THE MULTIVERSE CONTROVERSY

This paper offers a synthesis of the positions in the literature regarding controversies about the multiverse. After re-viewing some simple elements of modern cosmology and its observational limitations, we will present the history ofthe ideas that led, first, to the proposal of the anthropic principle and, years later, to the possible existence of causallydisconnected domains, eventually endowed with their own laws and fundamental constants, not all compatible with theexistence of observers, which were globally baptized with the confusing name of parallel universes or multiverse.