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Related papers: Spectral Simulation of Functional Time Series

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In this paper, we study nonparametric models allowing for locally stationary regressors and a regression function that changes smoothly over time. These models are a natural extension of time series models with time-varying coefficients. We…

Statistics Theory · Mathematics 2013-02-19 Michael Vogt

Despite the eminent successes of deep neural networks, many architectures are often hard to transfer to irregularly-sampled and asynchronous time series that commonly occur in real-world datasets, especially in healthcare applications. This…

Machine Learning · Computer Science 2020-09-16 Max Horn , Michael Moor , Christian Bock , Bastian Rieck , Karsten Borgwardt

In this study, we develop an asymptotic theory of nonparametric regression for a locally stationary functional time series. First, we introduce the notion of a locally stationary functional time series (LSFTS) that takes values in a…

Statistics Theory · Mathematics 2022-07-04 Daisuke Kurisu

We present Spectral Inference Networks, a framework for learning eigenfunctions of linear operators by stochastic optimization. Spectral Inference Networks generalize Slow Feature Analysis to generic symmetric operators, and are closely…

Machine Learning · Computer Science 2020-01-17 David Pfau , Stig Petersen , Ashish Agarwal , David G. T. Barrett , Kimberly L. Stachenfeld

This survey provides an overview of optimal estimation of linear functionals which depend on the unknown values of a stationary stochastic sequence. Based on observations of the sequence without noise as well as observations of the sequence…

Statistics Theory · Mathematics 2024-06-27 Mikhail Moklyachuk

In this paper, we propose a spectral method for deriving functions that are jointly smooth on multiple observed manifolds. This allows us to register measurements of the same phenomenon by heterogeneous sensors, and to reject…

Machine Learning · Computer Science 2022-04-15 Felix Dietrich , Or Yair , Rotem Mulayoff , Ronen Talmon , Ioannis G. Kevrekidis

Time-resolved spectroscopy is a powerful tool for probing electron dynamics in molecules and solids, revealing transient phenomena on sub-femtosecond timescales. The interpretation of experimental results is often enhanced by parallel…

Computational Physics · Physics 2025-05-02 Cian Reeves , Michael Kurniawan , Yuanran Zhu , Nikil Jampana , Jacob Brown , Chao Yang , Khaled Ibrahim , Vojtech Vlcek

These notes offer a unified introduction to spectral methods for the study of complex systems. They are intended as an operative manual rather than a theorem-proof textbook: the emphasis is on tools, identities, and perspectives that can be…

Statistical Mechanics · Physics 2025-09-10 Francesco Caravelli

We propose a general white noise test for functional time series based on estimating a distance between the spectral density operator of a weakly stationary time series and the constant spectral density operator of an uncorrelated time…

Statistics Theory · Mathematics 2020-07-07 Vaidotas Characiejus , Gregory Rice

Time series analysis is crucial in fields like finance, economics, environmental science, and biomedical engineering, aiding in forecasting, pattern identification, and understanding underlying mechanisms. While traditional time-domain…

Methodology · Statistics 2024-08-21 Jonathan de Souza Matias , Valderio Anselmo Reisen

We deal with the problem of optimal estimation of the linear functionals constructed from unobserved values of a continuous time stochastic process with periodically correlated increments based on past observations of this process. To solve…

Statistics Theory · Mathematics 2023-04-25 Maksym Luz , Mikhail Moklyachuk

We consider stochastic sequences with periodically stationary generalized multiple increments of fractional order which combines cyclostationary, multi-seasonal, integrated and fractionally integrated patterns. We solve the interpolation…

Statistics Theory · Mathematics 2025-11-11 Maksym Luz , Mykhailo Moklyachuk

Self-adjoint operators on infinite-dimensional spaces with continuous spectra are abundant but do not possess a basis of eigenfunctions. Rather, diagonalization is achieved through spectral measures. The SpecSolve package [SIAM Rev., 63(3)…

Numerical Analysis · Mathematics 2022-01-06 Matthew J. Colbrook , Andrew Horning

An accurate treatment of electronic spectra in large systems with a technique such as time dependent density functional theory (TDDFT) is computationally challenging. Due to the Nyquist sampling theorem, direct real time simulations must be…

Materials Science · Physics 2024-01-17 Matthias Kick , Ezra Alexander , Anton Beiersdorfer , Troy Van Voorhis

This paper introduces a spectral analysis of time-seires data derived from real-time time-dependent density functional theory (TDDFT) using Singular Spectrum Analysis (SSA). TDDFT is a robust method for obtaining molecular excited states…

Computational Physics · Physics 2025-10-02 Naoki Tani , Satoru S. Kano , Yasunari Zempo

We offer a spectral analysis for a class of transfer operators. These transfer operators arise for a wide range of stochastic processes, ranging from random walks on infinite graphs to the processes that govern signals and recursive wavelet…

Mathematical Physics · Physics 2018-02-14 Palle E. T. Jorgensen , Myung-Sin Song

Tests for structural breaks in time series should ideally be sensitive to breaks in the parameter of interest, while being robust to nuisance changes. Statistical analysis thus needs to allow for some form of nonstationarity under the null…

Methodology · Statistics 2022-12-02 Fabian Mies

The functional linear model extends the notion of linear regression to the case where the response and covariates are iid elements of an infinite dimensional Hilbert space. The unknown to be estimated is a Hilbert-Schmidt operator, whose…

Statistics Theory · Mathematics 2016-12-22 Tung Pham , Victor Panaretos

The aim of this article is to explore in all remaining aspects the spectral theory of locally normal operators. In a previous article we proved the spectral theorem in terms of locally spectral measures. Here we prove the spectral theorem…

Functional Analysis · Mathematics 2025-11-04 Aurelian Gheondea

The aim of this paper to give a multidimensional version of the classical one-dimensional case of smooth spectral density. A smooth spectral density gives an explicit method to factorize the spectral density and compute the constituents of…

Statistics Theory · Mathematics 2023-07-06 Tamás Szabados