Parallel Universes

Simple item page
dc.creatorTegmark, Max
dc.date2003-02-07
dc.date.accessioned2026-07-07T06:31:57Z
dc.date.available2026-07-07T06:31:57Z
dc.descriptionI survey physics theories involving parallel universes, which form a natural four-level hierarchy of multiverses allowing progressively greater diversity. Level I: A generic prediction of inflation is an infinite ergodic universe, which contains Hubble volumes realizing all initial conditions - including an identical copy of you about 10^{10^29} meters away. Level II: In chaotic inflation, other thermalized regions may have different effective physical constants, dimensionality and particle content. Level III: In unitary quantum mechanics, other branches of the wavefunction add nothing qualitatively new, which is ironic given that this level has historically been the most controversial. Level IV: Other mathematical structures give different fundamental equations of physics. The key question is not whether parallel universes exist (Level I is the uncontroversial cosmological concordance model), but how many levels there are. I discuss how multiverse models can be falsified and argue that there is a severe "measure problem" that must be solved to make testable predictions at levels II-IV.
dc.description18 pages, 8 figs. A less technical adaptation is scheduled for the May 2003 issue of Scientific American. Version with full-resolution figs at http://www.hep.upenn.edu/~max/multiverse.html
dc.identifierhttps://arxiv.org/abs/astro-ph/0302131
dc.identifierhttp://arxiv.org/abs/astro-ph/0302131
dc.identifierIn "Science and Ultimate Reality: From Quantum to Cosmos", honoring John Wheeler's 90th birthday. J. D. Barrow, P.C.W. Davies, & C.L. Harper eds. Cambridge University Press (2003)
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/98761
dc.subjectAstrophysics
dc.subjectQuantum Physics
dc.titleParallel Universes
dc.typetext

Files

Collections

arXiv