im a little confused about this definition.
Is a staionary markov chain a chain with a stationary distribution (not necessarily unique)?
or the stationary distribution needs to be unique (so the chain is irreducible and positive recurrent) to be a stationary markov chain?
or is something totally different?
Ive read something about being P-invariant under "time translations" but i can not find this definition formally.
any help would be great