Tag

Backreaction

All articles tagged with #backreaction

science8 days ago•7 min saved

Lab Light Reveals Direct Hawking Backreaction in Black-Hole Analog

Physicists used ultrafast laser pulses in a patterned optical fiber to create a black-hole analog that emits Hawking radiation and, for the first time, observed backreaction: a tiny energy shift in the initiating pulse caused by the radiation. The study suggests a direct, biquadratic interaction mechanism, helping explain how Hawking radiation could arise in gravity, though real black holes remain unobservable. If the same mechanism appears in other analogs, it could inform the black hole information paradox.

via ScienceAlert|

#analog-experiments #backreaction #black-holes

science10 days ago•16 min saved

Direct Backreaction of Hawking-like Radiation in a Photonic Horizon

A fibre-optic analogue of a black-hole horizon demonstrates a direct, simple mechanism for generating stimulated Hawking radiation and shows its backreaction on the propagating field. By combining experiment and theory, the work provides evidence that Hawking-like quanta can arise in lab systems and that the emitted radiation can influence the original optical field, offering insights relevant to both analogue gravity experiments and real black-hole physics.

via Nature|

#analogue-gravity #backreaction #fiber-optics

science1 month ago•8 min saved

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.

via The Daily Galaxy|

#backreaction #cosmology #dyer-roeder

science2 months ago•61 min saved

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.

via Live Science|

#backreaction #cosmology #dyer-roeder