No Big Bang? Quantum equation predicts universe has no beginning

A novel model that employs quantum correction terms to extend Einstein's theory of general relativity suggests that the universe may have lived forever. The model might simultaneously address several issues by taking into consideration dark matter and dark energy.

According to general relativity, the universe is 13.8 billion years old, which is the generally accepted age. All of existence is believed to have originated in a single, singularity-like point that was infinitely dense. The universe didn't actually start until this point started to expand in a "Big Bang".

Although the equations of general relativity directly and ineluctably lead to the Big Bang singularity, some scientists find this to be problematic because the math can only explain what occurred immediately after the singularity—not at or before it.

Because the laws of physics seem to be violated there, Ahmed Farag Ali of Benha University and the Zewail City of Science and Technology in Egypt told that the Big Bang singularity is the most significant issue with general relativity.

In an article that was recently published in Physics Letters B, Ali and coauthor Saurya Das from the University of Lethbridge in Alberta, Canada, demonstrated how their novel theory—in which the cosmos has no origin and no end—can resolve the Big Bang singularity.

Old Ideas Revisited

The physicists stress that they do not arbitrarily apply their quantum correction terms to try to particularly get rid of the Big Bang singularity. Their work is based on concepts put out by David Bohm, a theoretical physicist also noted for his contributions to physics philosophy. Beginning in the 1950s, Bohm investigated using quantum trajectories in place of conventional geodesics (the shortest route between two locations on a curved surface).

In their study, physicists Ali and Das Das applied these Bohmian trajectories to an equation created at Presidency University in Kolkata, India, in the 1950s by physicist Amal Kumar Raychaudhuri. When Das attended that university as an undergraduate student in the 1990s, Raychaudhuri was also his professor.

The quantum-corrected Friedmann equations, which describe the expansion and evolution of the universe (including the Big Bang) within the setting of general relativity, were developed by Ali and Das using the quantum-corrected Raychaudhuri equation. The model incorporates aspects of both quantum theory and general relativity, despite not being a true theory of quantum gravity. In addition, Ali and Das anticipate that their findings will hold true whether or not a complete theory of quantum gravity is developed.

No Singularities Nor Dark Stuff

The new model does not predict a "big crunch" singularity in addition to not forecasting a huge Bang singularity. According to general relativity, the cosmos might begin to contract before collapsing massively in on itself to form an impossibly dense point once more.

In their study, Ali and Das describe how a crucial distinction between Bohmian trajectories and classical geodesics allows their model to avoid singularities. Singularities are the places where classical geodesics finally converge and cross each other. Singularities do not arise in the equations because Bohmian trajectories do not intersect one another.

The researchers clarify that the quantum corrections can be viewed as a radiation term and a cosmological constant term (without the necessity for dark energy). These conditions maintain the universe's limited size, giving it an infinite age. Additionally, the terms provide predictions that nearly match the cosmological constant and cosmic density as observed today.

New Gravity Particle

The model states that there is a quantum fluid at the center of the universe. Theoretical massless particles called gravitons, which mediate the gravitational force, are thought to make up this fluid, according to the scientists. The existence of gravitons is regarded to be crucial to a quantum gravity theory.

Further support for this model has been provided in a companion study by Das and another colleague, Rajat Bhaduri of McMaster University in Canada. They demonstrate that gravitons can create the Bose-Einstein condensate, which bears the names of both Einstein and Satyendranath Bose, a physicist from India.

The physicists intend to conduct a more thorough analysis of their concept in the future since it has the potential to explain dark matter and dark energy as well as the singularity that results from the Big Bang. Small inhomogeneous and anisotropic perturbations will be taken into consideration when they perform their analysis in the future, but they do not anticipate that these perturbations will have a large impact on the outcomes.

It is gratifying to see that such simple fixes have the ability to address so many problems at once, Das added.

Reference(s): Research paper, arXiv

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