A novel application of quantum speed limit in string theory

In this work, we investigate the implications of a quantum speed limit in the bosonic string theory. We adopt a novel approach to the time problem on the world-sheet based on Fisher information and derive a minimum time required for a particle state to evolve into another. This is achieved using both the Mandelstam–Tamm bound and the Margolus–Levitin bound, which are collectively used to define the quantum speed limit. The existence of such a limit implies that any interaction in string theory must be smeared over a finite time interval, enforcing nonlocality in the corresponding effective quantum field theory. Since nonlocal quantum field theories are known to be finite, this suggests that divergences in effective quantum field theories could be naturally resolved due to the quantum speed limit in string theory.