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Related papers: Correlation-based Beam Calibration of 21cm Intensi…

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We study the fluctuations of the light emitted by two identical incoherent point sources in a disordered environment. The intensity-intensity correlation function and the speckle contrast, obtained after proper temporal and configurational…

Optics · Physics 2015-02-09 R. Carminati , G. Cwilich , L. S. Froufe-Pérez , J. J. Sáenz

We present novel methods to perform plenoptic imaging at the diffraction limit by measuring intensity correlations of light. The first method is oriented towards plenoptic microscopy, a promising technique which allows refocusing and…

Image harmonization aims to adjust the foreground illumination in a composite image to make it harmonious. The existing harmonization methods can only produce one deterministic result for a composite image, ignoring that a composite image…

Computer Vision and Pattern Recognition · Computer Science 2024-07-23 Xinhao Tao , Tianyuan Qiu , Junyan Cao , Li Niu

Neutral hydrogen (HI) $21$-cm intensity mapping (IM) is a promising probe of the large-scale structures in the Universe. However, a few orders of magnitude brighter foregrounds obscure the IM signal. Here we use the Tapered Gridded…

Observations of the HI 21cm transition line promises to be an important probe into the cosmic dark ages and epoch of reionization. One of the challenges for the detection of this signal is the accuracy of the foreground source removal. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Datta , S. Bhatnagar , C. L. Carilli

Decoherence is a major obstacle to any practical implementation of quantum information processing. One of the leading strategies to reduce decoherence is dynamical decoupling --- the use of an external field to average out the effect of the…

Quantum Physics · Physics 2011-07-26 Ido Almog , Yoav Sagi , Goren Gordon , Guy Bensky , Gershon Kurizki , Nir Davidson

The HI 21cm absorption line is masked by bright foregrounds and systematic distortions that arise due to the chromaticity of the antenna used to make the observation coupling to the spectral inhomogeneity of these foregrounds. We…

Instrumentation and Methods for Astrophysics · Physics 2021-11-12 Dominic Anstey , Eloy de Lera Acedo , Will Handley

Existing image enhancement methods fall short of expectations because with them it is difficult to improve global and local image contrast simultaneously. To address this problem, we propose a histogram equalization-based method that adapts…

Computer Vision and Pattern Recognition · Computer Science 2022-09-15 Xiaomeng Wu , Takahito Kawanishi , Kunio Kashino

Measurements of the cosmic 21 cm signal need to achieve a high dynamic range to isolate it from bright foreground emissions. Calibration inaccuracies can compromise the spectral fidelity of the smooth foreground continuum, thereby limiting…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Pascal M. Keller , Bojan Nikolic , Nithyanandan Thyagarajan

We present a comprehensive set of forecasts for the cross-correlation signal between 21cm intensity mapping and galaxy redshift surveys. We focus on the data sets that will be provided by the SKAO for the 21cm signal, DESI and Euclid for…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-10 Maria Berti , Marta Spinelli , Matteo Viel

Observation of redshifted 21-cm signal from the Epoch of Reionization (EoR) is challenging due to contamination from the bright foreground sources that exceed the signal by several orders of magnitude. The removal of this very high…

We are presenting an Internal Linear Combination (ILC) CMB map, in which the foreground is reduced through harmonic variance minimization. We have derived our method by converting a general form of pixel-space approach into spherical…

Astrophysics · Physics 2009-09-29 Jaiseung Kim , Pavel Naselsky , Per Rex Christensen

The cross-correlation between fluctuations in the electron scattering optical depth $\tau_{\rm es}$ as probed by future Cosmic Microwave Background (CMB) experiments, and fluctuations in the 21cm differential brightness temperature $\Delta…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-07 Anirban Roy , Andrea Lapi , David Spergel , Soumen Basak , Carlo Baccigalupi

Line intensity mapping using atomic hydrogen (HI) has the potential to efficiently map large volumes of the universe if the signal can be successfully separated from overwhelmingly bright radio foreground emission. This motivates…

Cross-correlating the data of neutral hydrogen (HI) 21cm intensity mapping with galaxy surveys is an effective method to extract astrophysical and cosmological information. In this work, we investigate the cross-correlation of MeerKAT…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Yuer Jiang , Yan Gong , Meng Zhang , Qi Xiong , Xingchen Zhou , Furen Deng , Xuelei Chen , Yin-Zhe Ma , Bin Yue

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

Spectral measurements of the 21 cm monopole background have the promise of revealing the bulk energetic properties and ionization state of our universe from z ~ 6-30. Synchrotron foregrounds are orders of magnitude larger than the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-08 Eric R. Switzer , Adrian Liu

The reconfigurable intelligent surface (RIS) technology has attracted interest due to its promising coverage and spectral efficiency features. However, some challenges need to be addressed to realize this technology in practice. One of the…

Signal Processing · Electrical Eng. & Systems 2020-10-21 Mehmet Ali Aygul , Mahmoud Nazzal , Huseyin Arslan

A method involving intensity correlation measurements is described, which allows for the complete removal of Doppler broadening in the emission of electromagnetic radiation from far-away sources that are inaccessible to conventional…

Optics · Physics 2021-04-22 R. Merlin , N. Green , I. Szapudi , G. Tarle

While model-based reconstruction methods have been successfully applied to flat-panel cone-beam CT (FP-CBCT) systems, typical implementations ignore both spatial correlations in the projection data as well as system blurs due to the…

Medical Physics · Physics 2017-06-20 Steven Tilley , Jeffrey H. Siewerdsen , J. Webster Stayman