(disclaimer: I've not looked at mamba specifically yet) but state spaces as used current are different from traditional RNNs in a very simple way: the state is

(disclaimer: I've not looked at mamba specifically yet) but state spaces as used current are different from traditional RNNs in a very simple way: the state is linearly (often associatively) accumulated while in RNN the state is passed/accumulated as an input/output of a non-linear function.