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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

The cosmic microwave background (CMB) is a significant source of knowledge about the origin and evolution of our universe. However, observations of the CMB are contaminated by foreground emissions, obscuring the CMB signal and reducing its…

Machine Learning · Computer Science 2023-02-27 Jadie Adams , Steven Lu , Krzysztof M. Gorski , Graca Rocha , Kiri L. Wagstaff

One of the main obstacles for extracting the Cosmic Microwave Background (CMB) from mm/submm observations is the pollution from the main Galactic components: synchrotron, free-free and thermal dust emission. The feasibility of using simple…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 H. U. Nørgaard-Nielsen

Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy…

Astrophysics · Physics 2010-04-15 Levon Pogosian , S. -H. Henry Tye , Ira Wasserman , Mark Wyman

Semantic segmentation is an established while rapidly evolving field in medical imaging. In this paper we focus on the segmentation of brain Magnetic Resonance Images (MRI) into cerebral structures using convolutional neural networks (CNN).…

Computer Vision and Pattern Recognition · Computer Science 2018-04-13 Pierre-Antoine Ganaye , Michaël Sdika , Hugues Benoit-Cattin

We calculate the cosmic microwave background (CMB) $B$-mode power spectrum resulting from anisotropic cosmic birefringence, without relying on the thin approximation of the last scattering surface. Specifically, we consider the influence of…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-04 Toshiya Namikawa

We study the observational constraints for the axion models in string theory which can successfully act as quintessence. The evolution of the universe in this model is sensitive to the initial value of the axion field. This initial value of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Gaveshna Gupta , Sudhakar Panda , Anjan A Sen

Parity-violating extensions of Maxwell electromagnetism induce a rotation of the linear polarization plane of photons during propagation. This effect, known as cosmic birefringence, impacts on the Cosmic Microwave Background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 Alessandro Greco , Nicola Bartolo , Alessandro Gruppuso

Weak Lensing (WL) surveys are reaching unprecedented depths, enabling the investigation of very small angular scales. At these scales, nonlinear gravitational effects lead to higher-order correlations making the matter distribution highly…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-01 Divij Sharma , Biwei Dai , Uros Seljak

Recently, based on a novel analysis of the Planck satellite data, a hint of a uniform rotation of the polarization of cosmic microwave background photons, called isotropic cosmic birefringence, has been reported. The suggested rotation…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Naoya Kitajima , Fumiaki Kozai , Fuminobu Takahashi , Wen Yin

This work investigates use of equivariant neural networks as efficient and high-performance frameworks for image reconstruction and denoising in nuclear medicine. Our work aims to tackle limitations of conventional Convolutional Neural…

Image and Video Processing · Electrical Eng. & Systems 2025-02-03 Amirreza Hashemi , Yuemeng Feng , Arman Rahmim , Hamid Sabet

Making use of the wealth of new observational data coming from the sky it is possible to constrain particle physics theories beyond the Standard Model. One way to do this is illustrated in this article: a subset of theories admits cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-21 Robert H. Brandenberger

We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Nicoletta Krachmalnicoff , Maurizio Tomasi

We present a neural net algorithm for parameter estimation in the context of large cosmological data sets. Cosmological data sets present a particular challenge to pattern-recognition algorithms since the input patterns (galaxy redshift…

Astrophysics · Physics 2007-05-23 Nicholas G. Phillips , A. Kogut

Very light pseudoscalar fields, often referred to as axions, are compelling dark matter candidates and can potentially be detected through their coupling to the electromagnetic field. Recently a novel detection technique using the cosmic…

If they exist, networks of superconducting cosmic strings are capable of injecting copious amounts of electromagnetic energy into the background over a broad range of frequencies. We study this injection both analytically, as well as…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-18 Bryce Cyr , Jens Chluba , Sandeep Kumar Acharya

An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian…

Astrophysics · Physics 2009-11-16 D. K. Hammond , Y. Wiaux , P. Vandergheynst

We present a neural net algorithm for parameter estimation in the context of large cosmological data sets. Cosmological data sets present a particular challenge to pattern-recognition algorithms since the input patterns (galaxy redshift…

Astrophysics · Physics 2007-05-23 Nicholas G. Phillips , A. Kogut

Cosmic strings formed when the Peccei-Quinn symmetry breaks post-inflation are expected to emit axions throughout their lifetime. The details of the evolution of this network and the associated spectrum of axions are crucial for obtaining…

High Energy Physics - Phenomenology · Physics 2025-12-16 José Correia , Mark Hindmarsh , Joanes Lizarraga , Asier Lopez-Eiguren , Kari Rummukainen , Jon Urrestilla

ALP domain walls without strings may be formed in the early Universe. We point out that such ALP domain walls lead to both isotropic and anisotropic birefringence of cosmic microwave background (CMB) polarization, which reflects spatial…

High Energy Physics - Phenomenology · Physics 2021-04-14 Fuminobu Takahashi , Wen Yin