English
Related papers

Related papers: Noise power spectrum estimation and fast map makin…

200 papers

Noise simulation is a very powerful tool in signal analysis helping to foresee the system performance in real experimental situations. Time series generation is however a hard challenge when a robust model of the noise sources is missing.…

Data Analysis, Statistics and Probability · Physics 2015-05-19 M. Carrettoni , O. Cremonesi

We present a new method to extract the beam shape incorporated in the pixelized map of CMB experiments. This method is based on the interplay of the amplitudes and phases of the signal and instrumental noise. By adding controlled white…

We use a convolutional neural network (CNN) to study cosmic string detection in cosmic microwave background (CMB) flat sky maps with Nambu-Goto strings. On noiseless maps we can measure string tensions down to order $10^{-9}$, however when…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-03 Razvan Ciuca , Oscar F. Hernández

A precise determination of the primordial spectrum of matter density fluctuations at super-horizon scales is essential in understanding large scale structure in the universe. Attempts to constrain or obtain the primordial spectrum using…

Astrophysics · Physics 2008-11-26 Rafael Bautista , Sergio Torres

We present a new Monte Carlo Markov Chain algorithm for CMB analysis in the low signal-to-noise regime. This method builds on and complements the previously described CMB Gibbs sampler, and effectively solves the low signal-to-noise…

Astrophysics · Physics 2011-02-11 J. B. Jewell , H. K. Eriksen , B. D. Wandelt , I. J. O'Dwyer , G. Huey , K. M. Gorski

We present a method for accelerating the calculation of CMB power spectra, matter power spectra and likelihood functions for use in cosmological parameter estimation. The algorithm, called CosmoNet, is based on training a multilayer…

Astrophysics · Physics 2008-11-26 T. Auld , M. Bridges , M. P. Hobson , S. F. Gull

We present a new method for fast computation of the realization-dependent bias, a major computational bottleneck in measurements of the cosmic microwave background (CMB) lensing power spectrum. The method accelerates the bias calculation by…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-19 Toshiya Namikawa , Blake D. Sherwin

We improve predictions of the cosmic microwave background (CMB) power spectrum induced by cosmic strings by using source terms obtained from Nambu-Goto network simulations in an expanding universe. We use three high-resolution cosmic string…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Andrei Lazanu , E. P. S. Shellard , Martin Landriau

We estimate CMB polarization and temperature power spectra using WMAP 5-year foreground contaminated maps. The power spectrum is estimated by using a model independent method, which does not utilize directly the diffuse foreground templates…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Pramoda Kumar Samal , Rajib Saha , Jacques Delabrouille , Simon Prunet , Pankaj Jain , Tarun Souradeep

CMB anisotropy experiments seeking to make maps with more pixels than the 6144 pixels used by the COBE DMR need to address the practical issues of the computer time and storage required to make maps. A simple, repetitive scan pattern…

Astrophysics · Physics 2007-05-23 Edward L. Wright

A great deal of experimental effort is currently being devoted to the precise measurements of the cosmic microwave background (CMB) sky in temperature and polarisation. Satellites, balloon-borne, and ground-based experiments scrutinize the…

Detection of B-mode polarization of the cosmic microwave background (CMB) radiation is one of the frontiers of observational cosmology. Because they are an order of magnitude fainter than E-modes, it is quite a challenge to detect B-modes.…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-23 Ata Karakci , P. M. Sutter , Le Zhang , Emory F. Bunn , Andrei Korotkov , Peter Timbie , Gregory S. Tucker , Benjamin D. Wandelt

We study different variants of the Gibbs sampler algorithm from the perspective of their applicability to the estimation of power spectra of the cosmic microwave background (CMB) anisotropies. These include approaches studied earlier in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-13 Gabriel Ducrocq , Nicolas Chopin , Josquin Errard , Radek Stompor

Primordial B-mode detection is one of the main goals of current and future cosmic microwave background (CMB) experiments. However, the weak B-mode signal is overshadowed by several Galactic polarized emissions, such as thermal dust emission…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-18 Ye-Peng Yan , Guo-Jian Wang , Si-Yu Li , Jun-Qing Xia

Component separation is the process with which emission sources in astrophysical maps are generally extracted by taking multi-frequency information into account. It is crucial to develop more reliable methods for component separation for…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-19 J. M. Casas , L. Bonavera , J. González-Nuevo , C. Baccigalupi , M. M. Cueli , D. Crespo , E. Goitia , J. D. Santos , M. L. Sánchez , F. J. de Cos

We present a new blind formulation of the Cosmic Microwave Background (CMB) inference problem. The approach relies on a phenomenological model of the multi-frequency microwave sky without the need for physical models of the individual…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-30 Flavien Vansyngel , Benjamin D. Wandelt , Jean-François Cardoso , Karim Benabed

We devise a fast and optimal estimator for the amplitude of the bispectrum of clustered Infrared (IR) point-sources. We show how this estimator can account for the cases of partial sky coverage and inhomogeneous noise. Expected detection…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 F. Lacasa , N. Aghanim

Fast robust methods for calculating likelihoods from CMB observations on small scales generally rely on approximations based on a set of power spectrum estimators and their covariances. We investigate the optimality of these approximation,…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Samira Hamimeche , Antony Lewis

We have compared the cosmic microwave background (CMB) temperature anisotropy maps made from one-year time ordered data (TOD) streams that simulated observations of the originally planned 100 GHz Planck Low Frequency Instrument (LFI). The…

We describe a sampling method to estimate the polarized CMB signal from observed maps of the sky. We use a Metropolis-within-Gibbs algorithm to estimate the polarized CMB map, containing Q and U Stokes parameters at each pixel, and its…

‹ Prev 1 4 5 6 7 8 10 Next ›