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This paper studies linear reconstruction of partially observed functional data which are recorded on a discrete grid. We propose a novel estimation approach based on approximate factor models with increasing rank taking into account…

Statistics Theory · Mathematics 2024-05-22 Maximilian Ofner , Siegfried Hörmann

The currently used linear and nonlinear lens inversion techniques are based on distortion estimators whose complicated source redshift dependence makes the influence of the redshift distribution of the sources difficult to take into account…

Astrophysics · Physics 2007-05-23 Pierre-Yves Longaretti

In this paper, a modified factor $\mu$, which characterizes modified gravity in the linear matter density perturbation theory, is reconstructed in a data-driven and almost model-independent way via Gaussian process by using currently…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-12 Yuhao Mu , En-Kun Li , Lixin Xu

We study the accelerated expansion phase of the universe by using the {\textit{kinematic approach}}. In particular, the deceleration parameter $q$ is parametrized in a model-independent way. Considering a generalized parametrization for…

General Relativity and Quantum Cosmology · Physics 2018-10-22 Abdulla Al Mamon , Kazuharu Bamba

We consider the estimation of a structural function which models a non-parametric relationship between a response and an endogenous regressor given an instrument in presence of dependence in the data generating process. Assuming an…

Statistics Theory · Mathematics 2016-04-08 Nicolas Asin , Jan Johannes

The paper deals with the nonparametric estimation problem at a given fixed point for an autoregressive model with unknown distributed noise. Kernel estimate modifications are proposed. Asymptotic minimax and efficiency properties for…

Statistics Theory · Mathematics 2008-06-19 Ouerdia Arkoun , Serguei Pergamenchtchikov

Current cosmological observations allow for deviations from the standard growth of large-scale structures in the universe. These deviations could indicate modifications to General Relativity on cosmological scales or suggest the dynamical…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-12 Yo Toda , Adrià Gómez-Valent , Kazuya Koyama

We reexamine the kink-like parameterization of the deceleration parameter to derive constraints on the transition redshift from cosmic deceleration to acceleration. This is achieved using observational Hubble data, Type Ia Supernovae…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-30 Simran Arora , P. K. Sahoo

Reconstruction fidelity of sparse signals contaminated by sparse noise is considered. Statistical mechanics inspired tools are used to show that the l1-norm based convex optimization algorithm exhibits a phase transition between the…

Information Theory · Computer Science 2013-09-17 Mikko Vehkapera , Yoshiyuki Kabashima , Saikat Chatterjee

This paper is concerned with an inverse moving point source problem in electromagnetics. The aim is to reconstruct the moving orbit from the tangential components of magnetic fields taken at a finite number of observation points. The…

Numerical Analysis · Mathematics 2025-07-22 Minghui Li , Guanghui Hu , Yue Zhao

Constraining the dark energy deceleration parameter is one of the fascinating topics in the recent cosmological paradigm. This work aims to reconstruct the dark energy using parametrization of the deceleration parameter in a flat FRW…

General Relativity and Quantum Cosmology · Physics 2023-09-26 Amine Bouali , Himanshu Chaudhary , Ujjal Debnath , Alok Sardar , G. Mustafa

An expansion based on renormalization group methods for the spin correlation function in the z direction of the Heisenberg-Ising XYZ chain with an external magnetic field directed as the z axis is derived. Moreover, by using the hidden…

Statistical Mechanics · Physics 2007-05-23 G. Benfatto , V. Mastropietro

This letter announces and summarizes results obtained in arXiv:1111.5051 and considers several natural extensions. The aforementioned paper proposes a procedure to reconstruct coefficients in a second-order, scalar, elliptic equation from…

Analysis of PDEs · Mathematics 2012-03-07 Guillaume Bal , Gunther Uhlmann

We investigate the ability of state-of-the-art redshift-space distortions models for the galaxy anisotropic two-point correlation function \xi(r_p, \pi), to recover precise and unbiased estimates of the linear growth rate of structure f,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Sylvain de la Torre , Luigi Guzzo

Motivated by the study of reversal behaviour of myxobacteria, in this article we are interested in a kinetic model for reversal dynamics, in which particles with directions close to be opposite undergo binary collision resulting in…

Analysis of PDEs · Mathematics 2023-05-22 Amic Frouvelle , Laura Kanzler , Christian Schmeiser

The observed two-point correlation functions of galaxies in redshift space become anisotropic due to the geometry of the universe as well as due to the presence of the peculiar velocity field. On the basis of linear perturbation theory, we…

Astrophysics · Physics 2009-10-30 Takahiro T. Nakamura , Takahiko Matsubara , Yasushi Suto

Compressed sensing is triggering a major evolution in signal acquisition. It consists in sampling a sparse signal at low rate and later using computational power for its exact reconstruction, so that only the necessary information is…

Statistical Mechanics · Physics 2012-06-07 Florent Krzakala , Marc Mézard , François Sausset , Yifan Sun , Lenka Zdeborová

We derive some basic equations related to the redshift drift and we show how some dark energy (DE) properties can be retrieved from it. We consider in particular three kinds of DE models which exhibit a characteristic signature in their…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Bruno Moraes , David Polarski

In this paper, we expand the theory of depth-unbiased source localization to unbiased parameter estimation and signal reconstruction of an arbitrary number of non-zero parameters to be recovered. The topic touches on the concept of exact…

Information Theory · Computer Science 2026-05-08 Joonas Lahtinen

This paper proposes the capped least squares regression with an adaptive resistance parameter, hence the name, adaptive capped least squares regression. The key observation is, by taking the resistant parameter to be data dependent, the…

Methodology · Statistics 2021-07-02 Qiang Sun , Rui Mao , Wen-Xin Zhou