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We study the spread of a quantum-mechanical wavepacket in a noisy environment, modeled using a tight-binding Hamiltonian. Despite the coherent dynamics, the fluctuating environment may give rise to diffusive behavior. When correlations…

Statistical Mechanics · Physics 2019-07-29 Nisarga Paul , Ariel Amir

We study a generalization of the classical discrete-time, Linear-Quadratic-Gaussian (LQG) control problem where the noise distributions affecting the states and observations are unknown and chosen adversarially from divergence-based…

Optimization and Control · Mathematics 2025-09-30 Bahar Taşkesen , Dan A. Iancu , Çağıl Koçyiğit , Daniel Kuhn

Diffusion models have achieved remarkable success in generating samples from unknown data distributions. Most popular stochastic differential equation-based diffusion models perturb the target distribution by adding Gaussian noise,…

Machine Learning · Statistics 2026-05-20 Wenpin Tang , Nizar Touzi , Zikun Zhang , Xun Yu Zhou

A large deviation principle is established for a two-scale stochastic system in which the slow component is a continuous process given by a small noise finite dimensional It\^{o} stochastic differential equation, and the fast component is a…

Probability · Mathematics 2017-05-09 Amarjit Budhiraja , Paul Dupuis , Arnab Ganguly

We study a fairly general class of time-homogeneous stochastic evolutions driven by noises that are not white in time. As a consequence, the resulting processes do not have the Markov property. In this setting, we obtain constructive…

Probability · Mathematics 2009-02-12 M. Hairer

Gaussian quantum Markov semigroups are the natural non-commutative extension of classical Ornstein-Uhlenbeck semigroups. They arise in open quantum systems of bosons where canonical non-commuting random variables of positions and momenta…

Functional Analysis · Mathematics 2024-05-09 Franco Fagnola , Damiano Poletti , Emanuela Sasso , Veronica Umanità

Diffusion Models (DMs) are powerful generative models that add Gaussian noise to the data and learn to remove it. We wanted to determine which noise distribution (Gaussian or non-Gaussian) led to better generated data in DMs. Since DMs do…

Machine Learning · Computer Science 2023-04-13 Alexia Jolicoeur-Martineau , Kilian Fatras , Ke Li , Tal Kachman

We present a model for conductivity and energy diffusion in a linear chain described by a quadratic Hamiltonian with Gaussian noise. We show that when the correlation matrix is diagonal, the noise-averaged Liouville-von Neumann equation…

Statistical Mechanics · Physics 2009-11-11 Andrey Pereverzev , Eric R. Bittner

We put forward a measure based on Gaussian steering to quantify the non-Markovianity of continuous-variable (CV) Gaussian quantum channels. We employ the proposed measure to assess and compare the non-Markovianity of a quantum Brownian…

Quantum Physics · Physics 2021-11-17 Massimo Frigerio , Samaneh Hesabi , Davood Afshar , Matteo G. A. Paris

We analyse the problem of estimating a scalar parameter $g$ that controls the Hamiltonian of a quantum system subject to Markovian noise. Specifically, we place bounds on the growth rate of the quantum Fisher information with respect to…

Quantum Physics · Physics 2022-08-11 Kianna Wan , Robert Lasenby

We propose a novel method for drift estimation of multiscale diffusion processes when a sequence of discrete observations is given. For the Langevin dynamics in a two-scale potential, our approach relies on the eigenvalues and the…

Numerical Analysis · Mathematics 2022-04-15 Assyr Abdulle , Grigorios A. Pavliotis , Andrea Zanoni

We analyze the large-time asymptotics of a passive tracer with drift equal to the curl of the Gaussian free field in two dimensions with ultra-violet cut-off at scale unity. We prove that the mean-squared displacement scales like $t…

Probability · Mathematics 2025-11-24 Georgiana Chatzigeorgiou , Peter Morfe , Felix Otto , Lihan Wang

Precise qubit control in the presence of spatio-temporally correlated noise is pivotal for transitioning to fault-tolerant quantum computing. Generically, such noise can also have non-Gaussian statistics, which hampers existing…

Quantum Physics · Physics 2025-06-17 Wenzheng Dong , Yuanlong Wang , Muhammad Qasim Khan

Exceptional points (EPs), indicative of parity-time (PT) symmetry breaking, play a central role in non-Hermitian physics, yet most studies begin from deliberately engineered effective Hamiltonians whose parameters are tuned to exhibit…

Quantum Physics · Physics 2026-03-12 Eric R. Bittner , Bhavay Tyagi , Kevin E. Bassler

We investigate the universal dissipationless dynamics of Gaussian continuous-variable systems in the presence of a band-gapped bosonic environment. Our results show that environmental band gaps can induce localized modes, which give rise to…

Quantum Physics · Physics 2018-12-05 Han-Jie Zhu , Guo-Feng Zhang , Lin Zhuang , Wu-Ming Liu

In this work, we are concerned with existence and uniqueness of invariant measures for path-dependent random diffusions and their time discretizations. The random diffusion here means a diffusion process living in a random environment…

Probability · Mathematics 2017-06-20 Jianhai Bao , Jinghai Shao , Chenggui Yuan

Diffusion models are powerful deep generative models, but unlike classical models, they lack an explicit low-dimensional latent space that parameterizes the data manifold. This absence makes it difficult to perform manifold-aware…

Computer Vision and Pattern Recognition · Computer Science 2026-04-03 Shinnosuke Saito , Takashi Matsubara

We study a model of a quantum collective spin weakly coupled to a spin-polarized Markovian environment and find that the spectrum is divided into two regions that we name normal and exceptional Liouvillian spectral phases. In the…

In this note, we give a new proof of Liggett's theorem on the invariant measures of independent particle systems from [Lig78] in the particular case of independent drifted Brownian motions. This particular case has received a lot of…

Probability · Mathematics 2020-12-08 Xinxin Chen , Christophe Garban , Atul Shekhar

We present a channel-constrained Markovian quantum diffusion (CCMQD) model that prepares quantum states by rigorously framing the generative process within the dynamics of open quantum systems. Our model interprets the forward diffusion…

Quantum Physics · Physics 2025-11-18 Qin-Sheng Zhu , Geng Chen , Lian-Hui Yu , Xiaodong Xing , Xiao-Yu Li