English
Related papers

Related papers: Dependent time changed processes with applications…

200 papers

This work discusses a variational approach to determining the time evolution operator. We directly see a glimpse of how a generalization of the quantum geometric tensor for unitary operators plays a central role in parameter evolution. We…

Quantum Physics · Physics 2025-04-15 Michael Vogl

We focus on variational inference in dynamical systems where the discrete time transition function (or evolution rule) is modelled by a Gaussian process. The dominant approach so far has been to use a factorised posterior distribution,…

Machine Learning · Statistics 2018-12-17 Alessandro Davide Ialongo , Mark van der Wilk , James Hensman , Carl Edward Rasmussen

We introduce an approach to scattering problems in theories with non-Hermitian Hamiltonian, usually known as PT-symmetric quantum theories, by means of the adiabatic switching of the interaction. The modifications of usual methods needed to…

Quantum Physics · Physics 2009-02-04 Hynek Bíla

We consider the case of a deformable material interface between two immiscible moving media, both of them being magnetiable. The time dependence of the metric at the interface introduces a non linear term, proportional to the mean…

Fluid Dynamics · Physics 2015-05-14 Q. Vanhaelen , M. Hennenberg , S. Slavtchev , B. Weyssow

Quantifying uncertainty in future climate projections is hindered by the prohibitive computational cost of running physical climate models, which severely limits the availability of training data. We propose a data-efficient framework for…

Methodology · Statistics 2026-02-27 Johannes Brachem , Paul F. V. Wiemann , Matthias Katzfuss

The Gaussian process is a powerful and flexible technique for interpolating spatiotemporal data, especially with its ability to capture complex trends and uncertainty from the input signal. This chapter describes Gaussian processes as an…

Machine Learning · Statistics 2021-10-11 Kien Nguyen , John Krumm , Cyrus Shahabi

It is no secret that statistical modelling often involves making simplifying assumptions when attempting to study complex stochastic phenomena. Spatial modelling of extreme values is no exception, with one of the most common such…

Applications · Statistics 2025-05-05 Lydia Kakampakou , Emma S. Simpson , Jennifer L. Wadsworth

Spatiotemporal dynamics models are fundamental for various domains, from heat propagation in materials to oceanic and atmospheric flows. However, currently available neural network-based spatiotemporal modeling approaches fall short when…

Machine Learning · Computer Science 2025-02-11 Valerii Iakovlev , Harri Lähdesmäki

Gaussian process is a theoretically appealing model for nonparametric analysis, but its computational cumbersomeness hinders its use in large scale and the existing reduced-rank solutions are usually heuristic. In this work, we propose a…

Machine Learning · Statistics 2015-11-25 Leo L. Duan , Xia Wang , Rhonda D. Szczesniak

The accuracy of Bayesian inference can be negatively affected by the use of inaccurate forward models. In the case of gravitational-wave inference, accurate but computationally expensive waveform models are sometimes substituted with faster…

Instrumentation and Methods for Astrophysics · Physics 2024-04-02 Miaoxin Liu , Xiao-Dong Li , Alvin J. K. Chua

An algorithm for determining stationary periods for time series of random sea waves is proposed in this work. This is a problem in which changes between stationary sea states are usually slow and segmentation procedures based on…

Methodology · Statistics 2015-06-22 Pedro C. Alvarez-Esteban , C. Euán , J. Ortega

This paper focuses on drawing inference on the causal impact of an intervention at a specific time point, as manifested in an outcome variable over time. We operate on the interrupted time series framework and expand on approaches such as…

Methodology · Statistics 2022-10-07 Gianluca Giudice , Sara Geneletti , Konstantinos Kalogeropoulos

An exact invariant is derived for $n$-degree-of-freedom Hamiltonian systems with general time-dependent potentials. The invariant is worked out in two equivalent ways. In the first approach, we define a special {\it Ansatz\/} for the…

Classical Physics · Physics 2023-03-23 Jürgen Struckmeier , Claus Riedel

Ocean motions at frequencies of the internal wave band are generally associated with freely propagating waves that are supported by stable vertical stratification in density. Previous analyses of yearlong current observations from the Bay…

Atmospheric and Oceanic Physics · Physics 2022-03-02 Hans van Haren , Leo Maas

A time-dependent global fiber-bundle model of fracture with continuous damage is formulated in terms of a set of coupled non-linear differential equations. A first integral of this set is analytically obtained. The time evolution of the…

Statistical Mechanics · Physics 2009-11-07 L. Moral , Y. Moreno , J. B. Gomez , A. F. Pacheco

This work proposes an algorithmic framework to learn time-varying graphs from online data. The generality offered by the framework renders it model-independent, i.e., it can be theoretically analyzed in its abstract formulation and then…

Machine Learning · Computer Science 2022-05-25 Alberto Natali , Elvin Isufi , Mario Coutino , Geert Leus

Systems where resource availability approaches a critical threshold are common to many engineering and scientific applications and often necessitate the estimation of first passage time statistics of a Brownian motion (Bm) driven by…

Statistical Mechanics · Physics 2011-04-05 Annalisa Molini , Peter Talkner , Gabriel G. Katul , Amilcare Porporato

In modelling time series data coming from different sources, frequencies can easily vary since some variable can be measured at higher frequencies, others, at lower frequencies. Given data measured over spatial units and at varying…

Methodology · Statistics 2025-03-05 Vladimir A. Malabanan , Joseph Ryan G. Lansangan , Erniel B. Barrios

An efficient algorithm for time propagation of the time-dependent Kohn-Sham equations is presented. The algorithm is based on dividing the Hamiltonian into small time steps and assuming that it is constant over these steps. This allows for…

Computational Physics · Physics 2014-12-03 J. K. Dewhurst , K. Krieger , S. Sharma , E. K. U. Gross

The Whitham equation is a nonlocal, nonlinear partial differential equation that models the temporal evolution of spatial profiles of surface displacement of water waves. However, many laboratory and field measurements record time series at…

Fluid Dynamics · Physics 2024-11-20 John D. Carter , Diane Henderson , Panayotis Panayotaros