According to the Einstein-Cartan version of gravity, there are two sources which "distort" local space-time:

1. Mass (or more generally energy-momentum tensor), which induces space-time curvature.
2. Spin current (from Dirac fermions), which induces space-time torsion.

As an alternative to missing/dark mass, we could attribute the "observed space-time geometry that does not match predictions" to dark spin current (or " flying-spaghetti-monster", if you will).

As per Poplawski, the spin current/torsion approach has another nice property that "averts the unphysical big-bang singularity, replacing it with a cusp-like bounce at a finite minimum scale factor, before which the Universe was contracting".

According to the Einstein-Cartan version of gravity, there are two sources which "distort" local space-time:

1. Mass (or more generally energy-momentum tensor), which induces space-time curvature.
2. Spin current (from Dirac fermions), which induces space-time torsion.

As an alternative to missing/dark mass, we could attribute the "observed space-time geometry that does not match predictions" to dark spin current (or dubbed as " flying-spaghetti-monster", if you will).

As per Poplawski, the spin current/torsion approach has another nice property that "averts the unphysical big-bang singularity, replacing it with a cusp-like bounce at a finite minimum scale factor, before which the Universe was contracting".