They penetrate the Earth: the most powerful cosmic rays in the universe are occurring right next to us.

A new theory suggests that the most powerful cosmic rays striking our planet may not originate from distant regions of the Universe, but rather from our own galaxy. According to astrophysicists, the highest energy cosmic rays are produced by the annihilation of heavy particles of an exotic form of dark matter. This research has been published on the arXiv preprint server, as reported by Live Science.

What is Dark Matter?

What are Cosmic Rays?

Cosmic rays are streams of high-energy particles that constantly travel through space and collide with our planet. They are primarily composed of protons, but can sometimes include nuclei of chemical elements such as helium and even iron. Cosmic rays move through space at nearly the speed of light, with the fastest among them having energies trillions of times greater than those of the most powerful particle accelerators on Earth.

Astrophysicists believe that most cosmic rays are generated by various energetic events: these include supernova explosions, star mergers, and the absorption of matter by black holes.

However, scientists do not fully understand the origins of the highest energy cosmic rays. While there are many potential sources for their creation, all are located billions of light-years away from us. In this scenario, the most powerful cosmic rays should lose energy while traversing such vast distances before reaching Earth. Therefore, the authors of the study propose that these cosmic rays originate much closer to Earth than previously thought, with their source located in our galaxy, the Milky Way.

Exotic Form of Dark Matter and the Most Powerful Cosmic Rays

This new theory from astrophysicists posits that an exotic form of dark matter is the source of the most powerful cosmic rays. Specifically, the theory suggests that part of dark matter consists of very heavy particles, whose mass far exceeds that of the heaviest particle of ordinary matter in the Universe known as the true quark. Quarks make up protons and neutrons, which are the foundation of all atoms.

Astrophysicists believe that the heavy dark matter particle, called a scalaron, was created in the very first moments after the Big Bang during cosmic inflation. At that time, the Universe expanded by quintillions of times in a fraction of a second.

Scientists think that scalarons may collide with each other, resulting in their mutual annihilation, which leads to the release of a significant amount of energy and the emergence of the most powerful cosmic rays. Given that scalarons are thought to be very abundant in the Universe, they could be responsible for creating the highest energy cosmic rays even within our galaxy. However, this still needs to be confirmed by observing the effects of dark matter on the cosmos, which is quite challenging.

There is also another hurdle. If scalarons exist and formed shortly after the Big Bang, then a revision of Einstein's general theory of relativity may be required.