Modified Einstein's gravity as a possible missing link between sub- and super-Chandrasekhar type Ia supernovae

TL;DR

This paper investigates how modifications to Einstein's gravity can alter white dwarf masses, potentially explaining the diversity in Type Ia supernova luminosities and suggesting that the Chandrasekhar limit and Einstein's gravity might not be universal.

Contribution

It introduces a model where modified gravity causes white dwarfs to have sub- and super-Chandrasekhar masses, unifying different supernova types and challenging existing theories.

Findings

Modified gravity leads to white dwarf masses below and above the Chandrasekhar limit.

Explains under- and over-luminous Type Ia supernovae as resulting from these mass variations.

Proposes that Einstein's gravity and the Chandrasekhar limit are not universally applicable.

Abstract

We explore the effect of modification to Einstein's gravity in white dwarfs for the first time in the literature, to the best of our knowledge. This leads to significantly sub- and super-Chandrasekhar limiting masses of white dwarfs, determined by a single model parameter. On the other hand, type Ia supernovae (SNeIa), a key to unravel the evolutionary history of the universe, are believed to be triggered in white dwarfs having mass close to the Chandrasekhar limit. However, observations of several peculiar, under- and over-luminous SNeIa argue for exploding masses widely different from this limit. We argue that explosions of the modified gravity induced sub- and super-Chandrasekhar limiting mass white dwarfs result in under- and over-luminous SNeIa respectively, thus unifying these two apparently disjoint sub-classes and, hence, serving as a missing link. Our discovery raises two fundamental questions. Is the Chandrasekhar limit unique? Is Einstein's gravity the ultimate theory for understanding astronomical phenomena? Both the answers appear to be no.