The early universe was a restless place. Space trembled with gravitational waves — ripples in the very fabric of reality. In this churning cauldron, dark matter is thought to have been born. But the newborn particles had no mass: it had to come from somewhere.

Usually, the Higgs field is responsible for mass. The authors of the work took a different path and turned to the Einstein–Cartan theory. In this theory, spacetime not only curves but also twists, like a rubber sheet that not only sags under weight but also screws into a spiral. This twisting (torsion) is created by the spin of matter — the intrinsic rotation of particles. In the early universe, filled with a spinor condensate, a kind of "foam" of particles with aligned spins, torsion becomes significant. It is this torsion that bestows mass on the emerging fermions.

Such a mechanism leaves no freedom for parameter tuning. The abundance of dark matter (how much of it exists in the universe) is predicted unambiguously: it depends only on the expansion rate at that distant instant. Moreover, the theory permits only particles with spin 1/2 (fermions like the electron, but without charge). No more exotic options. Dark matter in this picture is not a mysterious sector with a host of new fields, but a simple consequence of geometry.

Thus, the birth of dark matter ceases to be a story with an unknown ending. Everything is decided by the dance of spacetime: its trembling generates particles, and its internal torsion makes them massive. Perhaps the key to the invisible substance of the cosmos is hidden not in new particles, but in how the vacuum itself bends and twists.