Thoughts on Defining the Multiverse

Understand

The possibility that the multiverse corresponds to physical reality deserves serious investigation.

• Having three different important theories,(quantum mechanics, string theory and inflation), predict the existence of the multiverse is hardly coincidental.
• I argue that the existence of the multiverse must be expected from the underlying fundamental theory or else we can not meaningfully address the puzzle of the initial conditions.
• In this view, the extension of our current cosmology to a multiverse framework becomes an extension of the Copernican principle to nature.