The Perfect Hyperfluid of Metric-Affine Gravity: The Foundation

Understand

We set the foundation and formulate the Perfect (Ideal) Hyperfluid.

• The latter represents the natural generalization of the usual perfect fluid structure where now the microscopic characteristics of matter (spin, shear, dilation) are also taken into account, sourcing a non-Riemannian arena (i.e spacetime torsion and non-metricity) for Metric-Affine Gravity.
• We derive the energy tensors of this Hyperfluid structure and subsequently present the conservation laws obeyed by them.
• Finally, we consider a Cosmological application of this Perfect Hyperfluid and classify some possible forms of this fluid structure.