宇宙定数問題では、観測されているダークエネルギーは予想されている量を圧倒的に下回る

とりあえず問題の辻褄を合わせるために一時的に作られたのがマルチバース理論なわけだが
何しろ観測できないエーテルにすべて説明を投げているのだから当然だ

https://en.wikipedia.org/wiki/Cosmological_constant_problem
In cosmology, the cosmological constant problem or vacuum catastrophe is the disagreement between the
observed values of vacuum energy density (the small value of the cosmological constant) and theoretical
large value of zero-point energy suggested by quantum field theory.

Depending on the Planck energy cutoff and other factors, the discrepancy is as high as 120 orders of magnitude,
[1] a state of affairs described by physicists as "the largest discrepancy between theory and experiment in all of
science"[1] and "the worst theoretical prediction in the history of physics."[2]