English
Related papers

Related papers: Conformally covariant parameterizations for relati…

200 papers

The standard geometrodynamics is transformed into a theory of conformal geometrodynamics by extending the ADM phase space for canonical general relativity to that consisting of York's mean exterior curvature time, conformal three-metric and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles H. -T. Wang

A promising step from linear towards nonlinear data-driven control is via the design of controllers for linear parameter-varying (LPV) systems, which are linear systems whose parameters are varying along a measurable scheduling signal.…

Systems and Control · Electrical Eng. & Systems 2025-07-01 Chris Verhoek , Jaap Eising , Florian Dörfler , Roland Tóth

The Loewner equation, in its stochastic incarnation introduced by Schramm, is an insightful method for the description of critical random curves and interfaces in two-dimensional statistical mechanics. Two features are crucial, namely…

Statistical Mechanics · Physics 2015-06-16 Marco Gherardi , Alessandro Nigro

This paper focuses on representing the $L^{\infty}$-norm of finite-dimensional linear time-invariant systems with parameter-dependent coefficients. Previous studies tackled the problem in a non-parametric scenario by simplifying it to…

Symbolic Computation · Computer Science 2023-12-05 Alban Quadrat , Fabrice Rouillier , Grace Younes

Background: It has long been advised to account for baseline covariates in the analysis of confirmatory randomised trials, with the main statistical justifications being that this increases power and, when a randomisation scheme balanced…

Methodology · Statistics 2021-12-09 Tim P. Morris , A. Sarah Walker , Elizabeth J. Williamson , Ian R. White

Two adaptive bandwidth selection methods for nonparametric estimators in locally stationary processes are proposed. We investigate a cross validation approach and a method based on contrast minimization and derive asymptotic properties of…

Statistics Theory · Mathematics 2019-02-28 Rainer Dahlhaus , Stefan Richter

The L-curve method is a well-known heuristic method for choosing the regularization parameter for ill-posed problems by selecting it according to the maximal curvature of the L-curve. In this article, we propose a simplified version that…

Numerical Analysis · Mathematics 2021-04-14 Stefan Kindermann , Kemal Raik

Covariate-adaptive randomization (CAR) procedures are frequently used in comparative studies to increase the covariate balance across treatment groups. However, because randomization inevitably uses the covariate information when forming…

Statistics Theory · Mathematics 2022-07-08 Wei Ma , Yichen Qin , Yang Li , Feifang Hu

Compositional data have two unique characteristics compared to typical multivariate data: the observed values are nonnegative and their summand is exactly one. To reflect these characteristics, a specific regularized regression model with…

Machine Learning · Computer Science 2018-12-24 Jong-June Jeon , Yongdai Kim , Sungho Won , Hosik Choi

Covariant Lyapunov vectors characterize the directions along which perturbations in dynamical systems grow. They have also been studied as predictors of critical transitions and extreme events. For many applications like, for example,…

Data Analysis, Statistics and Probability · Physics 2022-03-14 Christoph Martin , Nahal Sharafi , Sarah Hallerberg

We propose a covariant algorithm for relativistic ideal measurements and for relativistic continuous measurements, its non-relativistic limit results the algorithm of the Event-Enhanced Quantum Theory. Therefore an additional intrinsic…

Quantum Physics · Physics 2007-05-23 Andreas Ruschhaupt

We introduce a new tool for the quantitative characterisation of the departure form Markovianity of a given dynamical process. Our tool can be applied to a generic $N$-level system and extended straightforwardly to Gaussian…

Quantum Physics · Physics 2015-06-15 S. Lorenzo , F. Plastina , M. Paternostro

Complex systems are sometimes subject to non Gaussian alpha stable Levy fluctuations. A new method is devised to estimate this uncertain parameter and other system parameters, using observations on either mean exit time or escape…

Dynamical Systems · Mathematics 2013-06-04 Ting Gao , Jinqiao Duan

We propose generalized additive partial linear models for complex data which allow one to capture nonlinear patterns of some covariates, in the presence of linear components. The proposed method improves estimation efficiency and increases…

Statistics Theory · Mathematics 2014-05-26 Li Wang , Lan Xue , Annie Qu , Hua Liang

Estimating the parameters of nonlinear block-oriented state-space models from input-output data typically involves solving a highly non-convex optimization problem, which is prone to poor local minima and slow convergence. This paper…

Systems and Control · Electrical Eng. & Systems 2025-07-08 Merijn Floren , Jean-Philippe Noël , Jan Swevers

Multi-wave inverse problems are indirect imaging methods using the interaction of two different imaging modalities. One brings spatial accuracy, and the other contrast sensitivity. The inversion method typically involve two steps. The first…

Analysis of PDEs · Mathematics 2023-01-05 Yves Capdeboscq , Tianrui Dai

A new parameter choice rule for inverse problems is introduced. This parameter choice rule was developed for total variation regularization in electron tomography and might in general be useful for $L^1$ regularization of inverse problems…

Numerical Analysis · Mathematics 2008-04-28 Hans Rullgård

The various phase spaces involved in the dynamics of parametrized nonrelativistic Hamiltonian systems are displayed by using Crnkovic and Witten's covariant canonical formalism. It is also pointed out that in Dirac's canonical formalism…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mauricio Mondragon , Merced Montesinos

We consider the linear and quadratic higher order terms associated to the response of the statistical properties of a dynamical system to suitable small perturbations. These terms are related to the first and second derivative of the…

Dynamical Systems · Mathematics 2020-02-12 Stefano Galatolo , Julien Sedro

Lancaster (2002} proposes an estimator for the dynamic panel data model with homoskedastic errors and zero initial conditions. In this paper, we show this estimator is invariant to orthogonal transformations, but is inefficient because it…

Methodology · Statistics 2017-02-09 Jose Diogo Barbosa , Marcelo J. Moreira