Holographic Krylov complexity in ${\cal N}=4$ SYM
Ali Fatemiabhari, Horatiu Nastase, Dibakar Roychowdhury
TL;DR
The paper develops a holographic Krylov complexity for ${\cal N}=4$ SYM by modeling motion in ${\rm AdS}_5$ sliced by ${\rm AdS}_3$, identifying the ${\rm Sl}(2)$ subsector with motion in the AdS3 subspace. It extends a known relation between the time derivative of Krylov complexity and the proper momentum, $\dot C(t) = -P_{\bar{\rho}}/\epsilon$, to the AdS5 context via a proper-distance coordinate ${\bar{\rho}}$ with $ds^2 = d\bar{\rho}^2$. The analysis first treats the exact AdS3 subspace dual to the ${\rm Sl}(2)$ sector and then generalizes to ${\rm AdS}_5$ sliced by ${\rm AdS}_3$, providing explicit expressions for the canonical momenta and the proper momentum in global and Poincaré coordinates. The results illuminate how holographic Krylov complexity encodes the time evolution of the ${\rm Sl}(2)$ sector and offer a framework for extending to deformed or non-conformal settings, with future work including direct Krylov-complexity calculations in spin-chain realizations and further AdS slicings.
Abstract
We propose and calculate a holographic Krylov complexity in ${\cal N}=4$ SYM via the proper momentum for motion in $AdS_5$ sliced by $AdS_3$. The motion in an $AdS_3$ subgroup corresponds to the Krylov complexity of the $Sl(2)$ subsector. The general motion corresponds to the Krylov complexity of the ${\cal N}=4$ SYM.
