (marginally) better fit to data without very low multipoles (i.e. l≲30), where the dual QFT becomes non-perturbative. Observations can be used to exclude some QFT models, while we also find models satisfying all phenomenological constraints: the data rules out the dual theory being Yang-Mills theory coupled to fermions only, but allows for Yang-Mills theory coupled to non-minimal scalars with quartic interactions. Lattice simulations of 3d QFT's can provide non-perturbative predictions for large-angle statistics of the cosmic microwave background, and potentially explain its apparent anomalies.
The evidence appears to be "this is almost as good as state-of-the-art normal cosmic inflation theory." Which is to say, it's more of a lack of proof against than strong evidence for--it's not providing explanations for unexplained observances.
Hmm, this actually makes me much more excited. I finished with grappling existential issues about being a simulation a long time ago; I don't see the point anymore. But if I understand this right, this would give us reason to believe we could simulate absolutely tiny models of the universe with relatively high (still quite low) confidence it's meaningful. Is that fair?
Your summary was almost exactly what I was going to write, based on the abstract.
That said, though, a not-quite-as-good match after a very few years' work is kind of promising. After as long as the standard model has been worked on, the match might be as good.
> We test a class of holographic models for the very early universe against cosmological observations and find that they are competitive to the standard ΛCDM model of cosmology. These models are based on three dimensional perturbative super-renormalizable Quantum Field Theory (QFT), and while they predict a different power spectrum from the standard power-law used in ΛCDM, they still provide an excellent fit to data (within their regime of validity). By comparing the Bayesian evidence for the models, we find that ΛCDM does a better job globally, while the holographic models provide a (marginally) better fit to data without very low multipoles (i.e. l≲30), where the dual QFT becomes non-perturbative. Observations can be used to exclude some QFT models, while we also find models satisfying all phenomenological constraints: the data rules out the dual theory being Yang-Mills theory coupled to fermions only, but allows for Yang-Mills theory coupled to non-minimal scalars with quartic interactions. Lattice simulations of 3d QFT's can provide non-perturbative predictions for large-angle statistics of the cosmic microwave background, and potentially explain its apparent anomalies.
The evidence appears to be "this is almost as good as state-of-the-art normal cosmic inflation theory." Which is to say, it's more of a lack of proof against than strong evidence for--it's not providing explanations for unexplained observances.