Physical origin of temporal singularities

Determine the physical origin and generating mechanism of the proposed temporal singularities—delta-function events in cosmic mass-energy density and pressure that occur at discrete expansion factors a=η, with profiles ρ(a)=ξ(η) a^3 δ(a−η) and p(a)=−3 ξ(η) a^2 δ′(a−η)—so that they satisfy general-relativistic mass-energy conservation and the strong energy condition while reproducing the observed expansion history without requiring omnipresent dark matter or dark energy.

Background

The paper introduces a model in which dark matter and dark energy are replaced by temporally intermittent singularities of the cosmic fluid’s density and pressure. These singularities are modeled as delta-function spikes in time that, when temporally unresolved, collectively mimic the observed expansion history, including epochs of deceleration and acceleration, while satisfying the continuity equation and energy conditions.

While the mathematical construction is presented, the author explicitly notes that the physical origin of these temporal singularities is not known, drawing an analogy to the unknown origin of the Big Bang’s initial singularity.