Momentum-Krylov complexity correspondence
Zhong-Ying Fan
TL;DR
The paper proposes a momentum-Krylov complexity correspondence, linking the growth rate of Krylov complexity in the boundary to the radial momentum of an infalling bulk particle in AdS/CFT. By formulating dK/dt = P and computing K for various AdS black hole backgrounds, the authors demonstrate universal early quadratic and late-time exponential growth, with an exact BTZ/CFT2 match at finite temperature. Their testing across AdS vacua and higher-dimensional black holes reveals dimensional nuances but preserves key late-time universality, while also discussing connections to circuit complexity. The work provides a compelling approximate dual for Krylov complexity and motivates further exploration of refined momentum concepts and global charge extensions.
Abstract
In this work, we relate the growth rate of Krylov complexity in the boundary to the radial momentum of an infalling particle in AdS geometry. We show that in general AdS black hole background, our proposal captures the universal behaviors of Krylov complexity at both initial and late times. Hence it can be generally considered as an approximate dual of the Krylov complexity at least in diverse dimensions. Remarkably, for BTZ black holes, our holographic Krylov complexity perfectly matches with that of CFT$_2$ at finite temperatures.
