Tag

Dyer Roeder

All articles tagged with #dyer roeder

Cosmic Web May Rewrite Cosmology's Foundational Assumptions
science12 days ago

Cosmic Web May Rewrite Cosmology's Foundational Assumptions

New cosmological analyses using supernovae, galaxy surveys, and machine-learning reconstructions reveal small but persistent deviations from the standard FLRW description of a uniform, isotropic universe. If confirmed, these effects—potentially driven by Dyer-Roeder light propagation and cosmic backreaction from large-scale structures—could challenge the Lambda-CDM framework and require new physics or revisions of how space-time evolves, with future DESI, Euclid, and other surveys poised to test the results.

Cosmology on the Brink: Subtle Clues That the Universe Isn’t Uniform
science13 days ago

Cosmology on the Brink: Subtle Clues That the Universe Isn’t Uniform

Physicists tested a cornerstone of modern cosmology — that the universe is uniform on large scales (FLRW cosmology) — using new diagnostic tests and data from Pantheon+ supernovae, DESI, and baryon acoustic oscillations. They found mild but intriguing deviations (about 2–4 sigma) from standard FLRW predictions, which could point to light propagating through underdense regions (Dyer–Roeder effect) or to the impact of cosmic structure growth (backreaction). The results are preliminary and highly dataset-dependent, so more precise observations are needed to confirm whether the standard cosmological model needs updating.