What's the difference between MULTIVERSE theory in cosmology and MODAL REALISM in metaphysics?

Question

People insists they are different, but I don't really see why they can't be reduced to one another.

Answer 1

they are different.

in modal realism the six central doctrines about possible worlds are:

   1. Possible worlds exist — they are just as real as our world;

   2. Possible worlds are the same sort of things as our world — they differ in content, not in kind;

   3. Possible worlds cannot be reduced to something more basic — they are irreducible entities in their own right.

   4. "Actual" is indexical. When we distinguish our world from others by claiming that it alone is actual, we mean only that it is ours — we live here.

   5. Possible worlds are unified by the spatiotemporal interrelations of their parts; possible worlds are spatiotemporally isolated from each other.

   6. Possible worlds are causally isolated from each other.

but in multiverse theory in physics, quantum mechanics or M-theory the parallel universes are not seperate and independent from each other but just a result of infinitely many possibilities of things in each universe. in modal reality they differ in content but in multiverse theory they don't and.....

Answer 2

i have NO CLUE!! this is for only smart pple. and im clearly not smart

Answer 3

There is no generally accepted multiverse theory in cosmology. As far as metaphysics is concerned, the philosophy department is down the hall.