Universe opacity and Type Ia supernova dimming

Abstract

In this paper, I revoke a debate about an origin of Type Ia supernova (SN Ia) dimming. I argue that except for a commonly accepted accelerating expansion of the Universe, a conceivable alternative for explaining this observation is universe opacity caused by light extinction by intergalactic dust, even though it is commonly assumed that this effect is negligible. Using data of the Union2.1 SN Ia compilation, I find that the standard ΛCDM model and the opaque universe model fit the SN Ia measurements at redshifts z < 1.4 comparably well. The optimum solution for the opaque universe model is characterized by the B-band intergalactic opacity λ B = 0.10 ± 0.03 Gpc −1 and the Hubble constant H 0 = 68.0 ± 2.5 km s −1 Mpc −1 . The intergalactic opacity is higher than that obtained from independent observations but still within acceptable limits. This result emphasizes that the issue of the accelerating expansion of the Universe as the origin of the SN Ia dimming is not yet definitely resolved. Obviously, the opaque universe model as an alternative to the ΛCDM model is attractive, because it avoids puzzles and controversies associated with dark energy and the accelerating expansion.

The failure of testing for cosmic opacity via the distance-duality relation

“…The opaque universe model is the flat Einstein-de Sitter model (EdS) with a non-zero opacity, being described by the Hubble constant H 0 = 67.2 km s −1 Mpc −1 , dark energy Ω Λ = 0 and the B-band opacity λ B = 0.09 mag Gpc −1 . The model parameters were obtained by fitting the SN Ia Pantheon data using the method of Vavryčuk (2019). The residua between both theoretical models and the measurements follow the normal distribution ( Fig.…”

“…The Bband opacity of the fiducial model is λ B = 0.09 mag Gpc −1 and fits the SN Ia Pantheon dataset. The fitting procedure is described in Vavryčuk (2019), where the SN Ia Union2.1 dataset was analyzed.…”

Considering light-matter interactions in Friedmann equations

“…( 22) means that the radiation pressure due to absorption acts against the gravity. The dark energy is missing in Eqs (18-20), because the Type Ia supernova dimming can successfully be explained by cosmic opacity, as discussed in Vavryčuk (2019).…”

“…Neglecting cosmic opacity produced by intergalactic dust may lead to distorting the observed evolution of the luminosity density and the global stellar mass density with redshift (Vavryčuk 2017b). Non-zero cosmic opacity may invalidate the interpretation of the Type Ia supernova (SNe Ia) dimming as a result of dark energy and the accelerating expansion of the Universe (Aguirre 1999a,b;Aguirre & Haiman 2000;Ménard et al 2010a;Vavryčuk 2019). Intergalactic dust can partly or fully produce the cosmic microwave background (CMB) (Wright 1982;Bond et al 1991;Narlikar et al 2003).…”

A non-parametric test of variability of Type Ia supernovae luminosity and CDDR

“…The cosmic acceleration rate and the cosmological parameters determined by the SNe Ia measurements are highly dependent on the possible dimming effect as well. Vavrycuk et al (2019) [36] revived a debate about an origin of Type Ia supernova (SN Ia) dimming and showed that the standard ΛCDM model and the opaque universe model (caused by light extinction by intergalactic dust) fit the SN Ia measurements at redshifts z < 1.4 fairly well. Then, there are still some possible loopholes in the current SNe Ia observations and alternative mechanisms contributing to the acceleration evidence or even mimicking the dark energy behaviour have been proposed.…”