Dark matter

The Pool galaxy cluster is a direct empirical proof of the existence of dark matter. Combined image of the Hubble + Chandra telescopes. Image: Clowe D. et al.

2023: China builds world's deepest dark matter search lab

In early December 2023 China , the world's deepest search laboratory was launched - dark matter a hypothetical form of matter that does not participate in electromagnetic interaction. A research site called China Jinping Underground Laboratory is located at a depth of approximately 2,400 meters under Mount Jinping in the southwestern Chinese province of Sichuan. More. here

2021: Dark matter is denser than thought - this will help in its search

In early 2021, it became known that researchers from the University of Sussex were able to narrow the range of masses in which particles constituting dark matter can be. To more precisely calculate the limits of the mass of particles, the researchers suggested that dark matter is affected by a force alone - quantum gravity^[1] help^[2].

Thus, the authors of the work for the first time in the scientific world used knowledge about quantum gravity to calculate the range of masses of dark matter. Quantum gravity is a field of research that attempts to combine two of Einstein's concepts: quantum physics and the general theory of gravity relativity.

Based on their assumption, the researchers calculated that dark matter particles have a mass of 10^ -3 eV to 10^7 eV (electronvolt). Previously, it was assumed that this range ranges from 10^-24 eV to 10^19 GeV, that is, the substance turned out to be much denser than scientists thought.

The lower limit of mass was calculated based on the possibility of action on particles of unknown force, and the upper - from the lifetime of candidate particles for the role of dark matter. Previously, it was assumed that dark matter can be ultralight or superheavy, but it turns out that these theories are incorrect, unless, of course, it is influenced by some power still unknown to science.

This discovery will help limit the search area for dark matter, but scientists will also be able to reveal the existence of an unknown fifth force in the Universe (of course, if it exists).

It is generally accepted that there are currently four main forces in the universe - fundamental interactions: strong, electromagnetic, weak and gravitational. The discovery of an unknown fifth force so far could even serve as an impetus for the discovery of a new field of physics to study it.

The refinement of the mass range excludes the theory that one of the candidates for the role of dark matter particles is wimps, hypothetical weakly interacting massive particles (the last sensitive experiments limited the mass of wimps to a range from 10^10 to 10^12 eV).

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