Cosmological Constant, Inflaton, and Dark Matter all Naturally Originated from Poincaré Gauge Gravity

We propose a cosmological model in the framework of Poincaré gauge gravity, in which cosmological constant, inflaton, and dark matter candidate all naturally originate. Cosmological constant originates in the process of breaking of the Poincaré symmetries down to the Lorentz symmetries. We select a gauge Lagrangian without any additional matter fields, which can be regarded as a minimum extension of general relativity with two more massive modes from the Lorentz connection. Numerical analysis shows that the scalar dominates a slow-rolling inflation and the pseudo-scalar behaves as a dark matter candidate.