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We propose to use a simple observable, the fractional area of "hot spots" in weak lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-shear regions are directly…

天体物理学 · 物理学 2008-09-24 Sheng Wang , Zoltan Haiman , Morgan May , John Kehayias

Here we consider the influence of the microlensing on the spectrum of a lensed object taking into account that composite emission is coming from different regions arranged subsequently around the central source. We assumed that the lensed…

宇宙学与河外天体物理 · 物理学 2018-03-14 Sasa Z. Simic , Luka C. Popovic , Predrag Jovanovic

Our peculiar motion in a homogeneous and isotropic universe imprints a dipole in the cosmic microwave background (CMB) temperature field and similarly imprints a dipole in the distribution of extragalactic radio sources on the sky. Each of…

宇宙学与河外天体物理 · 物理学 2022-01-05 Calum Murray

Measurement of Cosmic Microwave Background (CMB) temperature by Planck has resulted in extremely tight constraints on the $\Lambda$CDM model. However the data indicates a evidence of dipole modulated temperature fluctuations at large…

宇宙学与河外天体物理 · 物理学 2015-03-06 Suvodip Mukherjee

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One…

宇宙学与河外天体物理 · 物理学 2023-10-24 Giacomo Galloni , Mario Ballardini , Nicola Bartolo , Alessandro Gruppuso , Luca Pagano , Angelo Ricciardone

Several unexpected features have been observed in the microwave sky at large angular scales, both by WMAP an by Planck. Among those features is a lack of both variance and correlation on the largest angular scales, alignment of the lowest…

宇宙学与河外天体物理 · 物理学 2016-09-07 Dominik J. Schwarz , Craig J. Copi , Dragan Huterer , Glenn D. Starkman

The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\rm NL}^{\rm…

宇宙学与河外天体物理 · 物理学 2018-11-06 J. Colin Hill

The Milky Way can act as a large-scale weak gravitational lens of the cosmic microwave background (CMB). We study this effect using a photon ray-tracing code and a Galactic mass distribution with disk, bulge and halo components. For an…

宇宙学与河外天体物理 · 物理学 2015-06-22 Benjamin Czaja , Benjamin C. Bromley

We present a careful frequentist analysis of one- and two-point statistics of the hot and cold spots in the cosmic microwave background (CMB) data obtained by the Wilkinson Microwave Anisotropy Probe (WMAP). Our main result is the detection…

天体物理学 · 物理学 2007-05-23 David L. Larson , Benjamin D. Wandelt

Inflationary theory predicts that the observable Universe should be very close to flat, with a spatial-curvature parameter |Omega_K| < 10^-4. The WMAP satellite currently constrains |Omega_K| < 0.01, and the Planck satellite will be…

宇宙学与河外天体物理 · 物理学 2013-07-04 Philip Bull , Marc Kamionkowski

The presence of a dipolar statistical anisotropy in the spectrum of cosmic microwave background (CMB) fluctuations was reported by the Wilkinson Microwave Anisotropy Probe (WMAP), and has recently been confirmed in the Planck 2013 analysis…

宇宙学与河外天体物理 · 物理学 2014-04-29 Sugumi Kanno , Misao Sasaki , Takahiro Tanaka

The aberration and Doppler coupling effects of the Cosmic Microwave Background (CMB) were recently measured by the Planck satellite. The most straightforward interpretation leads to a direct detection of our peculiar velocity $\beta$,…

宇宙学与河外天体物理 · 物理学 2016-06-14 Omar Roldan , Alessio Notari , Miguel Quartin

We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background (CMB) with the Wilkinson Microwave Anisotropy Probe (WMAP) data and model the large-angle anomalies as the effect of the CMB quadrupole anisotropies…

宇宙学与河外天体物理 · 物理学 2014-11-20 Li-Ping He , Quan Guo

We study the apparent lack of power on large angular scales in the WMAP data. We confirm that although there is no apparent lack of power at large angular scales for the full-sky maps, the lowest multipoles of the WMAP data happen to have…

天体物理学 · 物理学 2007-05-23 Amir Hajian

We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…

天体物理学 · 物理学 2009-11-07 Asantha Cooray

If the primordial bispectrum is sufficiently large then the CMB hemispherical asymmetry may be explained by a large-scale mode of exceptional amplitude which perturbs the zeta two-point function. We extend previous calculations, which were…

宇宙学与河外天体物理 · 物理学 2016-06-27 Christian T. Byrnes , Donough Regan , David Seery , Ewan R. M. Tarrant

We present a blind multi-detector multi-component spectral matching method for all sky observations of the cosmic microwave background, working on the spherical harmonics basis. The method allows to estimate on a set of observation maps the…

天体物理学 · 物理学 2007-05-23 G. Patanchon , H. Snoussi , J. F. Cardoso , J. Delabrouille

We interpret the lack of large-angle temperature correlations and the apparent even-odd parity imbalance, observed in the cosmic microwave background by COBE, WMAP and Planck satellite missions, as a possible stringy signal ultimately…

宇宙学与河外天体物理 · 物理学 2022-05-27 Miguel-Angel Sanchis-Lozano

We investigate the distance-redshift relation in the simple void model. As discussed by Moffat and Tatarski, if the observer stays at the center of the void, the observed Hubble parameter is not so different from the background Hubble…

天体物理学 · 物理学 2016-08-30 Ken-ichi Nakao , Naoteru Gouda , Takeshi Chiba , Satoru Ikeuchi , Takashi Nakamura , Masaru Shibata

Voids are dominant features of the cosmic web. We revisit the cosmological information content of voids and connect void properties with the parameters of the background universe. We combine analytical results with a suite of large n-body…

宇宙学与河外天体物理 · 物理学 2025-03-24 Benjamin C. Bromley , Margaret J. Geller