Do we reside in a shell universe?

The cosmos might not be as you think. Until recently, it seemed that the Lambda Cold Dark Matter model has a lock on cosmology. Just like earlier Big Bang models, it presumes that the universe expanded from a hyperdense state that the expansion of spacetime leads to the Hubble redshift of light. Dark energy and dark matter are added to overcome issues relating to the cosmic microwave background and the unexpected dimness of isolated supernovae.

But now, cracks have begun to appear in the model. The James Webb Space Telescope (JWST) disclosed that mature galaxies formed far too soon after the cosmos supposedly began. Other discrepancies, such as the so-called “Hubble tension” and an apparent late entrance of dark energy in the cosmos, have led to the notion that a crisis in cosmology could be imminent.

While hopes of fine-tuning the LCDM model to solve these issues remain high, new findings in general relativity point in an astoundingly different direction. In the year 2011, Jun Ni discovered a new class of solutions for the Einstein field equations of neutron stars. These solutions were completed and generalized by Jorge Lacerda de Lyra, Lubos Neslušan and others.

The Ni-Neslušan- de Lyra solutions oddly feature a shell-like configuration and a central matter void. Under the effect of a repulsive gravitational field centered on the origin, matter inside the shell cavity gets attracted towards the shell. This also causes a gravitational redshift in light traveling from the shell towards the center and a blueshift in light traveling back towards the shell. This runs contrary to the standard picture in general relativity, which features a flat, Minkowski spacetime inside a sphere-shaped shell of matter.

Every tension of the LCDM model could be resolved if the matter of the observable cosmos—in both early and late times—were concentrated in a thick Ni shell, with the Milky Way placed close to the center within the KBC Void. While this placement is at odds with the cosmological principle, inconsistencies in quasar counts and other observational “dipoles” are not inconsistent with it. In a Ni shell cosmos, the Hubble redshift seen in light from faraway stars would arise at least partially from the gravitational redshift induced by the outer shell.

The Hubble tension would then be explained with the altering derivative of ν(r), which causes the Hubble constant to progressively decrease as one moves from the center of the cosmos towards the shell. The dark energy of the LCDM model would no more be needed. Supernova dimming would instead result from the Ni redshift causing substances to appear further away from us than they actually are. The Ni approach can go much much deeper than this. With recent findings of surprisingly high mass density at high redshifts, the cosmos may have so much mass that it becomes a black hole.