Universal wavefunction

The universal wavefunction or the wavefunction of the universe is the wavefunction or quantum state of the entire universe.^[1] It is regarded as the basic physical entity^[2] in the many-worlds interpretation of quantum mechanics,^[3]^[4]^[5]^[6] and finds applications in quantum cosmology. It evolves deterministically according to a wave equation.^[7]

The concept of universal wavefunction was introduced by Hugh Everett in his 1956 PhD thesis draft The Theory of the Universal Wave Function.^[8] It later received investigation from James Hartle and Stephen Hawking^[9] who derived the Hartle–Hawking solution to the Wheeler–deWitt equation to explain the initial conditions of the Big Bang cosmology.

^ Everett [1956]1973, "Theory of the Universal Wavefunction", introduction, pg 8–9
^ Everett 1957, section 3, 2nd paragraph, 1st sentence.
^ Hugh Everett, Relative State Formulation of Quantum Mechanics, Reviews of Modern Physics vol 29, (1957) pp 454–462. An abridged summary of The Theory of the Universal Wavefunction
^ John Archibald Wheeler, Assessment of Everett's "Relative State Formulation of Quantum Theory", Reviews of Modern Physics, vol 29, (1957) pp 463–465
^ Bryce Seligman DeWitt, Quantum Mechanics and Reality, Physics Today,23(9) pp 30–40 (1970) also April 1971 letters followup
^ Bryce Seligman DeWitt, The Many-Universes Interpretation of Quantum Mechanics, Proceedings of the International School of Physics "Enrico Fermi" Coursu IL: Foundations of Quantum Mechanics, Academic Press (1972)
^ Everett [1956]1973, "Theory of the Universal Wavefunction", chapter 6 (e)
^ Bryce Seligman DeWitt, R. Neill Graham, eds, The Many-Worlds Interpretation of Quantum Mechanics, Princeton Series in Physics, Princeton University Press (1973), ISBN 0-691-08131-X Contains the reprint of Everett's thesis: The Theory of the Universal Wave Function, pp 3–140.
^ Stephen W Hawking, James B Hartle "The Wave Function of the Universe," Physical Review D, vol 28, (1983) pp 2960–2975