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arXiv · 2512.06078

Temporal correlations and chaos from spacetime kernel

Rathindra Nath Das·Arnab Kundu·Matheus H. Martins Costa·Nemai Chandra Sarkar
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Abstract

We develop a finite-dimensional formulation of the recently introduced notion of ``timelike entanglement'', defined in terms of two-point functions between operators supported on different Cauchy slices. Using a local orthonormal operator basis, we recast this construction in terms of a generalized response tensor. Building on this, we introduce a generalized spacetime density kernel (GSDK) corresponding to higher-point correlation functions, including time-ordered as well as out-of-time-ordered correlators. We show that the Haar-averaged $(2N)$-point function yields the $(2N)$-th moment of the spectral form factor (SFF), evaluated at an $N$-enhanced effective temperature. The correlation functions of the GSDK operators also yield the SFF, with an effective $(1/N)$-reduction of the physical time-scales. The GSDK places both scrambling diagnostics and spectral statistics on a similar footing and clarifies how higher-point correlators and non-trivial time ordering capture fine-grained dynamical information of a quantum system.

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Rathindra Nath Das, Arnab Kundu, Matheus H. Martins Costa, Nemai Chandra Sarkar. 2025-12-05. Temporal correlations and chaos from spacetime kernel. https://arxiv.org/abs/2512.06078

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