English
Related papers

Related papers: Ordered Quantization and the Ehrenfest Time Scale

200 papers

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. In this way, a physical clock with discrete…

Quantum Physics · Physics 2007-05-23 H. -T. Elze

The aim of this short note is to show that Denoising Diffusion Probabilistic Model DDPM, a non-homogeneous discrete-time Markov process, can be represented by a time-homogeneous continuous-time Markov process observed at non-uniformly…

Machine Learning · Statistics 2023-11-30 Javier E. Santos , Yen Ting Lin

This paper generalizes the quantum amplitude amplification and amplitude estimation algorithms to work with non-boolean oracles. The action of a non-boolean oracle $U_\varphi$ on an eigenstate $|x\rangle$ is to apply a state-dependent…

Quantum Physics · Physics 2021-02-10 Prasanth Shyamsundar

In accordance with the fact that quantum measurements are described in terms of positive operator measures (POMs), we consider certain aspects of a quantization scheme in which a classical variable $f:\R^2\to \R$ is associated with a unique…

Quantum Physics · Physics 2015-06-26 J. Kiukas , P. Lahti

Thermalization of classical fields is investigated in a \phi^4 scalar field theory in 1+1 dimensions, discretized on a lattice. We numerically integrate the classical equations of motion using initial conditions sampled from various…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gert Aarts , Gian Franco Bonini , Christof Wetterich

Recent experimental advances have inspired the development of theoretical tools to describe the non-equilibrium dynamics of quantum systems. Among them an exact representation of quantum spin systems in terms of classical stochastic…

Quantum Physics · Physics 2023-04-19 Gennaro Tucci , Stefano De Nicola , Sascha Wald , Andrea Gambassi

In this paper, we derive equations of motion for the normal-order, the symmetric-order and the antinormal-order quantum characteristic functions, applicable for general Hamiltonian systems. We do this by utilizing the `characteristic form'…

Quantum Physics · Physics 2008-05-02 Itay Hen , Amir Kalev

This work explores the behaviour of a noncommutative harmonic oscillator in a time-dependent background, as previously investigated in [1]. Specifically, we examine the system when expressed in terms of commutative variables, utilizing a…

Quantum Physics · Physics 2024-07-10 Manjari Dutta , Shreemoyee Ganguly , Sunandan Gangopadhyay

We explore whether quantum field theory can be understood as the statistical mechanics of a time-reversal-invariant stochastic generalization of Hamiltonian dynamics. The motivation for this project, started with this paper, is to assign…

Quantum Physics · Physics 2026-03-24 Simon Friederich , Mritunjay Tyagi

Quantum mechanics has been formulated in phase space, with the Wigner function as the representative of the quantum density operator, and classical mechanics has been formulated in Hilbert space, with the Groenewold operator as the…

Quantum Physics · Physics 2017-02-23 A. J. Bracken , J. G. Wood

An analytically derived 'integral operator' approach is introduced to estimate the expectation value of a quantum operator for an evolving state weighted with an exponential function. This allows to compute quantities useful in Nuclear…

Quantum Physics · Physics 2017-05-16 Simone Sturniolo

We show that the Schr\"{o}dinger equation for the quantum harmonic oscillator can be derived as an approximation to the Newtonian mechanics of a classical harmonic oscillator subject to a random force for time intervals $O( m / \hbar)$,…

Quantum Physics · Physics 2021-03-29 Can Gokler

The concept of out-of-time-ordered correlation (OTOC) function is treated as a very strong theoretical probe of quantum randomness, using which one can study both chaotic and non-chaotic phenomena in the context of quantum statistical…

The definition for the Slater-type orbitals is generalized. Transformation between an orthonormal basis function and the Slater-type orbital with non-integer principal quantum numbers is investigated. Analytical expressions for the linear…

Chemical Physics · Physics 2022-10-11 A. Bağcı , P. E. Hoggan

We study the classical and quantum theory of a class of nonlinear differential equations on chronology violating spacetime models in which space consists of finitely many discrete points. Classically, in the linear and weakly nonlinear…

General Relativity and Quantum Cosmology · Physics 2008-11-26 C. J. Fewster , A. Higuchi , C. G. Wells

A comparison of classical and quantum evolution usually involves a quasi-probability distribution as a quantum analogue of the classical phase space distribution. In an alternate approach that we adopt here, the classical density is…

Chaotic Dynamics · Physics 2009-11-10 Debabrata Biswas

We consider the quantisation of the Artin dynamical system defined on the fundamental region of the modular group. In classical regime the geodesic flow in the fundamental region represents one of the most chaotic dynamical systems, it has…

High Energy Physics - Theory · Physics 2019-10-15 Hrachya Babujian , Rubik Poghossian , George Savvidy

The quantum states representing classical phase space are given, and these are used to formulate quantum statistical mechanics as a formally exact double perturbation expansion about classical statistical mechanics. One series of quantum…

Quantum Physics · Physics 2016-11-03 Phil Attard

We establish weighted $L^p$-Fourier-extension estimates for $O(N-k) \times O(k)$-invariant functions defined on the unit sphere $\mathbb{S}^{N-1}$, allowing for exponents $p$ below the Stein-Tomas critical exponent $\frac{2(N+1)}{N-1}$.…

Analysis of PDEs · Mathematics 2021-01-20 Tobias Weth , Tolga Yesil

We derive an asymptotic expansion for off-diagonal coherent-state matrix elements of non-polynomial operators in gauge theories admitting holomorphic coherent-state representations. The derivation combines stationary-phase analysis with an…

General Relativity and Quantum Cosmology · Physics 2026-04-01 Haida Li , Hongguang Liu