David Deutsch

British physicist at Oxford, a founding figure of quantum computing (the 1985 quantum Turing machine paper) who in 1991 proposed a quantum-mechanical model of closed timelike curves (D-CTCs), applying ordinary unitary evolution with a self-consistency condition imposed at the loop. Not to be confused with Karl Deutsch, the political scientist who appears elsewhere in this vault under the same surname.

Matters to this vault as the contrast case the entire postselected-closed-timelike-curve (P-CTC) computation literature measures itself against: Lloyd et al.'s 2010 P-CTC construction is explicitly built as a "physically distinct alternative" to Deutsch's own model, and the two branches are compared for computational power in the surrounding literature (D-CTCs shown equal to PSPACE by Aaronson and Watrous, 2009; P-CTCs shown equal to PP by Lloyd et al.).

References

• claim-lloyd-et-al-2010-p-ctc-paper-cites-aharonov-weak-value-and-aaronson-postselection