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Current and upcoming large-scale structure surveys are pushing toward increasingly wide angular coverage, where wide-angle effects (arising from the varying line of sight across the curved sky) become critical for accurate modeling of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Robin Y. Wen , Henry S. Grasshorn Gebhardt , Chen Heinrich , Olivier Doré

With future galaxy surveys, a huge number of Fourier modes of the distribution of the large scale structures in the Universe will become available. These modes are complementary to those of the CMB and can be used to set constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Zhiqi Huang , Licia Verde , Filippo Vernizzi

Taking advantage of the smoothness of CMB Cl power spectra, we derive a simple and model-independent parameterization of their measurement. It allows to describe completely the spectrum, ie. provide an estimate of the value and the error…

Astrophysics · Physics 2007-05-23 S. Plaszczynski , F. Couchot

Recent analyses of the cosmic microwave background (CMB) maps from the WMAP satellite have uncovered evidence for a hemispherical power anomaly, i.e. a dipole modulation of the CMB power spectrum at large angular scales with an amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Christopher M. Hirata

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

We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Christopher Gauthier , Martin Bucher

The quantum mechanical harmonic oscillator Hamiltonian generates a one-parameter unitary group W(\theta) in L^2(R) which rotates the time-frequency plane. In particular, W(\pi/2) is the Fourier transform. When W(\theta) is applied to any…

Mathematical Physics · Physics 2009-11-07 Gerald Kaiser

Modern power systems are at risk of largely reducing the inertia of generation assets and prone to experience extreme dynamics. The consequence is that, during electromechanical transients triggered by large contingencies, transmission of…

Systems and Control · Electrical Eng. & Systems 2019-06-27 Asja Derviškadić , Guglielmo Frigo , Mario Paolone

In the era of high precision CMB measurements, systematic effects are beginning to limit the ability to extract subtler cosmological information. The non-circularity of the experimental beam has become progressively important as CMB…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Sanjit Mitra , Anand Sengupta , Subharthi Ray , Rajib Saha

Modeling power electronic converters at frequencies close to or above half the switching frequency has been difficult due to the time-variant and discontinuous switching actions. This paper uses the properties of moving Fourier coefficients…

Systems and Control · Electrical Eng. & Systems 2024-06-28 Hongchang Li , Kangping Wang , Jingyang Fang , Wenjie Chen , Xu Yang

Applying a transformation to a non-Gaussian field can enhance the information content of the resulting power spectrum, by reducing the correlations between Fourier modes. In the context of weak gravitational lensing, it has been shown that…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Fergus Simpson , Joachim Harnois-Déraps , Catherine Heymans , Raul Jimenez , Benjamin Joachimi , Licia Verde

We propose and develop a formalism to describe and constrain statistically anisotropic primordial perturbations. Starting from a decomposition of the primordial power spectrum in spherical harmonics, we find how the temperature fluctuations…

Astrophysics · Physics 2009-11-13 C. Armendariz-Picon

Graph signal processing (GSP) uses a shift operator to define a Fourier basis for the set of graph signals. The shift operator is often chosen to capture the graph topology. However, in many applications, the graph topology may be unknown a…

Signal Processing · Electrical Eng. & Systems 2023-03-30 Feng Ji , Wee Peng Tay , Antonio Ortega

We report a measurement of the quadrupole power spectrum in the two degree field (2dF) QSO redshift (2QZ) survey. The analysis uses an algorithm parallel to that for the estimation of the standard monopole power spectrum without first…

Weak gravitational lensing by intervening large-scale structure induces a distinct signature in the cosmic microwave background (CMB) that can be used to reconstruct the weak-lensing displacement map. Estimators for individual Fourier modes…

Astrophysics · Physics 2016-08-30 Michael Kesden , Asantha Cooray , Marc Kamionkowski

There has been a growing interest in wideband spectrum sensing due to its applications in cognitive radios and electronic surveillance. To overcome the sampling rate bottleneck for wideband spectrum sensing, in this paper, we study the…

Information Theory · Computer Science 2019-10-17 Linxiao Yang , Jun Fang , Huiping Duan , Hongbin Li

Radio interferometric data are used to estimate the sky brightness distributions in radio frequencies. Here we focus on estimators of the large-scale structure and the power spectrum of the sky brightness distribution inferred from radio…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Prasun Dutta , Meera Nandakumar

We use the projected clustering of quasars in the Gaia-unWISE quasar catalog, Quaia, and its cross-correlation with CMB lensing data from Planck, to measure the large-scale turnover of the matter power spectrum, associated with the size of…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 David Alonso , Oleksandr Hetmantsev , Giulio Fabbian , Anze Slosar , Kate Storey-Fisher

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark
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