Nikolova, A.; Brennen, G.K.; Osborne, T.J.; Milburn, G.J.; Stace, T.M.
(College Park, MD : American Physical Society, 2018)
In a seminal paper [Phys. Rev. D 27, 2885 (1983)], Page and Wootters suggest that time evolution could be described solely in terms of correlations between systems and clocks, as a means of dealing with the “problem of ...