In a study recently published in the journal General Relativity and Gravitation, Neves suggests the elimination of a key aspect of the standard cosmological model: The need for a spacetime singularity known as the Big Bang.
“I believe the Big Bang never happened,” the physicist said, who works as a researcher at the University of Campinas’s Mathematics, Statistics & Scientific Computation Institute in Sao Paulo State, Brazil.
“In order to measure the rate at which the universe is expanding with the standard cosmology in which there’s a Big Bang, a mathematical function is used that depends only on cosmological time,” said Neves, who elaborated the idea with Professor Alberto Vazques Saa of IMECC-UNICAMP. With the scale factor, the Big Bang itself, a cosmological singularity, ceases to be a necessary condition for the cosmos to begin universal expansion.
From the 1940s onward, scientists guided by Einstein’s theory of general relativity constructed a detailed model of the evolution of the universe since the Big Bang.
The model could lead to three possible outcomes: the infinite expansion of the universe at ever-higher velocities; the stagnation of the expansion in a permanent basis; or an inverted process of retraction caused by the gravitational attraction exerted by the mass of the universe, known as the Big Crunch.
“Eliminating the singularity or Big Bang brings back the bouncing universe on to the theoretical stage of cosmology. The absence of a singularity at the start of spacetime opens up the possibility that vestiges of a previous contraction phase may have withstood the phase change and may still be with us in the ongoing expansion of the universe,” Neves said.
How do you test the hypothesis of a Big Bang that did not start with a singularity? “By looking for traces of the events in a contraction phase that may have remained in the ongoing expansion phase. The candidates include remnants of black holes from a previous phase of universal contraction that may have survived the bounce,” Neves said.