At each epoch, a batch of actions is being sampled from a multivariate Gaussian distribution N (µ θ , Σ) parameterized by the policy network µ θ with parameters θ.The policy network is an actor-critic architecture implemented as a neural network which outputs the parameter µ θ . The diagonal covariance matrix Σ is non-parameterized and is specified as Σ = σI 2 with σ being the standard deviation parameter. The transition dynamics is defined as follows: