MULTIVERSES
Level I Multiverse
A generic prediction of cosmic inflation is an infinite ergodic universe, which, by its infinity, must contain Hubble volumes that contemplate all initial conditions.An infinite universe should encompass an infinite number of Hubble volumes, all of them with laws and physical constants equal to ours. However, almost all of them will be different from our Hubble volume in terms of configurations such as the distribution of matter in volume.
Level II Multiverse
In the theory of chaotic eternal inflation, a variant of cosmic inflation theory, the multiverse as a whole stretches and will continue to do so forever; However, some regions of space cease to dilate, forming distinct bubbles.
Such bubbles are Level I embryos of infinite size filled with matter deposited by the energy of the field that caused inflation.
Unlike the Level I multiverse, in the Level II multiverse, the different bubbles (universes) vary not only in their initial conditions but also in aspects as relevant as the dimensions of spacetime, the qualities of elementary particles, and the values taken by the Physical constants. The various bubbles may experience different spontaneous ruptures of symmetry, which translates into disparate properties universes.
Level III Multiverse
Quantum mechanics claims that certain observations can not be absolutely predicted; Instead, there are a variety of possible observations, each with a different probability. According to the IMM, each of these possible observations equals a different universe; The quantum random processes cause the branching of the universe into multiple copies, one for each possible universe. This interpretation conceives an enormous number of parallel universes; These universes are "elsewhere" different from ordinary space.
The Level IV multiverse considers that all mathematical structures also exist physically. Consequently, this level postulates the existence of all universes that can be defined by mathematical structures. Residing out of space and time, most of them are void of observers. Thus, while in the Level I, Level II and Level III multivers the initial conditional and physical constants vary and the fundamental laws remain unchanged. In the Level IV multiverse, the latter also change.
https://www.youtube.com/watch?v=fVaS6oXG8qo&t=1s
