Corrigendum to “Parity in Planck full-mission CMB temperature maps” [Astroparticle Physics, Vol. 125 (2021), 102493]

2021 ◽  
Vol 130 ◽  
pp. 102582
Author(s):  
Srikanta Panda ◽  
Pavan K. Aluri ◽  
Pramoda Kumar Samal ◽  
Pranati K. Rath
Keyword(s):  
Astroparticle Physics ◽  
Temperature Maps ◽  
Cmb Temperature

scholarly journals A convolutional neural network for cosmic string detection in CMB temperature maps

2019 ◽  
Vol 485 (1) ◽  
pp. 1377-1383 ◽  
Author(s):  
Razvan Ciuca ◽  
Oscar F Hernández ◽  
Michael Wolman
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Cosmic String ◽  
Temperature Maps ◽  
Cmb Temperature

scholarly journals Lensing-induced morphology changes in CMB temperature maps in modified gravity theories

2016 ◽  
Vol 2016 (04) ◽  
pp. 056-056 ◽  
Author(s):  
D. Munshi ◽  
B. Hu ◽  
T. Matsubara ◽  
P. Coles ◽  
A. Heavens
Keyword(s):  
Modified Gravity ◽  
Modified Gravity Theories ◽  
Gravity Theories ◽  
Temperature Maps ◽  
Morphology Changes ◽  
Cmb Temperature

scholarly journals Investigating non-Gaussianity in Cosmic Microwave Background temperature maps using spherical harmonic phases

2022 ◽  
Vol 2022 (01) ◽  
pp. 001
Author(s):  
Sarvesh Kumar Yadav ◽  
Rajib Saha
Keyword(s):  
Cosmic Microwave Background ◽  
Spherical Harmonic ◽  
Gaussian Random Field ◽  
Random Sets ◽  
Accurate Estimation ◽  
Implicit Assumption ◽  
Microwave Background ◽  
Non Gaussian ◽  
Temperature Maps ◽  
Cmb Temperature

Abstract In the era of precision cosmology, accurate estimation of cosmological parameters is based upon the implicit assumption of the Gaussian nature of Cosmic Microwave Background (CMB) radiation. Therefore, an important scientific question to ask is whether the observed CMB map is consistent with Gaussian prediction. In this work, we extend previous studies based on CMB spherical harmonic phases (SHP) to examine the validity of the hypothesis that the temperature field of the CMB is consistent with a Gaussian random field (GRF). The null hypothesis is that the corresponding CMB SHP are independent and identically distributed in terms of a uniform distribution in the interval [0, 2π] [1,2]. We devise a new model-independent method where we use ordered and non-parametric Rao's statistic, based on sample arc-lengths to comprehensively test uniformity and independence of SHP for a given ℓ mode and independence of nearby ℓ mode SHP. We performed our analysis on the scales limited by spherical harmonic modes ≤ 128, to restrict ourselves to signal-dominated regions. To find the non-uniform or dependent sets of SHP, we calculate the statistic for the data and 10000 Monte Carlo simulated uniformly random sets of SHP and use 0.05 and 0.001 α levels to distinguish between statistically significant and highly significant detections. We first establish the performance of our method using simulated Gaussian, non-Gaussian CMB temperature maps, along with observed non-Gaussian 100 and 143 GHz Planck channel maps. We find that our method, performs efficiently and accurately in detecting phase correlations generated in all of the non-Gaussian simulations and observed foreground contaminated 100 and 143 GHz Planck channel temperature maps. We apply our method on Planck satellite mission's final released CMB temperature anisotropy maps- COMMANDER, SMICA, NILC, and SEVEM along with WMAP 9 year released ILC map. We report that SHP corresponding to some of the m-modes are non-uniform, some of the ℓ mode SHP and neighboring mode pair SHP are correlated in cleaned CMB maps. The detection of non-uniformity or correlation in the SHP indicates the presence of non-Gaussian signals in the foreground minimized CMB maps.

scholarly journals Parity in Planck full-mission CMB temperature maps

2021 ◽  
Vol 125 ◽  
pp. 102493
Author(s):  
Srikanta Panda ◽  
Pavan K. Aluri ◽  
Pramoda Kumar Samal ◽  
Pranati K. Rath
Keyword(s):  
Temperature Maps ◽  
Cmb Temperature

A new probe of Gaussianity and isotropy with application to cosmic microwave background maps

2021 ◽  
pp. 2150084
Author(s):  
J. Hamann ◽  
Q. T. Le Gia ◽  
I. H. Sloan ◽  
Y. G. Wang ◽  
R. S. Womersley
Keyword(s):  
Cosmic Microwave Background ◽  
Random Fields ◽  
Fourier Coefficients ◽  
Galactic Plane ◽  
Gaussian Random Fields ◽  
Mathematical Tool ◽  
Microwave Background ◽  
Temperature Maps ◽  
Cmb Temperature ◽  
Dependent Probe

We introduce a new mathematical tool (a direction-dependent probe) to analyze the randomness of purported isotropic Gaussian random fields on the sphere. If the field is isotropic and Gaussian then the probe coefficients for a given direction should be realizations of uncorrelated scalar Gaussian random variables. To study the randomness of a field, we use the autocorrelation of the sequence of probe coefficients (which are just the Fourier coefficients [Formula: see text] if the [Formula: see text]-axis is taken in the probe direction). We introduce a particular function on the sphere (called the AC discrepancy) that accentuates the departure from Gaussianity and isotropy. We apply the probe to assess the full-sky cosmic microwave background (CMB) temperature maps produced by the Planck collaboration (PR2 2015 and PR3 2018), with special attention to the inpainted maps. We find that for some of the maps, there are many directions for which the departures are significant, especially near the galactic plane. We also look briefly at the noninpainted Planck maps, for which the computed AC discrepancy maps have a very different character, with features that are global rather than local.

scholarly journals Foreground removal from CMB temperature maps using an MLP neural network

2008 ◽  
Vol 318 (3-4) ◽  
pp. 195-206 ◽  
Author(s):  
H. U. Nørgaard-Nielsen ◽  
H. E. Jørgensen
Keyword(s):  
Neural Network ◽  
Mlp Neural Network ◽  
Temperature Maps ◽  
Foreground Removal ◽  
Cmb Temperature

Subsurface imaging for panel paintings inspection: A comparative study of the ultraviolet, the visible, the infrared and the terahertz spectra

2015 ◽  
Vol 23 (1) ◽  
Author(s):  
A. Bendada ◽  
S. Sfarra ◽  
C. Ibarra−Castanedo ◽  
M. Akhloufi ◽  
J.−P. Caumes ◽  
...  
Keyword(s):  
Subsurface Imaging ◽  
Wide Spread ◽  
Ir Thermography ◽  
Complementary Information ◽  
Ir Sensors ◽  
The World ◽  
Panel Paintings ◽  
Temperature Maps ◽  
Illumination Source ◽  
Ir Reflectography

AbstractInfrared (IR) reflectography has been used for many years for the detection of underdrawings on panel paintings. Advances in the fields of IR sensors and optics have impelled the wide spread use of IR reflectography by several recognized Art Museums and specialized laboratories around the World. The transparency or opacity of a painting is the result of a complex combination of the optical properties of the painting pigments and the underdrawing material, as well as the type of illumination source and the sensor characteristics. For this reason, recent researches have been directed towards the study of multispectral approaches that could provide simultaneous and complementary information of an artwork. The present work relies on non−simultaneous multispectral inspection using a set of detectors covering from the ultraviolet to the terahertz spectra. It is observed that underdrawings contrast increases with wavelength up to 1700 nm and, then, gradually decreases. In addition, it is shown that IR thermography, i.e., temperature maps or thermograms, could be used simultaneously as an alternative technique for the detection of underdrawings besides the detection of subsurface defects.

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