String theory landscape

In string theory, the string theory landscape (or landscape of vacua) is the collection of possible false vacua,^[1] together comprising a collective "landscape" of choices of parameters governing compactifications.

The term "landscape" comes from the notion of a fitness landscape in evolutionary biology.^[2] It was first applied to cosmology by Lee Smolin in his book The Life of the Cosmos (1997), and was first used in the context of string theory by Leonard Susskind.^[3]

^ The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10⁵⁰⁰. See M. Douglas, "The statistics of string / M theory vacua", JHEP 0305, 46 (2003). arXiv:hep-th/0303194; S. Ashok and M. Douglas, "Counting flux vacua", JHEP 0401, 060 (2004).
^ Baggott, Jim (2018). Quantum Space Loop Quantum Gravity and the Search for the Structure of Space, Time, and the Universe. Oxford University Press. p. 288. ISBN 978-0-19-253681-5.
^ L. Smolin, "Did the universe evolve?", Classical and Quantum Gravity 9, 173–191 (1992). L. Smolin, The Life of the Cosmos (Oxford, 1997)

[Ashok-1] The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10⁵⁰⁰. See M. Douglas, "The statistics of string / M theory vacua", JHEP 0305, 46 (2003). arXiv:hep-th/0303194; S. Ashok and M. Douglas, "Counting flux vacua", JHEP 0401, 060 (2004).

[2] Baggott, Jim (2018). Quantum Space Loop Quantum Gravity and the Search for the Structure of Space, Time, and the Universe. Oxford University Press. p. 288. ISBN 978-0-19-253681-5.

[3] L. Smolin, "Did the universe evolve?", Classical and Quantum Gravity 9, 173–191 (1992). L. Smolin, The Life of the Cosmos (Oxford, 1997)

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