Indexical uncertainty is irreducible subjective uncertainty induced by anthropically expecting to be in more than one possible future world.
I think the phrase "more than one possible future world" is misleading and should be changed. The paradigmatic cases of indexical uncertainty (including both given examples of the five-AI-clones case and of Everettian quantum mechanics) involve no certainty about which objective possible world is actual, and only involves self-locating uncertainty about my location within a possible world.
So it would be more accurate to say that it is irreducible subjective uncertainty over multiple centered possible worlds or multiple locations with a given possible world.
I think the phrase "more than one possible future world" is misleading and should be changed. The paradigmatic cases of indexical uncertainty (including both given examples of the five-AI-clones case and of Everettian quantum mechanics) involve no certainty about which objective possible world is actual, and only involves self-locating uncertainty about my location within a possible world.
So it would be more accurate to say that it is irreducible subjective uncertainty over multiple centered possible worlds or multiple locations with a given possible world.