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(Abridged) Estimating the uncertainty on the matter power spectrum internally (i.e. directly from the data) is made challenging by the simple fact that galaxy surveys offer at most a few independent samples. In addition, surveys have…

宇宙学与河外天体物理 · 物理学 2015-06-12 Joachim Harnois-Deraps , Ue-Li Pen

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

宇宙学与河外天体物理 · 物理学 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann

We present a Bayesian perspective on quantifying the uncertainty of graph signals estimated or reconstructed from imperfect observations. We show that many conventional methods of graph signal estimation, reconstruction and imputation, can…

信号处理 · 电气工程与系统科学 2025-05-22 Lennard Rompelberg , Michael T. Schaub

We present a novel method for generation of sets of the Cosmic Microwave Background (CMB) anisotropy maps, which reproduces the $\Delta \l=2$ correlations associated with Alfv\'en turbulence. The method is based on the non-linear…

天体物理学 · 物理学 2008-09-17 Pavel Naselsky , Jaiseung Kim

The Bayesian Conjugate Gradient method (BayesCG) is a probabilistic generalization of the Conjugate Gradient method (CG) for solving linear systems with real symmetric positive definite coefficient matrices. Our CG-based implementation of…

数值分析 · 数学 2022-10-04 Tim W. Reid , Ilse C. F. Ipsen , Jon Cockayne , Chris J. Oates

The map-making step of Cosmic Microwave Background data analysis involves linear inversion problems which cannot be performed by a brute force approach for the large timelines of today. We present in this article optimal vector-only…

天体物理学 · 物理学 2009-11-07 Xavier Dupac , Martin Giard

Gaussian time-series models are often specified through their spectral density. Such models present several computational challenges, in particular because of the non-sparse nature of the covariance matrix. We derive a fast approximation of…

统计计算 · 统计学 2012-11-20 Nicolas Chopin , Judith Rousseau , Brunero Liseo

Cosmic microwave background radiation (CMB) is critical to the understanding of the early universe and precise estimation of cosmological constants. Due to the contamination of thermal dust noise in the galaxy, the CMB map that is an image…

图像与视频处理 · 电气工程与系统科学 2020-02-03 Kai Yi , Yi Guo , Yanan Fan , Jan Hamann , Yu Guang Wang

Robust adaptive beamforming (RAB) based on interference-plus-noise covariance (INC) matrix reconstruction can experience performance degradation when model mismatch errors exist, particularly when the input signal-to-noise ratio (SNR) is…

信息论 · 计算机科学 2023-09-26 S. Mohammadzadeh , V. H. Nascimento , R. C. de Lamare , O. Kukrer

We study exact recovery for community detection in a Gaussian mixture model with dependent and heterogeneous Gaussian noise. The noise covariance matrix $\Sigma$ may be non-diagonal and, in the general formulation, singular. In the singular…

统计理论 · 数学 2026-05-05 Zhongyang Li , Sichen Yang

Background-Foreground classification is a well-studied problem in computer vision. Due to the pixel-wise nature of modeling and processing in the algorithm, it is usually difficult to satisfy real-time constraints. There is a trade-off…

机器学习 · 统计学 2019-11-19 B Ravi Kiran , Arindam Das , Senthil Yogamani

The Collective Graphical Model (CGM) models a population of independent and identically distributed individuals when only collective statistics (i.e., counts of individuals) are observed. Exact inference in CGMs is intractable, and previous…

机器学习 · 计算机科学 2014-05-21 Li-Ping Liu , Daniel Sheldon , Thomas G. Dietterich

We explore the possible application of linear covariance-based (LCB) filtering to line-intensity mapping (LIM) signal reconstructions. Originally introduced for reconstruction of the integrated Sachs-Wolfe effect in the cosmic microwave…

宇宙学与河外天体物理 · 物理学 2023-01-10 Dongwoo T Chung

Many problems arising in applications result in the need to probe a probability distribution for functions. Examples include Bayesian nonparametric statistics and conditioned diffusion processes. Standard MCMC algorithms typically become…

统计计算 · 统计学 2015-03-20 S. L. Cotter , G. O. Roberts , A. M. Stuart , D. White

We present the application of the Fast Independent Component Analysis ({\ica}) technique for blind component separation to polarized astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarized signal, consisting of…

天体物理学 · 物理学 2009-06-16 C. Baccigalupi , F. Perrotta , G. De Zotti , G. F. Smoot , C. Burigana , D. Maino , L. Bedini , E. Salerno

We develop two methods for estimating the power spectrum, C_l, of the cosmic microwave background (CMB) from data and apply them to the COBE/DMR and Saskatoon datasets. One method involves a direct evaluation of the likelihood function, and…

天体物理学 · 物理学 2009-10-30 J. R. Bond , A. H. Jaffe , L. Knox

We formulate a physics-informed compressed sensing (PICS) method for the reconstruction of velocity fields from noisy and sparse phase-contrast magnetic resonance signals. The method solves an inverse Navier-Stokes boundary value problem,…

计算机视觉与模式识别 · 计算机科学 2023-01-04 Alexandros Kontogiannis , Matthew P. Juniper

I show how a renormalization group (RG) method can be used to incrementally integrate the information in cosmological large-scale structure data sets (including CMB, galaxy redshift surveys, etc.). I show numerical tests for Gaussian…

宇宙学与河外天体物理 · 物理学 2019-03-06 Patrick McDonald

This paper concerns the Bayesian approach to inverse acoustic scattering problems of inferring the position and shape of a sound-soft obstacle from phaseless far-field data generated by point source waves. To improve the convergence rate,…

数值分析 · 数学 2021-08-23 Zhipeng Yang , Xinping Gui , Ju Ming , Guanghui Hu

Introducing inequality constraints in Gaussian process (GP) models can lead to more realistic uncertainties in learning a great variety of real-world problems. We consider the finite-dimensional Gaussian approach from Maatouk and Bay (2017)…

机器学习 · 统计学 2021-11-04 Andrés F. López-Lopera , François Bachoc , Nicolas Durrande , Olivier Roustant