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Related papers: Generalized Time-Varying Drude Model for Dispersiv…

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Space-time varying media enable unprecedented control over electromagnetic waves, yet most existing studies assume idealized, nondispersive materials and thus fail to capture the intrinsic frequency dispersion of realistic platforms. Here,…

Optics · Physics 2025-12-16 Klaas De Kinder , Christophe Caloz

Diffusion models have emerged as powerful generative frameworks by progressively adding noise to data through a forward process and then reversing this process to generate realistic samples. While these models have achieved strong…

Machine Learning · Computer Science 2025-03-04 Xingzhuo Guo , Yu Zhang , Baixu Chen , Haoran Xu , Jianmin Wang , Mingsheng Long

This letter introduces a formalism for modeling time-variant channels for diffusive molecular communication systems. In particular, we consider a fluid environment where one transmitter nano-machine and one receiver nano-machine are…

Information Theory · Computer Science 2017-03-08 Arman Ahmadzadeh , Vahid Jamali , Adam Noel , Robert Schober

Most of the existing diffusion models use Gaussian noise for training and sampling across all time steps, which may not optimally account for the frequency contents reconstructed by the denoising network. Despite the diverse applications of…

Computer Vision and Pattern Recognition · Computer Science 2024-05-03 Xingchang Huang , Corentin Salaün , Cristina Vasconcelos , Christian Theobalt , Cengiz Öztireli , Gurprit Singh

The time-frequency integrals and the two-dimensional stationary phase method are applied to study the electromagnetic waves radiated by moving modulated sources in dispersive media. We show that such unified approach leads to explicit…

Quantum Physics · Physics 2012-12-11 Gennadiy Burlak , Vladimir Rabinovich

Time-dependent density functional theory is extended to include dissipative systems evolving under a master equation, providing a Hamiltonian treatment for molecular electronics. For weak electric fields, the isothermal conductivity is…

Materials Science · Physics 2007-05-23 Kieron Burke , Roberto Car , Ralph Gebauer

Temporal modulation unlocks possibilities to dynamically control and modify the response of electromagnetic systems. Employing explicit dependencies of circuit or surface parameters on time enables the engineering of systems with…

Systems and Control · Electrical Eng. & Systems 2023-03-01 Grigorii Ptitcyn , Mohammad Sajjad Mirmoosa , Silvi Hrabar , Sergey Tretyakov

We study the motion of Brownian particle in modulated media in the strong damping limit by using {\em toy model}, with special emphasis on the transition from localise to diffusive behavior. By using model potential we have seen the…

Statistical Mechanics · Physics 2007-05-23 Himadri S. Samanta

We study, both theoretically and experimentally, the dynamical response of Turing patterns to a spatio-temporal forcing in the form of a travelling wave modulation of a control parameter. We show that from strictly spatial resonance, it is…

Chemical Physics · Physics 2009-11-10 S. Rudiger , D. G. Miguez , A. P. Munuzuri , F. Sagues , J. Casademunt

We show that in driven systems the Gaussian nature of the fluctuating force and time-reversibility are equivalent properties. This result together with the potential condition of the external force drastically restricts the form of the…

Statistical Mechanics · Physics 2007-06-11 M. H. Vainstein , J. M. Rubi

The Drude-Smith model successfully describes the frequency and phase-resolved electrical conductivity data for a surprisingly broad range of systems, especially in the terahertz region. Still, its interpretation is unclear since its…

Materials Science · Physics 2021-01-26 Keno L. Krewer , Marco Ballabio , Mischa Bonn

In coverage control problems that involve time-varying density functions, the coverage control law depends on spatial integrals of the time evolution of the density function. The latter is often neglected, replaced with an upper bound or…

Systems and Control · Electrical Eng. & Systems 2025-07-28 Behzad Zamani , James Kennedy , Airlie Chapman , Peter Dower , Chris Manzie , Simon Crase

We introduce a Langevin equation characterized by a time dependent drift. By assuming a temporal power-law dependence of the drift we show that a great variety of behavior is observed in the dynamics of the variance of the process. In…

Statistical Mechanics · Physics 2009-10-31 Fabrizio Lillo , Rosario N. Mantegna

We provide a theoretical framework to mold time-modulated lattices with frequency conversion and wave-steering capabilities. We initially focus on 1D lattices, whereby a sufficiently slow time-modulation of the stiffness is employed to…

Applied Physics · Physics 2023-02-15 Jonatha Santini , Emanuele Riva

In this paper the problems of the retrospective analysis of models with time-varying structure are considered. These models include contamination models with randomly switching parameters and multivariate classification models with an…

Statistics Theory · Mathematics 2017-10-31 Boris Brodsky , Boris Darkhovsky

Understanding and predicting environmental phenomena often requires the construction of spatio-temporal statistical models, which are typically Gaussian processes. A common assumption made on Gaussian processes is that of covariance…

Methodology · Statistics 2023-03-17 Quan Vu , Andrew Zammit-Mangion , Stephen J. Chuter

We investigate temporal scattering in lossless Drude media and reveal an overlooked role of the zero-frequency flat band associated with static polarization charge. This flat band forms an exceptional line spanning all wavenumbers and can…

Optics · Physics 2025-11-03 Neng Wang , Shuyong Chen , Guo Ping Wang

Time-varying photonic systems open new possibilities for controlling light, enabling photonic time crystals, time reflection and refraction, frequency conversion, synthetic gauge fields, optical nonreciprocity, among others. These effects…

Optics · Physics 2026-01-27 Zeki Hayran , John B. Pendry , Prasad P. Iyer , Francesco Monticone

The presence of a dispersed phase substantially modifies small-scale turbulence. However, there has not been a comprehensive mechanistically-based understanding to predict turbulence modulation. Based on the energy flux balance, we propose…

Fluid Dynamics · Physics 2023-11-23 S. Balachandar , C. Peng , L. -P. Wang

A diffusion-deposition model for glassy dynamics in compacting granular systems is treated by time scaling and by a method that provides the exact asymptotic (long time) behavior. The results include Vogel-Fulcher dependence of rates on…

Statistical Mechanics · Physics 2009-11-07 Robin Stinchcombe , Martin Depken