A new hypothesis claims that our universe is a bubble in an extra dimension

Many different universe models have been developed over the years. Models that attempted to respond to some of the great mysteries of the cosmos and to explain all the phenomena that are manifested within it, in a logical and rational way. Albert Einstein proposed a cyclical model according to which the universe would expand and contract, giving rise to the death and birth of an infinite number of universes. Today, a team of researchers from the University of Uppsala (Sweden) propose a new model that seems to explain the concept of dark energy and in turn explain the accelerated expansion of the cosmos.

Since 1998 it has been known that the universe expands at an accelerated rate rather than at a constant rate, it does this by increasing the speed as the distance increases, following the Hubble constant. This phenomenon can only be explained by dark energy, a form of energy that wouldn’t interact with any kind of matter or force, with the only exception when opposing gravity; as gravity forms 68.3% of everything in the universe.Given that dark energy is homogeneously distributed throughout the universe and remains a constant, it would be the main cause of the acceleration that the universe undergoes as it expands.

The Uppsala team published its work in Physical Review Letters, proposing a model that is based on a new approach to string theory to explain expansion. According to the new structural approach, our universe would be “mounted” on an expanding bubble. It would be placed on the edge or surface of this bubble and the growth would occur in an extra dimension. All matter in the universe would correspond to the ends of the strings extending into an extra dimension and all the dark energy would be the manifestation of the expansive nature of that bubble. Researchers support that this type of bubble could exist within the framework of string theory and that our universe in which the bubble exists may not be the only one. There are other bubble universes that would form the so-called multiverse.

String theory, the solution to all our problems

According to the Supernova Cosmology Project, dark energy has been one of the most elusive concepts for physics to this day. In search of a satisfactory explanation, the world’s scientists had placed their hopes on the well-known string theory.  According to string theory, all existing matter in the universe is formed by small entities that vibrate similar to strings,that would need more spatial dimensions in addition to the three already existing ones. Although in recent years numerous models have been developed based on string theory, that sought out to explain dark energy, they have been discarded and criticized for not being considered viable.  



The research of Souvik Banerjee, Ulf Danielsson, Giuseppe Dibitetto, Suvendu Giri and Marjorie Schillo proposes a new point of view that allows a different approach to the creation and future of the universe.

According to the new point of view, the two great currents, could lead to dark energy overcoming any other force of attraction and end up annihilating the atoms and destroying the universe (Big Rip) or that this dissipates and causes a super concentration of matter that leads to another Big Bang (Big Crunch). To top things off, the team believes their new model "could pave the way for string theory testing methods.

Reference: Souvik Banerjee, Ulf Danielsson, Giuseppe Dibitetto, Suvendu Giri & Marjorie Schillo: 'Emergent de Sitter Cosmology from Decaying Anti-de Sitter Space'. Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.121.261301.



Continue reading

#}