Mimetic Dark Matter

Understand

We reformulate Einstein's theory of gravity, isolating the conformal degree of freedom in a covariant way.

• This is done by introducing a physical metric defined in terms of an auxiliary metric and a scalar field appearing through its first derivatives.
• The resulting equations of motion split into a traceless equation obtained through variation with respect to the auxiliary metric and an additional differential equation for the trace part.
• As a result the conformal degree of freedom becomes dynamical even in the absence of matter.