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This paper describes the implementation of the direct solution method (DSM) using radial spectral elements for the calculation of synthetic seismograms in self-gravitating, spherically symmetric, non-rotating, anelastic, and transversely…

Geophysics · Physics 2026-03-10 Alex D. C. Myhill , David Al-Attar

An estimation method is presented for polynomial phase signals, i.e., those adopting the form of a complex exponential whose phase is polynomial in its indices. Transcending the scope of existing techniques, the proposed estimator can…

Signal Processing · Electrical Eng. & Systems 2024-11-12 Heedong Do , Namyoon Lee , Angel Lozano

Direct detection of the Epoch of Reionization (EoR) via the red-shifted 21-cm line will have unprecedented implications on the study of structure formation in the infant Universe. To fulfill this promise, current and future 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Abhik Ghosh , Florent Mertens , Leon V. E. Koopmans

Analyses of stellar spectra often begin with the determination of a number of parameters that define a model atmosphere. This work presents a prototype for an automated spectral classification system that uses a 15 nm-wide region around…

Astrophysics · Physics 2016-08-30 C. Allende Prieto

The estimation of the signal location and intensity of a peak in a pulse height spectrum is important for x-ray and $\gamma$-ray spectroscopy, charged-particle spectrometry, liquid chromatography, and many other subfields. However, both the…

Data Analysis, Statistics and Probability · Physics 2021-03-03 Cade Rodgers , Christian Iliadis

The description of the inhomogeneity of the cosmic ray spectrum in the region of 10 TV, which is observed in experimental data, in terms of isotropic diffusion from a single close source is considered. It is shown that such a description is…

High Energy Astrophysical Phenomena · Physics 2021-09-20 I. Kudryashov , F. Gasratov , V. Yurovskiy , V. Latonov

In this article, we propose a spectral method for a class of multivariate inhomogeneous spatial point processes, namely the second-order intensity reweighted stationary processes. A key ingredient of our approach is utilizing the asymptotic…

Methodology · Statistics 2025-10-22 Qi-Wen Ding , Junho Yang , Joonho Shin

Over the last decade, measurements of the CMB anisotropy has spearheaded the remarkable transition of cosmology into a precision science. However, addressing the systematic effects in the increasingly sensitive, high resolution, `full' sky…

Astrophysics · Physics 2009-03-31 Sanjit Mitra , Anand S. Sengupta , Subharthi Ray , Rajib Saha , Tarun Souradeep

This paper generalises the hybrid power spectrum estimator developed in Efstathiou (2004a) to the estimation of polarization power spectra of the cosmic microwave background radiation. The hybrid power spectrum estimator is unbiased and we…

Astrophysics · Physics 2009-11-11 G. Efstathiou

A discrete spherical harmonics method is developed for the radiative transfer problem in inhomogeneous polarized planar atmosphere illuminated at the top by a collimated sunlight while the bottom reflects the radiation. The method expands…

Instrumentation and Methods for Astrophysics · Physics 2018-02-07 Romuald Tapimo , Hervé Thierry Tagne Kamdem , David Yemele

Nowadays, tens of satellites carry hyperspectral spectrometers. Such instruments allow decomposing the light that exits the atmosphere from its top into hundreds to thousands of contiguous spectral channels. By analysis of the light…

Instrumentation and Detectors · Physics 2025-04-29 Pierre Dussarrat , Guillaume Deschamps

We use an iterative generalized least squares map-making algorithm, in conjunction with Monte Carlo techniques, to obtain estimates of the angular power spectrum from cosmic microwave background (CMB) maps. This is achieved by…

Astrophysics · Physics 2009-11-07 A. Balbi , G. de Gasperis , P. Natoli , N. Vittorio

The angular power spectrum estimator developed by Peebles (1973) and Hauser & Peebles (1973) has been modified and applied to the 4 year maps produced by the COBE DMR. The power spectrum of the observed sky has been compared to the power…

Astrophysics · Physics 2008-11-26 E. L. Wright , C. L. Bennett , K. Gorski , G. Hinshaw , G. F. Smoot

In this article, we present a space-frequency theory for spherical harmonics based on the spectral decomposition of a particular space-frequency operator. The presented theory is closely linked to the theory of ultraspherical polynomials on…

Numerical Analysis · Mathematics 2013-07-16 Wolfgang Erb , Sonja Mathias

Spherical radial-basis-based kernel interpolation abounds in image sciences including geophysical image reconstruction, climate trends description and image rendering due to its excellent spatial localization property and perfect…

Machine Learning · Computer Science 2024-01-17 Xiaotong Liu , Jinxin Wang , Di Wang , Shao-Bo Lin

Obtaining the set of cosmological parameters consistent with observational data is an important exercise in current cosmological research. It involves finding the global maximum of the likelihood function in the multi-dimensional parameter…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-03 Jayanti Prasad , Tarun Souradeep

We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar Vacuum Tower Telescope on Tenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the…

Instrumentation and Methods for Astrophysics · Physics 2015-02-18 R A Probst , L Wang , H-P Doerr , T Steinmetz , T J Kentischer , G Zhao , T W Hänsch , Th Udem , R Holzwarth , W Schmidt

We describe a new algorithm for the "perfect" extraction of one-dimensional spectra from two-dimensional (2D) digital images of optical fiber spectrographs, based on accurate 2D forward modeling of the raw pixel data. The algorithm is…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Adam S. Bolton , David J. Schlegel

Multi-view data provides complementary information on the same set of observations, with multi-omics and multimodal sensor data being common examples. Analyzing such data typically requires distinguishing between shared (joint) and unique…

Machine Learning · Statistics 2025-08-14 Renat Sergazinov , Armeen Taeb , Irina Gaynanova

We present a method designed to estimate the noise power spectrum in the time domain for CMB experiments. The noise power spectrum is extracted from the time ordered data avoiding the contamination coming from sky signal and accounting the…

Astrophysics · Physics 2009-11-10 Alexandre Amblard , Jean-Christophe Hamilton