2026/07/10 by D. Szalkai · 1 voice
paper · doi:10.5281/zenodo.21298817
openalex publication_date 2026/07/10 · openalex created_date 2026/07/12 · openalex updated_date 2026/07/17
Perfect-fluid cosmology is a highly successful background closure, but it removes dissipative transport channels before the full kinematic structure of the Raychaudhuri equation is compared with the material source. This note asks whether part of the effective residual source usually represented by dark-sector terms may instead arise from a delayed, non-perfect source closure. We present a channel-by-channel comparison between the Raychaudhuri equation and a dissipative relativistic fluid source, retaining the bulk, shear, vorticity, acceleration and flux channels until the relevant projections are performed. Within a representative weak-field scalar closure, the bulk channel gives a density-scale negative pressure contribution, while the shear and vorticity sectors yield non-trivial matching coefficients. This suggests a possible cosmological reading in which effective dust, dark-matter-like clustered response, and Λ-like pressure are not introduced as separate assumptions, but arise as different regimes of the same non-perfect closure. The construction is intended as a structural compatibility test between standard geometric and dissipative source channels, and as motivation for backreaction-sensitive cosmological modelling. Presentation can be found here: https://site.pheedloop.com/event/lrb26/schedule