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The hot gas in clusters of galaxies creates a distinctive spectral distortion in the cosmic microwave background (CMB) via the Sunyaev-Zel'dovich (SZ) effect. The spectral signature of the SZ can be used to measure the CMB temperature at…

宇宙学与河外天体物理 · 物理学 2022-02-09 Gemma Luzzi , Emanuele D'Angelo , Hervé Bourdin , Federico De Luca , Pasquale Mazzotta , Filippo Oppizzi , Gianluca Polenta

Standard cosmology has long been plagued by a number of persistent problems. The origin of the apparent acceleration of the cosmic expansion remains enigmatic. The cosmological constant has been reintroduced as a free parameter with a value…

综合物理 · 物理学 2023-02-28 Jan O. Stenflo

Much of modern cosmology relies on the Cosmological Principle, the assumption that the Universe is isotropic and homogeneous on sufficiently large scales, but it remains worthwhile to examine cosmological models that violate this principle…

宇宙学与河外天体物理 · 物理学 2024-11-01 Ananda F. Smith , Craig J. Copi , Glenn D. Starkman

Current observational bounds on dark energy depend on assumptions about the curvature of the universe. We present a simple and efficient method for incorporating constraints from CMB anisotropy data, and use it to derive constraints on…

天体物理学 · 物理学 2010-04-06 Yun Wang , Pia Mukherjee

Unparticle cosmology gives an unconventional outlook on the dark sector of cosmology, increasingly challenging $\Lambda\mbox{CDM}$ by $H_0$-tension. This model derives from a finite temperature broken conformal symmetry of radiation,…

宇宙学与河外天体物理 · 物理学 2023-03-31 Maurice H. P. M. van Putten , Maryam Aghaei Abchouyeh

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

天体物理学 · 物理学 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

We suggest that the cosmic microwave background (CMB) temperature correlation function C(theta) as a function of angle provides a direct connection between experimental data and the fundamental cosmological quantities. The evolution of…

天体物理学 · 物理学 2009-10-31 Sergei Bashinsky , Edmund Bertschinger

Cosmology constraints serve as a crucial criterion in discriminating cosmological models. The traditional combined method to constrain the cosmological parameters designates the corresponding theoretical value and observational data as…

宇宙学与河外天体物理 · 物理学 2023-10-17 Wei Hong , Kang Jiao , Yu-Chen Wang , Tingting Zhang , Tong-Jie Zhang

The determination of the Hubble constant has been a central goal in observational astrophysics for nearly 100 years. Extraordinary progress has occurred in recent years on two fronts: the cosmic distance ladder measurements at low redshift…

宇宙学与河外天体物理 · 物理学 2014-10-14 C. L. Bennett , D. Larson , J. L. Weiland , G. Hinshaw

Driven by the CMB temperature-redshift ($T$-$z$) relation as demanded by deconfining SU(2) Yang-Mills thermodynamics, an according cosmological model is proposed and analysed. This model -- SU(2)$_\CMB$ -- exhibits a dark sector,…

综合物理 · 物理学 2018-12-13 Steffen Hahn , Ralf Hofmann , Daniel Kramer

We search for the signature of parity-violating physics in the cosmic microwave background, called cosmic birefringence, using the Planck data release 4. We initially find a birefringence angle of $\beta=0.30\pm0.11$ (68% C.L.) for nearly…

We use the Simon, Verde, & Jimenez (2005) determination of the redshift dependence of the Hubble parameter to constrain cosmological parameters in three dark energy cosmological models. We consider the standard $\Lambda$CDM model, the XCDM…

天体物理学 · 物理学 2011-02-11 Lado Samushia , Bharat Ratra

The absolute temperature of the cosmic microwave background (CMB) has been measured at a frequency of 1280 MHz. The observation was made with a modified version of the L-band receiver used in the Giant Metre wavelength Radio Telescope…

天体物理学 · 物理学 2007-05-23 A. Raghunathan , R. Subrahmanyan

Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are…

天体物理学 · 物理学 2009-11-10 Marco Bersanelli , Davide Maino , Aniello Mennella

The COBE microwave background temperature fluctuations and the abundance of local rich clusters of galaxies provide the two most powerful constraints on cosmological models. When all variants of the standard cold dark matter (CDM) model are…

天体物理学 · 物理学 2009-10-30 Renyue Cen

We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter $w$ that scales with the $\arctan$ of the redshift. The free parameters of the model are three constants: $\Omega_{b0}$,…

宇宙学与河外天体物理 · 物理学 2015-11-17 R. R. Cuzinatto , L. G. Medeiros , E. M. de Morais

The improving sensitivity of measurements of the kinetic Sunyaev-Zel'dovich (SZ) effect opens a new window into the thermodynamic properties of the baryons in halos. We propose a methodology to constrain these thermodynamic properties by…

宇宙学与河外天体物理 · 物理学 2017-12-13 Nicholas Battaglia , Simone Ferraro , Emmanuel Schaan , David Spergel

Recent measurements of the temperature fluctuations of the cosmic microwave background (CMB) radiation from the WMAP satellite provide indication of a non-Gaussian behavior. Although the observed feature is small, it is detectable and…

天体物理学 · 物理学 2008-11-26 Armando Bernui , Constantino Tsallis , Thyrso Villela

We devise a measure n(r) to quantify a robust feature in the coherent cosmic perturbations, namely the narrowness of the first peak in the power spectrum of the Cosmic Microwave Background (CMB) anisotropy. A maximum-likelihood analysis…

天体物理学 · 物理学 2007-05-23 Jiun-Huei Proty Wu

We study constraints on allowed reionization histories by comparing predictions of a physical semi-numerical model with secondary temperature and polarization anisotropies of the cosmic microwave background (CMB). Our model has four free…

宇宙学与河外天体物理 · 物理学 2020-12-02 Tirthankar Roy Choudhury , Suvodip Mukherjee , Sourabh Paul