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The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters…

宇宙学与河外天体物理 · 物理学 2016-06-21 Krzysztof Bolejko , M. Ahsan Nazer , David L. Wiltshire

Low amplitude (linear regime) cosmic density fluctuations lead to spatial variations in the locally measurable value of $H_0$ (denoted as $H_L$), $\delta_H \equiv (H_L-H_0)/H_0$, which are of order 3-6% (95% confidence interval) in a sphere…

天体物理学 · 物理学 2009-10-30 Yun Wang , David N. Spergel , Edwin L. Turner

We demonstrate that constraints on cosmological parameters from the distribution of clusters as a function of redshift (dN/dz) are complementary to accurate angular diameter distance (D_A) measurements to clusters, and their combination…

天体物理学 · 物理学 2009-11-10 S. M. Molnar , Z. Haiman , M. Birkinshaw , R. F. Mushotzky

While the cosmic microwave background (CMB) dipole is largely assumed entirely kinematic, there appears evidence that a part of it is primordial. Such possibility arises in models implying a tilt, interpreted as a dark flow, across the…

宇宙学与河外天体物理 · 物理学 2022-06-29 A. Kashlinsky , F. Atrio-Barandela

Images of dust continuum and carbon monoxide (CO) line emission are powerful tools for deducing structural characteristics of galaxies, such as disk sizes, H$_2$ gas velocity fields and enclosed H$_2$ and dynamical masses. We report on a…

Cosmicflows-3 distances and inferred peculiar velocities of galaxies have permitted the reconstruction of the structure of over and under densities within the volume extending to 0.05c. This study focuses on the under dense regions,…

宇宙学与河外天体物理 · 物理学 2019-07-31 R Brent Tully , Daniel Pomarede , Romain Graziani , Helene M Courtois , Yehuda Hoffman , Edward J Shaya

Cosmic Microwave Background (CMB) is a powerful probe to study the early universe and various cosmological models. Weak gravitational lensing affects the CMB by changing its power spectrum, but meanwhile, it also carries information about…

宇宙学与河外天体物理 · 物理学 2021-06-09 Chandra Shekhar Saraf

Galaxy groups, which have hardly been looked at in MOND, afford probing the acceleration discrepancies in regions of system-parameter space that are not accessible in well-studied galactic systems, such as galaxies, galaxy clusters, and…

星系天体物理 · 物理学 2018-12-04 Mordehai Milgrom

We present cosmological constraints from a joint analysis including the power spectrum and bispectrum of BOSS galaxies based on the Effective Field Theory of Large-Scale Structure predictions at one-loop order, in combination with CMB data…

宇宙学与河外天体物理 · 物理学 2023-12-27 Simon Spaar , Pierre Zhang

We examine the sky distribution of radio galaxies in the NRAO VLA Sky Survey (NVSS) and the Rapid ASKAP Continuum Survey (RACS). Analyses of these samples have reported tension between their inferred dipoles and the kinematic dipole of the…

宇宙学与河外天体物理 · 物理学 2024-06-05 Oliver T. Oayda , Vasudev Mittal , Geraint F. Lewis , Tara Murphy

We use numerical simulations to study the relation between the velocity of the Local Group and its gravitational acceleration. This relation serves as a test for the kinematic origin of the CMB dipole and as a method for estimating beta. We…

天体物理学 · 物理学 2007-05-23 P. Ciecielag , M. Chodorowski , A. Kudlicki

Recent re-calibration of the Type Ia supernova (SNe~Ia) magnitude-redshift relation combined with cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) data have provided excellent constraints on the standard cosmological…

宇宙学与河外天体物理 · 物理学 2017-08-02 Suhail Dhawan , Ariel Goobar , Edvard Mörtsell , Rahman Amanullah , Ulrich Feindt

The 6dF Galaxy Survey (6dFGS) and the 2MASS Redshift Survey (2MRS) provide the most complete maps of the large-scale structures and motions in the nearby universe. These maps have been used to reconstruct the density field in the local…

天体物理学 · 物理学 2015-05-13 Matthew Colless

We present new evidence for a large deficiency in the local galaxy distribution situated in the 4000 sq.deg. APM survey area. We use models guided by the 2dF Galaxy Redshift Survey (2dFGRS) n(z) as a probe of the underlying LSS. We first…

天体物理学 · 物理学 2007-05-23 W. J. Frith , P. J. Outram , T. Shanks

We present the results of a set of high resolution chemo-dynamical simulations of dwarf galaxies in a $\Lambda$CDM cosmology. Out of an original 3.4 Mpc$^3$/h$^3$ cosmological box, a sample of 27 systems are zoomed-in from z=70 to z=0. Gas…

星系天体物理 · 物理学 2018-08-29 Yves Revaz , Pascale Jablonka

(abridged) Predictions of the Concordance Cosmological Model (CCM) of the structures in the environment of large spiral galaxies are compared with observed properties of Local Group galaxies. Five new most probably irreconcilable problems…

宇宙学与河外天体物理 · 物理学 2015-05-19 P. Kroupa , B. Famaey , K. S. de Boer , J. Dabringhausen , M. S. Pawlowski , C. M. Boily , H. Jerjen , D. Forbes , G. Hensler , M. Metz

Recent observations have identified a significant 4.9$\sigma$ tension between the cosmic dipole inferred from galaxy number counts and that derived from the Cosmic Microwave Background (CMB), suggesting a potential deviation from the…

宇宙学与河外天体物理 · 物理学 2025-07-29 Ge Chen , Chengcheng Han , Linwei Qiu

Observations of molecular gas near the Galactic centre ($| l | < 10^\circ$, $| b | < 1^\circ$) reveal the presence of a distinct population of enigmatic compact clouds which are characterised by extreme velocity dispersions ($\Delta v >…

The spherical infall model first developed by Lema\^{i}tre and Tolman was modified in order to include the effects of a dark energy term. The resulting velocity-distance relation was evaluated numerically. This equation, when fitted to…

天体物理学 · 物理学 2016-08-16 Sébastien Peirani , José Antonio De Freitas Pacheco

Measurements of the SNe Ia Hubble diagram which suggest that the universe is accelerating due to the effect of dark energy may be biased because we are located in a 200-300 Mpc underdense "void" which is expanding 20-30% faster than the…

天体物理学 · 物理学 2011-02-09 Paul Hunt , Subir Sarkar