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相关论文: A wavelet-Galerkin algorithm of the E/B decomposit…

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We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

天体物理学 · 物理学 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

We present a method to delens the acoustic peaks of the CMB temperature and polarization power spectra internally, using lensing maps reconstructed from the CMB itself. We find that when delensing CMB acoustic peaks with a lensing potential…

宇宙学与河外天体物理 · 物理学 2017-05-31 Neelima Sehgal , Mathew S. Madhavacheril , Blake Sherwin , Alexander van Engelen

The detection of large angular scale $B$-mode in the Cosmic Microwave Background (CMB) polarization signal will open a direct window into not only the primary CMB anisotropies caused by the primordial gravitational waves (PGW) originating…

宇宙学与河外天体物理 · 物理学 2023-10-26 Divesh Jain , Suvodip Mukherjee , Tirthankar Roy Choudhury

Cosmological Birefringence (CB), a rotation of the polarization plane of radiation coming to us from distant astrophysical sources, may reveal parity violation in either the electromagnetic or gravitational sectors of the fundamental…

宇宙学与河外天体物理 · 物理学 2013-05-30 Amit P. S. Yadav , Meir Shimon , Brian G. Keating

The aim of this project is to recover the CMB anisotropies maps in temperature and polarized intensity by means of a deep convolutional neural network (CNN) which, after appropiate training, can remove the foregrounds from Planck and…

宇宙学与河外天体物理 · 物理学 2024-05-29 A. Quintana-Estellés , B. Ruiz-Granados , P. Ruiz-Lapuente

The primary source of systematic uncertainty in the quest for the B-mode polarization of the Cosmic Microwave Background (CMB) introduced by primordial gravitational waves is polarized thermal emission from Galactic dust. Therefore,…

In this work, we investigate the propagation of electromagnetic waves in the Cole-Cole dispersive medium by using the discontinuous Galerkin (DG) method to solve the coupled time-domain Maxwell's equations and polarization equation. We…

数值分析 · 数学 2022-08-25 Jiangming Xie , Maojun Li , Miao-Jung Yvonne Ou

We consider discontinuous Galerkin methods for an elliptic distributed optimal control problem and we propose multigrid methods to solve the discretized system. We prove that the $W$-cycle algorithm is uniformly convergent in the energy…

数值分析 · 数学 2023-05-11 Sijing Liu

Future cosmic microwave background (CMB) polarisation experiments aim to measure an unprecedentedly small signal - the primordial gravity wave component of the polarisation field B-mode. To achieve this, they will analyse huge datasets,…

宇宙学与河外天体物理 · 物理学 2015-05-14 D. Sutton , J. A. Zuntz , P. G. Ferreira , M. L. Brown , H. K. Eriksen , B. R. Johnson , A. Kusaka , S. K. Naess , I. K. Wehus

We present the first detailed case study using quadratic estimators (QE) to diagnose and remove systematics present in observed Cosmic Microwave Background (CMB) maps. In this work we focus on the temperature to polarization leakage. We use…

宇宙学与河外天体物理 · 物理学 2021-07-13 Joel Williams , Nialh McCallum , Aditya Rotti , Daniel Thomas , Richard Battye , Michael L. Brown

We analyze the possibility of delensing CMB polarization maps using foreground weak lensing (WL) information. We build an estimator of the CMB lensing potential out of optimally combined projected potential estimators to different source…

天体物理学 · 物理学 2008-11-26 Laura Marian , Gary M. Bernstein

In this paper we will consider distributed Linear-Quadratic Optimal Control Problems dealing with Advection-Diffusion PDEs for high values of the P\'eclet number. In this situation, computational instabilities occur, both for steady and…

数值分析 · 数学 2024-05-03 Fabio Zoccolan , Maria Strazzullo , Gianluigi Rozza

We present efficient algorithms for CMB lensing simulation and power spectrum es- timation for flat-sky CMB polarization maps. We build a pure B-mode estimator to remedy E to B leakage due to partial sky coverage. We show that our…

宇宙学与河外天体物理 · 物理学 2013-11-14 Thibaut Louis , Sigurd Næss , Sudeep Das , Joanna Dunkley , Blake Sherwin

In this paper, we prove convergence rates for time discretisation schemes for semi-linear stochastic evolution equations with additive or multiplicative Gaussian noise, where the leading operator $A$ is the generator of a strongly…

数值分析 · 数学 2024-12-19 Katharina Klioba , Mark Veraar

The main result of this paper is the discretization of Hamiltonian systems of the form $\ddot x = -K \nabla W(x)$, where $K$ is a constant symmetric matrix and $W\colon\mathbb{R}^n\to \mathbb{R}$ is a polynomial of degree $d\le 4$ in any…

动力系统 · 数学 2023-07-14 Robert I McLachlan , David I McLaren , G R W Quispel

The aim of this work is to introduce and analyze a finite element discontinuous Galerkin method on polygonal meshes for the numerical discretization of acoustic waves propagation through poroelastic materials. Wave propagation is modeled by…

数值分析 · 数学 2021-04-14 Paola F. Antonietti , Michele Botti , Ilario Mazzieri , Simone Nati Poltri

Training neural network models with discrete (categorical or structured) latent variables can be computationally challenging, due to the need for marginalization over large or combinatorial sets. To circumvent this issue, one typically…

机器学习 · 计算机科学 2020-12-29 Gonçalo M. Correia , Vlad Niculae , Wilker Aziz , André F. T. Martins

In inflationary models, gravitational waves are produced and generate B-type polarization in the CMB. Since B polarization is only generated by gravity waves it does not suffer from the cosmic variance. A perfect decomposition of the CMB…

天体物理学 · 物理学 2009-11-13 Mihail Amarie , Christopher Hirata , Uros Seljak

A discretisation method with the $H_{\rm div}$ inner product for the electric field integral equation~(EFIE) is proposed. The EFIE with the conventional Galerkin discretisation shows bad accuracy for problems with a small frequency, a…

数值分析 · 数学 2017-06-22 Kazuki Niino , Sho Akagi , Naoshi Nishimura