中文
相关论文

相关论文: "Sample Variance" in Small-Scale CMB Anisotropy Ex…

200 篇论文

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

宇宙学与河外天体物理 · 物理学 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

On large angular scales (greater than about 60 degrees), the two-point angular correlation function of the temperature of the cosmic microwave background (CMB), as measured (outside of the plane of the Galaxy) by the Wilkinson Microwave…

宇宙学与河外天体物理 · 物理学 2015-05-18 Devdeep Sarkar , Dragan Huterer , Craig J. Copi , Glenn D. Starkman , Dominik J. Schwarz

We discuss methods for estimating EB and TB spectra of the Cosmic Microwave Background anisotropy maps covering limited sky area. Such odd-parity correlations are expected to vanish whenever parity is not broken. As this is indeed the case…

宇宙学与河外天体物理 · 物理学 2012-10-18 Julien Grain , Matthieu Tristram , Radek Stompor

We discuss all-sky convolution of the instrument beam with the sky signal in polarimetry experiments, such as the Planck mission which will map the temperature anisotropy and polarization of the cosmic microwave background (CMB). To account…

We present a CMB temperature power spectrum measurement at large angular scales from WMAP and Planck maps that were cleaned of foregrounds using a template-based approach described in a companion paper. We recover essentially the full-sky…

宇宙学与河外天体物理 · 物理学 2025-09-05 Hayley C. Nofi , Graeme E. Addison , Charles L. Bennett , Laura Herold , J. L. Weiland

We investigate weak lensing effect on cosmic microwave background (CMB) in the presence of dipole anisotropy. The approach of flat-sky approximation is considered. We determine the functions $\sigma_0^2$ and $\sigma_2^2$ that appear in…

宇宙学与河外天体物理 · 物理学 2019-07-24 Abhineet Agarwal , Naveen K. Singh , Pankaj Jain , Prabhakar Tiwari

The Cosmic Microwave Background (CMB) anisotropy power on the largest angular scales observed both by WMAP and COBE DMR appears to be lower than the one predicted by the standard model of cosmology with almost scale free primordial…

天体物理学 · 物理学 2009-09-29 Carlo R. Contaldi , Marco Peloso , Lev Kofman , Andrei Linde

We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…

The cosmological principle, asserting large-scale homogeneity and isotropy, underpins the standard model of cosmology. Testing its validity using independent astronomical probes remains crucial for understanding the global structure of the…

高能天体物理现象 · 物理学 2026-02-13 Debosi Mondal , Biswajit Pandey , Amit Mondal

Since the discovery of the Cosmic Microwave Background (CMB) in 1965, characterization of the CMB anisotropy angular power spectrum has become somewhat of a holy grail for experimental cosmology. Because CMB anisotropy measurements are…

天体物理学 · 物理学 2017-08-23 A. D. Miller

Photometric galaxy surveys probe the late-time Universe where the density field is highly non-Gaussian. A consequence is the emergence of the super-sample covariance (SSC), a non-Gaussian covariance term that is sensitive to fluctuations on…

宇宙学与河外天体物理 · 物理学 2022-03-23 S. Gouyou Beauchamps , F. Lacasa , I. Tutusaus , M. Aubert , P. Baratta , A. Gorce , Z. Sakr

We present a novel approach to disentangle two key contributions to the largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole due to clustering and anisotropic geometry, and (ii) the kinematic dipole due to our…

宇宙学与河外天体物理 · 物理学 2021-11-09 Tobias Nadolny , Ruth Durrer , Martin Kunz , Hamsa Padmanabhan

We test the isotropy of Hubble expansion by combining several probes for the first time, constructing full-sky maps of expansion rate variation using Type Ia supernovae, fundamental plane galaxies, and CMB temperature fluctuations. We find…

宇宙学与河外天体物理 · 物理学 2025-12-04 Alan Junzhe Zhou , Scott Dodelson , Daniel Scolnic

Based on general relativity, it can be argued that deviations from a uniform Hubble flow should be thought of as variations in the Universe's expansion velocity field, rather than being thought of as peculiar velocities with respect to a…

天体物理学 · 物理学 2008-11-26 M. L. McClure , C. C. Dyer

We apply Simulation-Based Inference ('SBI') to the cosmic dipole problem for the first time, measuring the distribution of quasar counts over the sky in the CatWISE2020 ('CatWISE') sample. We show that the quadrupole anisotropy in CatWISE…

宇宙学与河外天体物理 · 物理学 2026-02-06 Oliver T. Oayda , Geraint F. Lewis

Current measurements of the weak lensing signal induced by large scale structure provide useful constraints on a range of cosmological parameters. However, the ultimate succes of this technique depends on the accuracy with which one can…

天体物理学 · 物理学 2009-11-07 Henk Hoekstra

The two main advantages of space-based observation of extreme energy ($\gtrsim5\times10^{19}$ eV) cosmic rays (EECRs) over ground based observatories are the increased field of view and the full-sky coverage with nearly uniform systematics…

高能天体物理现象 · 物理学 2015-07-20 Peter B. Denton , Thomas J. Weiler

We investigate anomalies reported in the Cosmic Microwave Background maps from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on very large angular scales and discuss possible interpretations. Three independent anomalies involve…

天体物理学 · 物理学 2009-07-09 Angelica de Oliveira-Costa , Max Tegmark , Matias Zaldarriaga , Andrew Hamilton

We reanalyse Cosmic Microwave Background data from experiments probing both large and small scales. We assume that measured anisotropies are due not only to primary fluctuations but also, especially at small scales, to secondary effects…

天体物理学 · 物理学 2007-05-23 Marian Douspis , Nabila Aghanim , Mathieu Langer

We study the large-scale anisotropy of the Universe by measuring the dipole in the angular distribution of a flux-limited, all-sky sample of 1.36 million quasars observed by the Wide-field Infrared Survey Explorer (WISE). This sample is…

宇宙学与河外天体物理 · 物理学 2021-03-01 Nathan Secrest , Sebastian von Hausegger , Mohamed Rameez , Roya Mohayaee , Subir Sarkar , Jacques Colin