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We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

Astrophysics · Physics 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

Wavelets on the sphere are reintroduced and further developed independently of the original group theoretic formalism, in an equivalent, but more straightforward approach. These developments are motivated by the interest of the scale-space…

Astrophysics · Physics 2008-11-26 Y. Wiaux , L. Jacques , P. Vandergheynst

The cosmic microwave background (CMB) experiments have reached an era of unprecedented precision and complexity. Aiming to detect the primordial B-mode polarization signal, these experiments will soon be equipped with $10^{4}$ to $10^{5}$…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Avinash Anand , Giuseppe Puglisi

We study the gravitational radiation produced by the collisions of bubble walls or thin fluid shells in cosmological phase transitions. Using the so-called envelope approximation, we obtain analytically the asymptotic behavior of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Ariel Megevand , Agustin Membiela

A number of theoretically well-motivated additions to the standard cosmological model predict weak signatures in the form of spatially localized sources embedded in the cosmic microwave background (CMB) fluctuations. We present a…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-18 Stephen M. Feeney , Matthew C. Johnson , Jason D. McEwen , Daniel J. Mortlock , Hiranya V. Peiris

As new techniques exploiting the Earth's ambient seismic noise field are developed and applied, such as for the observation of temporal changes in seismic velocity structure, it is crucial to quantify the precision with which wave-type…

General Relativity and Quantum Cosmology · Physics 2019-11-28 M. Coughlin , J. Harms , D. C. Bowden , P. Meyers , V. C. Tsai , V. Mandic , G. Pavlis , T. Prestegard

Seismic imaging is the numerical process of creating a volumetric representation of the subsurface geological structures from elastic waves recorded at the surface of the Earth. As such, it is widely utilized in the energy and construction…

Geophysics · Physics 2024-11-05 Juan Romero , Wolfgang Heidrich , Nick Luiken , Matteo Ravasi

We investigate the properties of the (complex) coefficients obtained in a spherical harmonic representation of temperature maps of the cosmic microwave background (CMB). We study the effect of the coefficient phase only, as well as the…

Astrophysics · Physics 2009-11-10 Andrew Stannard , Peter Coles

This article describes the computation of cosmic microwave background anisotropies in a universe with multi-connected spatial sections and focuses on the implementation of the topology in standard CMB computer codes. The key ingredient is…

Astrophysics · Physics 2009-11-07 Alain Riazuelo , Jean-Philippe Uzan , Roland Lehoucq , Jeffrey Weeks

A flexible maximum-entropy component separation algorithm is presented that accommodates anisotropic noise, incomplete sky-coverage and uncertainties in the spectral parameters of foregrounds. The capabilities of the method are determined…

Polarized Galactic foregrounds are one of the primary sources of systematic error in measurements of the B-mode polarization of the Cosmic Microwave Background (CMB). Experiments are becoming increasingly sensitive to complexities in the…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-13 Brandon S. Hensley , Philip Bull

Ever since Cosmic Microwave Background (CMB) signal is being measured by various satellites based observations with increasing experimental accuracies there has been a parallel increase in the demand for a CMB reconstruction technique which…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-21 Ujjal Purkayastha , Vipin Sudevan , Rajib Saha

The cosmic microwave background (CMB) fluctuations effectively measure the basic properties of the universe during the recombination epoch. CMB measurements fix the distance to the surface of last scatter, the sound horizon of the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-02 Boryana Hadzhiyska , David N. Spergel

Seismic velocity is one of the most important parameters used in seismic exploration. Accurate velocity models are key prerequisites for reverse-time migration and other high-resolution seismic imaging techniques. Such velocity information…

Geophysics · Physics 2019-02-19 Fangshu Yang , Jianwei Ma

We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Lukas Hergt , Adam Amara , Robert Brandenberger , Tomasz Kacprzak , Alexandre Refregier

Circular polarization in the cosmic microwave background (CMB) offers a promising probe of the parity-violating physics of the early universe. In this paper, we propose a novel method to constrain the primordial circular polarization of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-24 Ashu Kushwaha , Rajeev Kumar Jain

Full-waveform inversion problems are usually formulated as optimization problems, where the forward-wave propagation operator $f$ maps the subsurface velocity structures to seismic signals. The existing computational methods for solving…

Signal Processing · Electrical Eng. & Systems 2020-01-07 Yue Wu , Youzuo Lin

A search for matched circle pairs of similar temperature fluctuations in the final WMAP 9yr data is carried out. Such a signature is expected if the space of the Universe is multiply connected. We investigate the relation between the pixel…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-22 Ralf Aurich , Sven Lustig

Coronal seismology is a diagnostic tool used in solar physics for measuring parameters that are otherwise hard to measure; of these parameters, magnetic field values are arguably the most important. The parameters are inferred by combining…

Solar and Stellar Astrophysics · Physics 2018-04-17 N. Magyar , T. Van Doorsselaere