Junctions, strings, clocks and gravitational memory in three dimensional dS space

Abstract: We show that non-trivial stringy excitations in Lorentzian three dimensional de Sitter spacetime can be created self-consistently from gravitational memory in the infinite past. In addition to demonstrating that the Nambu-Goto equations for the string emerge from the gravitational junction conditions, we establish the existence of well-behaved solutions corresponding to transient fluctuations of a closed string about the equator which are both borne out of and dissolve to distinct gravitational memory in the infinite past and future, respectively. The solutions of the junction conditions also reveal that a transient string excitation sets up a clock self-consistently without the need of an external observer.