the concept of "maximum energy" for dark matter is not well-defined. Dark matter refers to a hypothetical form of matter that does not interact with light or electromagnetic radiation, making it difficult to detect directly. It interacts with ordinary matter only through gravitational forces.
Dark matter particles are typically thought to be non-relativistic, meaning they move at speeds much lower than the speed of light. The energy of dark matter particles is determined by their mass and velocity. However, since dark matter has not been directly observed or fully understood, its exact properties, including its mass range and maximum energy, remain uncertain.
Scientists have proposed various dark matter particle candidates, such as weakly interacting massive particles (WIMPs), axions, or sterile neutrinos, among others. The masses and energy scales associated with these candidates can vary widely. Experimental efforts, such as the Large Hadron Collider (LHC) and dedicated dark matter detectors, aim to search for and study dark matter particles, which may provide more insights into their properties in the future.
and there may have been advancements or discoveries in the field since then.