Einstein-Cartan Portal to Dark Matter

Understand

It is well-known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincar\'e group, which puts gravity on the same footing as the Standard Model fields.

• The resulting theory -- Einstein-Cartan gravity -- inevitably contains four-fermion and scalar-fermion interactions that originate from torsion associated with spin degrees of freedom.
• We show that these interactions lead to a novel mechanism for producing singlet fermions in the Early Universe.
• These fermions can play the role of dark matter particles.