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Dual-unitary brickwork circuits are an exactly-solvable model for many-body chaotic quantum systems, based on 2-site gates which are unitary in both the time and space directions. Prosen has recently described an alternative model called…

Quantum Physics · Physics 2024-07-31 Pieter W. Claeys , Austen Lamacraft , Jamie Vicary

Temporal data, obtained in the setting where it is only possible to observe one time point per experiment, is widely used in different research fields, yet remains insufficiently addressed from the statistical point of view. Such data often…

Methodology · Statistics 2025-03-10 Polina Arsenteva , Mohamed Amine Benadjaoud , Hervé Cardot

We show that, by using the quantum orthogonal functions invariant, we are able to solve a coupled of time dependent harmonic oscillators where all the time dependent frequencies are arbitrary. We do so, by transforming the time dependent…

We present equations of motion (EOMs) for general time-dependent wave functions with exponentially parametrized biorthogonal basis sets. The equations are fully bivariational in the sense of the time-dependent bivariational principle…

Chemical Physics · Physics 2023-05-08 Mads Greisen Højlund , Alberto Zoccante , Ove Christiansen

The nonequilibrium variational-cluster approach is applied to study the real-time dynamics of the double occupancy in the one-dimensional Fermi-Hubbard model after different fast changes of hopping parameters. A simple reference system,…

Strongly Correlated Electrons · Physics 2016-04-15 Felix Hofmann , Martin Eckstein , Michael Potthoff

The ground state pairing correlations in finite fermionic systems are described with a high degree of accuracy within a variational approach based on a combined coupled-cluster and particle-number-projected BCS ansatz. The flexibility of…

Nuclear Theory · Physics 2021-06-02 V. V. Baran , J. Dukelsky

Three fully variational formulations of the complete-active space coupled-cluster (CASCC) method are derived. The formulations include the ability to approximate the model vectors by smooth manifolds, thereby opening up the possibility for…

Chemical Physics · Physics 2023-07-12 Simen Kvaal

We introduce a new class of quantum models with time-dependent Hamiltonians of a special scaling form. By using a couple of time-dependent unitary transformations, the time evolution of these models is expressed in terms of related systems…

Quantum Physics · Physics 2009-11-07 L. Samaj

The gauge bundle of the 4-dim conformal group over an 8-dim base space, called biconformal space, is shown have a consistent interpretation as a scale-invariant phase space. Specifically, we show that a classical Hamiltonian system…

General Relativity and Quantum Cosmology · Physics 2007-05-23 James T. Wheeler

A general dynamical invariant operator for three coupled time-dependent oscillators is derived. Although the obtained invariant operator satisfies the Liouville-von Neumann equation, its mathematical formula is somewhat complicated due to…

Quantum Physics · Physics 2022-12-16 Jeong Ryeol Choi

In this work, we investigate the possibility of improving multireference-driven coupled cluster (CC) approaches with an algorithm that iteratively combines complete active space (CAS) calculations with tailored CC and externally corrected…

Chemical Physics · Physics 2025-03-06 Robin Feldmann , Max Mörchen , Jakub Lang , Michał Lesiuk , Markus Reiher

We study time-dependent coupled-cluster theory in the framework of nuclear physics. Based on Kvaal's bi-variational formulation of this method [S. Kvaal, arXiv:1201.5548], we explicitly demonstrate that observables that commute with the…

Nuclear Theory · Physics 2012-07-04 D. A. Pigg , G. Hagen , H. Nam , T. Papenbrock

An exact invariant operator of time-dependent coupled oscillators is derived using the Liouville-von Neumann equation. The unitary relation between this invariant and the invariant of two uncoupled simple harmonic oscillators is…

Quantum Physics · Physics 2022-10-17 Jeong Ryeol Choi

A rank-invariant clustering of variables is introduced that is based on the predictive strength between groups of variables, i.e., two groups are assigned a high similarity if the variables in the first group contain high predictive…

Methodology · Statistics 2023-12-29 Sebastian Fuchs , Yuping Wang

Multivariate time-dependent data, where multiple features are observed over time for a set of individuals, are increasingly widespread in many application domains. To model these data we need to account for relations among both time…

Methodology · Statistics 2021-04-08 Alessandro Casa , Charles Bouveyron , Elena Erosheva , Giovanna Menardi

This article studies the solutions of time-dependent differential inclusions which is motivated by their utility in the modeling of certain physical systems. The differential inclusion is described by a time-dependent set-valued mapping…

Optimization and Control · Mathematics 2021-07-05 Kanat Camlibel , Luigi Iannelli , Aneel Tanwani

Time-dependent response theories are foundational to the development of algorithms that determine quantum properties of electronic excited states of molecules and periodic systems. They are employed in wave-function, density-functional, and…

Chemical Physics · Physics 2022-11-23 Martín A. Mosquera

In several environmental applications data are functions of time, essentially con- tinuous, observed and recorded discretely, and spatially correlated. Most of the methods for analyzing such data are extensions of spatial statistical tools…

Methodology · Statistics 2011-06-28 Elvira Romano , Antonio Balzanella , Rosanna Verde

Critical phase transitions have proven to be a powerful concept to capture the phenomenology of many systems, including deeply non-equilibrium ones like living systems. The study of these phase transitions has overwhelmingly relied on…

Statistical Mechanics · Physics 2025-12-12 Leone V. Luzzatto , Mathias Casiulis , Stefano Martiniani , István A. Kovács

We compute nuclear response functions by solving the time-dependent A-body Schr\"odinger equation, recording the time-dependent transition moment and extracting spectral information via Fourier transforms. The solution of the time-dependent…