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The effective approach to the foundation of the nonequilibrium statistical mechanics on the basis of dynamics was formulated by Bogoliubov in his seminal works. His ideas of reduced description were proved as very powerful and found a broad…

Statistical Mechanics · Physics 2019-12-02 A. L. Kuzemsky

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the…

Quantum Physics · Physics 2009-11-13 Xiao Zheng , Fan Wang , Chi Yung Yam , Yan Mo , GuanHua Chen

We investigate a new representation of general operators by means of sums of shifted Gabor multipliers. These representations arise by studying the matrix of an operator with respect to a Gabor frame. Each shifted Gabor multiplier…

Functional Analysis · Mathematics 2011-07-12 Karlheinz Groechenig

Using the Bloch representation of an N-dimensional quantum system and immediate results from quantum stochastic calculus, we establish a closed formula for the Bloch vector, hence also for the density operator, of a quantum system following…

Quantum Physics · Physics 2009-11-10 D. Salgado , J. L. Sanchez-Gomez

A convenient way to represent a nonlinear input-output system in control theory is via a Chen-Fliess functional expansion or Fliess operator. The general goal of this paper is to describe how to approximate Fliess operators with iterated…

Optimization and Control · Mathematics 2017-10-11 W. Steven Gray , Luis A. Duffaut Espinosa , Kurusch Ebrahimi-Fard

We formulate a general framework for the study of operator systems arising from discrete groups. We study in detail the operator system of the free group on $n$ generators, as well as the operator systems of the free products of finitely…

Operator Algebras · Mathematics 2012-09-07 Douglas Farenick , Ali S. Kavruk , Vern I. Paulsen , Ivan G. Todorov

We study the complexity of closure operators, with applications to machine learning and decision theory. In machine learning, closure operators emerge naturally in data classification and clustering. In decision theory, they can model…

Theoretical Economics · Economics 2022-05-25 Hamed Hamze Bajgiran , Federico Echenique

In this paper, subnormal operators, not necessarily bounded, are discussed as generalized observables. In order to describe not only the information about the probability distribution of the output data of their measurement but also a…

Quantum Physics · Physics 2009-11-06 Masahito Hayashi , Fuminori Sakaguchi

A number of physically intuitive results for the calculation of multi-time correlations in phase-space representations of quantum mechanics are obtained. They relate time-dependent stochastic samples to multi-time observables, and rely on…

Quantum Physics · Physics 2021-05-12 Piotr Deuar

We provide a new formulation of Time-Dependent Density Functional Theory (TDDFT) based on the geometric structure of the set of states constrained to have a fixed density. Orbital-free TDDFT is formulated using a hydrodynamics equation…

This paper explores the global properties of time-independent systems of operators in the framework of Gelfand-Shilov spaces. Our main results provide both necessary and sufficient conditions for global solvability and global…

Analysis of PDEs · Mathematics 2024-03-11 Fernando de Ávila Silva , Marco Cappiello , Alexandre Kirilov

In the time-dependent simulation of pure states dealing with transport in open quantum systems, the initial state is located outside of the active region of interest. Using the superposition principle and the analytical knowledge of the…

Quantum Physics · Physics 2014-10-15 Fabio L. Traversa , Zhen Zhan , Xavier Oriols

The concept of time-coarsened density matrix for open systems has frequently featured in equilibrium and non-equilibrium statistical mechanics, without being probed as to the detailed consequences of the time averaging procedure. In this…

Statistical Mechanics · Physics 2018-09-11 Robert Englman , Asher Yahalom

In this paper, we characterize complementable operators and provide more precise expressions for the Schur complement of these operators using a single Douglas solution. We demonstrate the existence of subspaces where the given operator is…

Functional Analysis · Mathematics 2024-06-18 Sachin Manjunath Naik , P. Sam Johnson

To understand typical dynamics of an open quantum system in continuous time, we introduce an ensemble of random Lindblad operators, which generate Markovian completely positive evolution in the space of density matrices. Spectral properties…

Prediction and optimisation of a wheel loader's dynamic behaviour is a challenge due to tightly coupled, non-linear subsystems of different technical domains. Furthermore, a simulation regarding performance, efficiency, and operability…

Computational Engineering, Finance, and Science · Computer Science 2011-08-30 Reno Filla

We study convergence of the following discrete-time non-linear dynamical system: n agents are located in R^d and at every time step, each moves synchronously to the average location of all agents within a unit distance of it. This popularly…

Data Structures and Algorithms · Computer Science 2012-11-09 Arnab Bhattacharyya , Mark Braverman , Bernard Chazelle , Huy L. Nguyen

We determine the conditions for the equivalence between the multi-time expectation values of a general finite-dimensional open quantum system when interacting with, respectively, an environment undergoing a free unitary evolution or a…

Quantum Physics · Physics 2023-08-15 A. Smirne , D. Tamascelli , J. Lim , M. B. Plenio , S. F. Huelga

$\mathcal{PT}$-symmetric system has attracted extensive attention in recent years because of its unique properties and applications. How to simulate $\mathcal{PT}$-symmetric system in traditional quantum mechanical system has not only…

Quantum Physics · Physics 2022-11-01 Xiaogang Li , Chao Zheng , Jiancun Gao , Guilu Long

Transition Probability (fidelity) for pairs of density operators can be defined as "functor" in the hierarchy of "all" quantum systems and also within any quantum system. The introduction of "amplitudes" for density operators allows for a…

Quantum Physics · Physics 2016-04-08 Armin Uhlmann