Research sheds light on new model of cosmological dark matter

Researchers at the University of Newcastle used insights gained from the study of ultracold atomic posit Einstein condensates to analyze the behavior of the elusive dark matter, which has recently caught the attention of cosmologists.

They found that the physical state of the core of an obscure dark matter halo, the gravitationally bound structures thought to form galaxies like ours, is similar to Bose-Einstein condensates (BECs) created in laboratory atomic traps.

The interdisciplinary team found that the fuzzy dark matter surrounding the halo centers is in a turbulent state, and the eddies and fluctuations prevent coherence throughout the halo. These properties distinguish the more widely accepted cold dark matter model from fuzzy dark matter, which lacks coherent features and quantum spins.

Scientists have demonstrated that the centers of dark matter halos in this new fuzzy dark matter model are practically giant BECs, spanning not millions of meters (micrometers) like conventional cold nuclear systems, but thousands of light-years (equivalent to tens of millions to billions of kilometers), covering the centers of galaxies. , and a characteristic property of quantum systems and PECs is called coherence.

The study also describes the internal motions of the outer haloes and the kinetic energy of the dark matter there, which creates a complex tangle of quantum spins with characteristic density profiles at their cores.

Their findings are published in the journal Monthly Notices of the Royal Astronomical Society.

A meeting of two fields

Cosmology deals with the largest scales in nature, from regions of galaxies and clusters to the entire observable universe. Cosmologists make observations of the universe, obviously unable to perform experiments, and the main natural force they are concerned with is gravity. Such observations suggest that most of the stuff that makes up the universe, unlike the stuff that makes up humans, planets and stars, is made up of an unknown substance, for lack of a better term, dark matter.

Ultracold nuclear physics, on the other hand, describes the behavior of clouds of atoms such as rubidium, potassium, and sodium gases, typically in laboratories around the world more than a millionth of a degree above absolute zero, and investigates phenomena that exhibit quantum nature. matter.

Newcastle University Dr. Led by Gerasimos Rigopoulos and Professor Nick Brugakis, theorists in cosmology and ultracold nuclear physics respectively, the study brought together these two fields. Research fellow in the group Dr. I-Kong (Gary) Liu, who recently completed a Marie Curie Fellowship, Dr. Alex Soto and Ph.D. Student Milos Indjin.

Senior Lecturer in Applied Mathematics Dr. „Various dark matter has already been studied by cosmologists for a few years, but our work uses ideas from the long-standing study of BEC dynamics,” says Rigopoulos. The ultimate goal is to create ways to monitor.”

„I’ve always been open to interdisciplinary approaches in physics, and it’s a perfect problem to tackle from such a perspective. It took a while to establish a common language, but when we conceived this project, we could see from the beginning. When you step out of your comfort zone and try to see things from a new perspective The rewards can be reaped. I think our persistence has paid off, and we’ve only scratched the surface of what such a collaboration can do.”

Professor Brugakis, a professor of quantum physics and a strong advocate of the universality of such forms of quantum coherence, added, „It’s fantastic to see another plausible realization of a system exhibiting Bose-Einstein condensation: it’s incredible to see. We’re now dealing with a large system beyond the imagination of those who first studied this phenomenon in controlled laboratory settings.” .”

„While creating the ability to mimic gravity in controlled laboratory settings is challenging/unknown in three-dimensional settings, similar challenges that initially seemed impossible were eventually encountered in such experimental settings. Just the prospect, if not the most likely, of future possibilities. Creating lab settings that mimic some aspect of the distribution of matter in the universe is in its own right. Exciting.”

„Furthermore, although a theoretical playground, modeling a new system will test the detailed expertise gained from laboratory condensers and look forward to future observational experiments in cosmology.”

Future research will focus on possible ways to observe such features of obscure dark matter, thus subjecting this model to more detailed observational study.

The scientists have already completed a study and are preparing a series of publications showing the theoretical consistency of the equations governing the fuzzy dark matter model used to study how Bose-Einstein condensation forms in the laboratory as nuclear gases cool. Close to absolute zero.

Using insights from currently established theories designed to describe cold atoms, conventional cold dark matter and new fuzzy dark matter models are mathematically integrated, while discoveries such as impacts and long-term observational studies.