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Cosmological parameter constraints from the CMB power spectra alone suffer several well-known degeneracies. These degeneracies can be broken by numerical artefacts and also a variety of physical effects that become quantitatively important…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-23 Cullan Howlett , Antony Lewis , Alex Hall , Anthony Challinor

Compressed Sensing suggests that the required number of samples for reconstructing a signal can be greatly reduced if it is sparse in a known discrete basis, yet many real-world signals are sparse in a continuous dictionary. One example is…

Information Theory · Computer Science 2015-07-24 Yuanxin Li , Yuejie Chi

We introduce a new estimator of the CMB lensing power spectrum, together with its likelihood, based on iterative lensing reconstruction. Despite the increased complexity of the lensing maps, this estimator shares similarities with the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-17 Louis Legrand , Julien Carron

Deep cosmic microwave background polarization experiments allow a very precise internal reconstruction of the gravitational lensing signal in pricinple. For this aim, likelihood-based or Bayesian methods are typically necessary, where very…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-25 Martin Reinecke , Sebastian Belkner , Julien Carron

Jacobi matrices are parametrized by their eigenvalues and norming constants (first coordinates of normalized eigenvectors): this coordinate system breaks down at reducible tridiagonal matrices. The set of real symmetric tridiagonal matrices…

Numerical Analysis · Mathematics 2007-05-23 Ricardo S. Leite , Nicolau C. Saldanha , Carlos Tomei

We present a noise deconvolution technique to remove a wide class of noises when performing arbitrary measurements on qubit systems. In particular, we derive the inverse map of the most common single qubit noisy channels and exploit it at…

Quantum Physics · Physics 2022-11-16 Stefano Mangini , Lorenzo Maccone , Chiara Macchiavello

Bayesian approximate message passing (BAMP) is an efficient method in compressed sensing that is nearly optimal in the minimum mean squared error (MMSE) sense. Bayesian approximate message passing (BAMP) performs joint recovery of multiple…

Information Theory · Computer Science 2019-01-30 Gabor Hannak , Alessandro Perelli , Norbert Goertz , Gerald Matz , Mike E. Davies

This article describes a fast iterative algorithm for image denoising and deconvolution with signal-dependent observation noise. We use an optimization strategy based on variable splitting that adapts traditional Gaussian noise-based…

Computer Vision and Pattern Recognition · Computer Science 2012-04-16 Ayan Chakrabarti , Todd Zickler

The density field reconstruction technique has been widely used for recovering the Baryon Acoustic Oscillation (BAO) feature in galaxy surveys that has been degraded due to nonlinearities. Recent studies advocated adopting iterative steps…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-02 Hee-Jong Seo , Atsuhisa Ota , Marcel Schmittfull , Shun Saito , Florian Beutler

We present a technique for the blind separation of components in CMB data. The method uses a spectral EM algorithm which recovers simultaneously component templates, their emission law as a function of wavelength, and noise levels. We test…

We discuss a method for a model independent reconstruction of the CMB temperature fluctuation power spectrum on small and intermediate scales that is geared to individual experiments. The importance of off-diagonal correlations for…

Astrophysics · Physics 2009-09-25 Martin White

This paper demonstrates a practical method that can correct spatial varying blur from a set of images of the same object. The algorithm jointly estimates the object and local point spread functions~(PSF). The method prioritizes sections…

Image and Video Processing · Electrical Eng. & Systems 2020-11-04 Wouter van de Ketterij , Oleg Soloviev , Michel Verhaegen

The presence of astrophysical emissions in microwave observations forces us to perform component separation to extract the Cosmic Microwave Background (CMB) signal. However, even in the most optimistic cases, there are still strongly…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-26 C. Gimeno-Amo , E. Martínez-González , R. B. Barreiro

In this study, we apply the Analytical method of Blind Separation (ABS) of the cosmic microwave background (CMB) from foregrounds to estimate the CMB temperature power spectrum from multi-frequency microwave maps. We test the robustness of…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-21 Jian Yao , Le Zhang , Yuxi Zhao , Pengjie Zhang , Larissa Santos , Jun Zhang

We introduce a pixel space method to detect dipole modulation or hemispherical power asymmetry in the cosmic microwave background (CMB) polarization. The method relies on the use of squared total polarized flux whose ensemble average picks…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Shamik Ghosh , Pankaj Jain

Over the last decade, measurements of the CMB anisotropy has spearheaded the remarkable transition of cosmology into a precision science. However, addressing the systematic effects in the increasingly sensitive, high resolution, `full' sky…

Astrophysics · Physics 2009-03-31 Sanjit Mitra , Anand S. Sengupta , Subharthi Ray , Rajib Saha , Tarun Souradeep

We describe a new multi-scale deconvolution algorithm that can also be used in multi-frequency mode. The algorithm only affects the minor clean loop. In single-frequency mode, the minor loop of our improved multi-scale algorithm is over an…

Instrumentation and Methods for Astrophysics · Physics 2017-08-02 A. R. Offringa , O. Smirnov

Mild, unavoidable deviations from circular-symmetry of instrumental beams along with scan strategy can give rise to measurable Statistical Isotropy (SI) violation in Cosmic Microwave Background (CMB) experiments. If not accounted properly,…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-06 Nidhi Pant , Santanu Das , Aditya Rotti , Sanjit Mitra , Tarun Souradeep

We present a signal-foreground separation algorithm for filtering observational data to extract spectral distortions of the cosmic microwave background (CMB). Our linear method, called the least response method (LRM), is based on the idea…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-16 J. -P. Maillard , A. Mihalchenko , D. Novikov , A. Osipova , S. Pilipenko , J. Silk

The motion of the solar system barycenter with respect to the cosmic microwave background (CMB) induces a very large apparent dipole component into the CMB brightness map at the 3 mK level. In this Letter we discuss another kinematic effect…

Astrophysics · Physics 2009-11-11 Scott Burles , Saul Rappaport
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