Theoretical physicists present an alternative to the WIMP paradigm
Only a small part of the universe is made up of visible matter. From a distance, most of it is invisible and consists of dark matter and dark energy. Very little is known about dark energy, but there are many theories and experiments about the existence of dark matter designed to find these as yet unknown particles. Scientists from Johannes Gutenberg University Mainz (JGU) in Germany have now proposed a new theory for how dark matter may have formed soon after the origin of the universe. This new model offers an alternative to the WIMP paradigm which is the subject of various experiments in current research.
Dark matter is present throughout the universe, forming galaxies and the largest known structures in the cosmos. It makes up about 23% of our universe, while the particles visible to us that make up stars, planets, and even life on Earth make up only about 4%. The current hypothesis is that dark matter is a cosmological relic that has essentially remained stable since its creation. “We challenged this hypothesis, showing that at the beginning of the universe, dark matter may have been unstable,” explained Dr. Michael Baker of the Theoretical High Energy Physics (THEP) group at the Institute of Physics. JGU. This instability also indicates the existence of a new mechanism that explains the observed amount of dark matter in the cosmos.
The stability of dark matter is generally explained by a principle of symmetry. However, in their paper, Dr. Michael Baker and Professor Joachim Kopp demonstrate that the universe may have gone through a phase in which this symmetry was broken. This would mean that it is possible for the hypothetical dark matter particle to disintegrate. During the electroweak phase transition, the symmetry that stabilizes dark matter would have been restored, allowing it to continue to exist in the universe until the present day.
With their new theory, Baker and Kopp have introduced a new principle into the debate over the nature of dark matter that offers an alternative to the widely accepted WIMP theory. Until now, WIMPs, or Weakly Interacting Massive Particles, have been considered the most likely components of dark matter, and experiments involving heavily shielded underground detectors have been conducted to search for them. “The absence of any convincing signals led us to look for alternatives to the WIMP paradigm,” Kopp said.
The two physicists claim that the new mechanism they propose could be linked to the apparent imbalance between matter and antimatter in the cosmos and could leave an imprint that would be detected in future gravitational wave experiments. In their article published in the scientific journal Physical examination lettersBaker and Kopp also indicate the prospects of finding proof of their new principle at CERN’s LHC particle accelerator and other experimental facilities.