Testing the cosmic conservation of photon number with type Ia supernovae and ages of old objects

TL;DR

This study tests the conservation of photon number over cosmic history by comparing galaxy ages and supernova distances, finding no significant deviation from photon conservation within current observational uncertainties.

Contribution

It introduces a novel method using galaxy ages independent of luminosity to test photon conservation across redshifts, providing constraints on possible photon number violations.

Findings

No significant deviation from photon conservation detected.

Constraints on photon number violation parameter psilon consistent with zero.

Estimated incubation time of old objects aligns with cosmological models.

Abstract

In this paper, we obtain luminosity distances by using ages of 32 old passive galaxies distributed over the redshift interval $0.11 < z < 1.84$ and test the cosmic conservation of photon number by comparing them with 580 distance moduli of type Ia supernovae (SNe Ia) from the so-called Union 2.1 compilation. Our analyses are based on the fact that the method of obtaining ages of galaxies relies on the detailed shape of galaxy spectra but not on galaxy luminosity. Possible departures from cosmic conservation of photon number is parametrized by $\tau(z) = 2 \epsilon z$ and $\tau(z) = \epsilon z/(1+z)$ (for $\epsilon =0$ the conservation of photon number is recovered). We find $\epsilon=0.016^{+0.078}_{-0.075}$ from the first parametrization and $\epsilon=-0.18^{+0.25}_{-0.24}$ from the second parametrization, both limits at 95\% c.l. In this way, no significant departure from cosmic conservation of photon number is verified. In addition, by considering the total age as inferred from Planck (2015) analysis, we find the incubation time $t_{inc}=1.66\pm0.29$ Gyr and $t_{inc}=1.23\pm0.27$ Gyr at 68\% c.l. for each parametrization, respectively.}