What are necessary and sufficient conditions for the Bellman Equation to be solvable?

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I am studying Markov Rewaed Processes right now, and I wish to gain a deeper understanding of the Bellman equation's relationship with them.

I learned the Bellman equation in the following form:

$v = R + \gamma Pv$

Here, $R$ is the reward vector, $P$ the transition probability matrix, $\gamma$ is the discount factor and $v$ is the value we are trying to find/assign. The equation can be rearranged to

$v = (I - \gamma P)^{-1} R$

However, this rearrangement is only possible if (I - γP) is invertible. Is there a concise way to state the conditions under which this is the case?