Global Anisotropies of ΩΛ
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Publishing Ltd
Abstract
An analysis of the Cosmological Constant ΩΛ fitted to subsamples of the Pantheon+ Type Ia SN sample spanning 2π sterradians for a grid of 432 pole positions covering the whole sky reveals two large scale asymmetries. One of them is closely aligned with the Galactic North-South direction and the other points approximately towards RA∼ 217.5 ◦ Dec∼ −26.4 ◦ , ∼50.9 degrees from the CMB dipole Apex. The signal to noise ratio (S/N) of the multiple ΩΛ measurements in these directions is 3.2 ≲ S/N ≲ 8.4. The first asymmetry is puzzling, and would indicate a systematic effect related with the distribution of Pantheon+ SNe on the sky and, probably, how the correction for reddening in the Galaxy is calculated. The second one, which entails a 2.8-σ tension between ΩΛ measure in opposite directions, bears strong implications on its interpretation as Dark Energy: It is consistent with the prediction for tilted observers located in a Friedmann-Robertson-Walker universe who could measure an acceleration or a deceleration with a dipolar asymmetry, irrespective of what the universe as a whole is doing. In this case, ΩΛ would not be a physical entity, a real Dark Energy, but an apparent effect associated with the relativistic frame of reference transformation.
Description
Keywords
Cosmology (343), Observational Cosmology, Cosmological Constant, Supernovae