First proof that gravity can exist without mass

June 7 () –

An astrophysicist has described, for the first time, how gravity can exist without mass, providing an alternative theory that could potentially mitigate the need for dark matter.

Dark matter is a hypothetical form of matter given off by gravitational effects that cannot be explained by general relativity unless there is more matter present in the universe than can be seen. It remains virtually as mysterious as it was almost a century ago, when Dutch astronomer Jan Oort first suggested it in 1932 to explain the so-called “missing mass” necessary for things like galaxies to clump together.

“My own inspiration came from my search for another solution to the gravitational field equations of general relativity (the simplified version of which, applicable to the conditions of galaxies and galaxy clusters, is known as the Poisson equation), which gives a finite gravitational force in the absence of any detectable mass,” says it’s a statement Professor Richard Lieu of the University of Alabama in Huntsville (UAH), author of the new research, which has been published in Monthly Notices of the Royal Astronomical Society.

“This initiative is in turn driven by my frustration with the status quo, that is, the notion of the existence of dark matter despite the lack of direct evidence for an entire century.”

The researcher maintains that the “excess” gravity needed to hold a galaxy or cluster together could instead be due to concentric sets of layer-like topological defects in structures commonly found throughout the cosmos and that were likely created during the early universe when a phase transition occurred. A cosmological phase transition is a physical process in which the general state of matter changes as a whole throughout the universe.

“It is currently unclear what precise form of phase transition in the universe could give rise to topological defects of this type,” says Lieu.

“Topological effects are very compact regions of space with a very high density of matter, usually in the form of linear structures known as cosmic strings, although 2D structures such as spherical layers are also possible.

“The layers in my paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass; The total mass of both layers (which is all that can be measured in terms of mass) is exactly zero, but when a star lies above this layer, It experiences a great gravitational force that attracts it towards the center of the layer.

Since the gravitational force fundamentally involves the deformation of space-time itself, it allows all objects to interact with each other, whether they have mass or not. It has been confirmed, for example, that massless photons experience gravitational effects from astronomical objects.

“The gravitational bending of light by a set of singular concentric layers that make up a galaxy or cluster It is because a ray of light is deflected slightly inward (i.e., toward the center of the large-scale structure, or set of layers) when passing through a layer,” Lieu says.

“The total effect of passing through many layers is a finite and measurable total deflection that mimics the presence of a large amount of dark matter very similar to the speed of stellar orbits.

“Both light bending and stellar orbital velocities are the only means by which the strength of the gravitational field in a large-scale structure, whether a galaxy or a galaxy cluster, can be measured. The claim in my paper is that at least the layers he postulates are massless. Therefore, there is no need to perpetuate this seemingly endless search for dark matter“.

Questions for future research will likely focus on how a galaxy or cluster forms through the alignment of these layers, as well as how the evolution of structures occurs.

“This paper does not attempt to address the problem of structure formation. A contentious point is whether the layers were initially flat or even straight strings, but angular momentum rolls them up. There is also the question of how to confirm or refute the proposed layers by observations Of course, the availability of a second solution, even if very suggestive, is not by itself enough to discredit the dark matter hypothesis; it could be an interesting mathematical exercise at best,” Lieu concludes. “But it is the first proof that gravity can exist without mass.”