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The space-time correlations of streams of photons can provide fundamentally new channels of information about the Universe. Today's astronomical observations essentially measure certain amplitude coherence functions produced by a source.…

Instrumentation and Methods for Astrophysics · Physics 2009-03-03 C. Barbieri , M. K. Daniel , W. J. de Wit , D. Dravins , H. Jensen , P. Kervella , S. Le Bohec , F. Malbet , P. Nunez , J. P. Ralston , E. N. Ribak

HI intensity mapping is a promising technique to probe large-scale structure, traditionally analyzed via two-point statistics such as the angular power spectrum. This technique has proven very powerful but may miss key non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Pauline Gorbatchev , Jean-Luc Starck , Stefano Camera , Marta Spinelli

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson

Phases of the spherical harmonic analysis of full-sky cosmic microwave background (CMB) temperature data contain useful information complementary to the ubiquitous angular power spectrum. In this letter we present a new method of phase…

Astrophysics · Physics 2009-11-16 Lung-Yih Chiang , Pavel D. Naselsky

Line-intensity mapping (IM) experiments seek to perform statistical measurements of large-scale structure with spectral lines such as 21cm, CO, and Lyman-$\alpha$ (Ly$\alpha$). A challenge in these observations is to ensure that…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-11 Eli Visbal , Matthew McQuinn

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 H. T. Intema , S. van der Tol , W. D. Cotton , A. S. Cohen , I. M. van Bemmel , H. J. A. Rottgering

We present a code to generate mock observations of 21 cm intensity mapping experiments. The emphasis of the code is on reducing the computational cost of running a full-blown simulation, trading computational time for accuracy. The code can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 David Alonso , Pedro G. Ferreira , Mario G. Santos

Neutral hydrogen (H$_{\rm I}$) intensity mapping is capable of measuring redshift evolution of H$_{\rm I}$ density parameter $\Omega_{\rm H_{\rm I}}$, which is an important parameter to understand structure formation in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-28 Shoichiro Tanaka , Shintaro Yoshiura , Kenji Kubota , Keitaro Takahashi , Atsushi J. Nishizawa , Naoshi Sugiyama

We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are…

Astrophysics · Physics 2009-11-13 F. A. Dahlen , Frederik J Simons

The anomaly against the Gaussianity in the WMAP data was alleged to be due to insufficient handling of beam asymmetries. In this paper we investigate this issue and develop a method to estimate the shape of the inflight effective beam,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Lung-Yih Chiang

When two bodies get into contact, only a small portion of the apparent area is actually involved in producing contact and friction forces, because of the surface roughnesses. It is therefore crucial to accurately describe the morphology of…

Numerical Analysis · Mathematics 2024-11-19 Mahmoud Shaqfa , Gary P. T. Choi , Guillaume Anciaux , Katrin Beyer

Spectral densities encode non-perturbative information that enters the calculation of a plethora of physical observables in strongly coupled field theories. Phenomenological applications encompass aspects of standard-model hadronic physics,…

Intensity interferometry removes the stringent requirements on mechanical precision and atmospheric corrections that plague all amplitude interferometry techniques at the cost of severely limited sensitivity. A new idea we recently…

Astrophysics · Physics 2009-11-11 Aviv Ofir , Erez N. Ribak

We explore the information content of 21cm intensity maps in redshift space using the 1-loop Effective Field Theory power spectrum model and the bispectrum at tree level. The 21cm signal contains signatures of dark matter, dark energy and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Liantsoa F. Randrianjanahary , Dionysios Karagiannis , Roy Maartens

This work concerns a detailed review of data analysis methods used for remotely sensed images of large areas of the Earth and of other solid astronomical objects. In detail, it focuses on the problem of inferring the materials that cover…

Instrumentation and Methods for Astrophysics · Physics 2025-07-22 Alfredo Gimenez Zapiola , Andrea Boselli , Alessandra Menafoglio , Simone Vantini

The three-dimensional galaxy power spectrum is a powerful probe of primordial non-Gaussianity and additional general relativistic effects, which become important on large scales. At the same time, wide-angle (WA) effects due to differing…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-29 Robin Y. Wen , Henry S. Grasshorn Gebhardt , Chen Heinrich , Olivier Doré

The presence of interharmonics in power systems can lead to asynchronous sampling, a phenomenon further aggravated by shifts in the fundamental frequency, which significantly degrades the accuracy of power measurements. Under such…

Signal Processing · Electrical Eng. & Systems 2026-01-30 Jian Liu , Wei Zhao , Jianting Zhao , Shisong Li

We have developed a fast, accurate and generally applicable method for inferring the power spectrum and its uncertainties from maps of the cosmic microwave background (CMB) in the presence of inhomogeneous and correlated noise. For maps…

Astrophysics · Physics 2014-10-13 O. Doré , L. Knox , A. Peel

We present a data-driven technique to analyze multifrequency images from upcoming cosmological surveys mapping large sky area. Using full information from the data at the two-point level, our method can simultaneously constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 Yun-Ting Cheng , Benjamin D. Wandelt , Tzu-Ching Chang , Olivier Dore

Intensity mapping of neutral hydrogen (HI) is a promising observational probe of cosmology and large-scale structure. We present wide field simulations of HI intensity maps based on N-body simulations of a $2.6\, {\rm Gpc / h}$ box with…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-02 Sebastian Seehars , Aseem Paranjape , Amadeus Witzemann , Alexandre Refregier , Adam Amara , Joel Akeret