I am confused about the relationship between relative state and decoherence in the Many Worlds Interpretation of QM. My understanding of MWI is that as the universal wavefunction evolves, components of it decohere from each other, and when this happens we can think of it as the world spliting into branches and treat the components seperately from that point on because they would be unlikely to interfere with each other.
Now how does relative state fit into this? Is relative state still an important part of the MWI, or is decoherence sufficient for the interpretation?
