Einstein’s Cosmological (IN)Constant – Alejandro Clocchiatti

An analysis of the cosmological parameter ΩΛ fitted to subsamples of the Pantheon+ Type Ia SN
sample spanning 2𝜋 steradians for a grid of 432 pole positions covering the whole sky reveals two
large scale asymmetries. One of them is closely aligned with the rotation axis of the Galaxy and the
other points approximately 51 degrees away from the CMB dipole Apex.
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. With respect to the standard ΛCDM cosmology, SNe on the Northern Galactic
hemisphere have, on average, a distance modulus “excess” of 0.016 magnitudes while those in
the Southern Galactic hemisphere have an average excess distance modulus of only 0.010 mag.
The second asymmetry bears strong implications on our interpretation of ΩΛ 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.