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Related papers: Krylov complexity in conformal field theory

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Krylov complexity, a quantum complexity measure which uniquely characterizes the spread of a quantum state or an operator, has recently been studied in the context of quantum chaos. However, the definitiveness of this measure as a chaos…

Quantum Physics · Physics 2025-09-12 Sreeram PG , J. Bharathi Kannan , Ranjan Modak , S. Aravinda

The dynamics of quantum systems unfolds within a subspace of the state space or operator space, known as the Krylov space. This review presents the use of Krylov subspace methods to provide an efficient description of quantum evolution and…

We study information scrambling -- a spread of initially localized quantum information into the system's many degree of freedom -- in discrete-time quantum walks. We consider out-of-time-ordered correlators (OTOC) and K-complexity as a…

Quantum Physics · Physics 2024-11-07 Himanshu Sahu

We investigate the relationship between Krylov complexity and operator quantum speed limits (OQSLs) of the complexity operator and level repulsion in random/integrable matrices and many-body systems. An enhanced level-repulsion corresponds…

Quantum Physics · Physics 2025-04-29 Ankit Gill , Tapobrata Sarkar

This paper establishes that Krylov complexity contains the entire information about the dynamics of a quantum operator, extending the list of equivalent quantities that can serve this purpose, such as the Lanczos coefficients, the return…

High Energy Physics - Theory · Physics 2026-05-28 Wolfgang Mück

We perform a systematic holographic study of Krylov complexity for a wide class of confining quantum field theories. Using the geometric prescription that identifies the time derivative of the complexity with the proper momentum of a…

High Energy Physics - Theory · Physics 2026-05-28 Ali Fatemiabhari , Carlos Nunez

There are various definitions of the concept of complexity in Quantum Field Theory as well as for finite quantum systems. For several of them there are conjectured holographic bulk duals. In this work we establish an entry in the AdS/CFT…

High Energy Physics - Theory · Physics 2023-09-11 E. Rabinovici , A. Sánchez-Garrido , R. Shir , J. Sonner

We study three prominent diagnostics of chaos and scrambling in the context of two-dimensional conformal field theory: the spectral form factor, out-of-time-ordered correlators, and unitary operator entanglement. With the observation that…

High Energy Physics - Theory · Physics 2020-06-19 Jonah Kudler-Flam , Laimei Nie , Shinsei Ryu

Commonly, the notion of "quantum chaos'' refers to the fast scrambling of information throughout complex quantum systems undergoing unitary evolution. Motivated by the Krylov complexity and the operator growth hypothesis, we demonstrate…

Quantum Physics · Physics 2024-09-19 Eoin Carolan , Anthony Kiely , Steve Campbell , Sebastian Deffner

In Hermitian systems, Krylov complexity has emerged as a powerful diagnostic of quantum dynamics, capable of distinguishing chaotic from integrable phases, in agreement with established probes such as spectral statistics and…

High Energy Physics - Theory · Physics 2026-02-12 Matteo Baggioli , Kyoung-Bum Huh , Hyun-Sik Jeong , Xuhao Jiang , Keun-Young Kim , Juan F. Pedraza

We study the growth and saturation of Krylov spread (K-) complexity under random quantum circuits. In Haar-random unitary evolution, we show that, for large system sizes, K-complexity grows linearly before saturating at a late-time value of…

Quantum Physics · Physics 2025-05-22 Himanshu Sahu , Aranya Bhattacharya , Pingal Pratyush Nath

This work addresses how the growth of invariant operators is influenced by their underlying symmetry structure. For this purpose, we introduce the symmetry-resolved Krylov complexity, which captures the time evolution of each block into…

High Energy Physics - Theory · Physics 2025-10-21 Pawel Caputa , Giuseppe Di Giulio , Tran Quang Loc

We study Krylov complexity in BMN Plane Wave Matrix Model at large mass deformation. We consider various consistent reductions of the matrix model that allow us to perform a Hamiltonian analysis which leads to different notions of the…

High Energy Physics - Theory · Physics 2026-05-26 Dibakar Roychowdhury

Quantum chaos refers to signatures of classical chaos found in the quantum domain. Recently, it has become common to equate the exponential behavior of out-of-time order correlators (OTOCs) with quantum chaos. The quantum-classical…

We extend the concept of Krylov complexity to include general unitary evolutions involving multiple generators. This generalization enables us to formulate a framework for generalized Krylov complexity, which serves as a measure of the…

High Energy Physics - Theory · Physics 2025-08-14 Amin Faraji Astaneh , Niloofar Vardian

We present a general framework in which both Krylov state and operator complexities can be put on the same footing. In our formalism, the Krylov complexity is defined in terms of the density matrix of the associated state which, for the…

High Energy Physics - Theory · Physics 2023-08-30 Mohsen Alishahiha , Souvik Banerjee

We investigate the complexity of states and operators evolved with the modular Hamiltonian by using the Krylov basis. In the first part, we formulate the problem for states and analyse different examples, including quantum mechanics,…

High Energy Physics - Theory · Physics 2023-06-27 Pawel Caputa , Javier M. Magan , Dimitrios Patramanis , Erik Tonni

We study Krylov complexity in Lifshitz-type Dirac field theories with a generic dynamical critical exponent $z$. By computing the Lanczos coefficients for massless and massive cases, we analyze the growth and saturation behavior of Krylov…

High Energy Physics - Theory · Physics 2025-11-11 Hamid R. Imani , Komeil Babaei Velni , M. Reza Mohammadi Mozaffar

We investigate Krylov complexity of the fermion chain operator which consists of multiple Majorana fermions in the double-scaled SYK (DSSYK) model with finite temperature. Using the fact that Krylov complexity is computable from two-point…

High Energy Physics - Theory · Physics 2024-07-19 Takanori Anegawa , Ryota Watanabe

We examine the complexity of quasi-static chaotic open quantum systems. As a prototypical example, we analytically compute the Krylov complexity of a slowly leaking hard-sphere gas using Berry's conjecture. We then connect it to the…

High Energy Physics - Theory · Physics 2023-12-05 Vyshnav Mohan