中文
相关论文

相关论文: Machine Learning meets the redshift evolution of t…

200 篇论文

We use the Cosmic Microwave Background Anisotropies (CMBA) power spectra to constrain the cosmological variation of gravitational constant G. It is found that the sensitivity of CMBA to the variation of G is enhanced when G is required to…

天体物理学 · 物理学 2008-11-26 K. C. Chan , M. -C. Chu

In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor perturbations. We then specify our results to…

天体物理学 · 物理学 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

In order to extract cosmological information from observations of the millimeter and submillimeter sky, foreground components must first be removed to produce an estimate of the cosmic microwave background (CMB). We developed a…

宇宙学与河外天体物理 · 物理学 2020-11-10 Matthew A. Petroff , Graeme E. Addison , Charles L. Bennett , Janet L. Weiland

We constrain the history of reionization using the data from Planck 2015 Cosmic Microwave Background (CMB) temperature and polarization anisotropy observations. We also use prior constraints on the reionization history at redshifts…

宇宙学与河外天体物理 · 物理学 2017-12-13 Dhiraj Kumar Hazra , George F. Smoot

The linear anisotropies in the temperature of the cosmic microwave background (CMB) radiation and its polarization provide a clean picture of fluctuations in the universe some 370 kyr after the big bang. Simple physics connects these…

天体物理学 · 物理学 2007-05-23 Anthony Challinor

Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

宇宙学与河外天体物理 · 物理学 2015-12-30 Cheng Cheng , Qing-Guo Huang

The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that…

天体物理学 · 物理学 2009-10-22 Ruth Durrer

Observational evidence consistently shows that the universe is spatially flat and undergoes Lorentzian time dilation as a function of redshift. In combination, such discoveries suggest that a Minkowskian description of cosmology might be…

综合物理 · 物理学 2024-10-14 Artur Novais , A. L. B. Ribeiro

We extend our recent work on the effects of a time-varying fine-structure constant $\alpha$ in the cosmic microwave background, by providing a thorough analysis of the degeneracies between $\alpha$ and the other cosmological parameters, and…

天体物理学 · 物理学 2008-11-26 C. J. A. P. Martins , A. Melchiorri , R. Trotta , R. Bean , G. Rocha , P. P. Avelino , P. T. P. Viana

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological…

天体物理学 · 物理学 2009-09-29 Christopher O'Dell

Spectroscopic studies of high-redshift objects and increasingly precise data on the cosmic microwave background (CMB) are beginning to independently place strong complementary bounds on the epoch of hydrogen reionization. Parameter…

天体物理学 · 物理学 2009-11-07 Aparna Venkatesan

The Cosmic Microwave Background (CMB) provides a precious window on fundamental physics at very high energy scales, possibly including quantum gravity, GUTs and supersymmetry. The CMB has already enabled defect-based rivals to inflation to…

天体物理学 · 物理学 2009-09-11 John Ellis

High-precision measurements of the temperature and polarization anisotropies of the cosmic microwave background radiation have been previously employed to set robust constraints on dark matter annihilation during recombination. In this work…

宇宙学与河外天体物理 · 物理学 2013-05-30 Douglas P. Finkbeiner , Silvia Galli , Tongyan Lin , Tracy R. Slatyer

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

宇宙学与河外天体物理 · 物理学 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

The Cosmic Microwave Background (CMB), which permeates the entire Universe, is the radiation left over from just 380,000 years after the Big Bang. On very large scales, the CMB radiation field is smooth and isotropic, but the existence of…

The effects of reionization, occurring after standard recombination in cold dark matter-dominated models, on CMB anisotropies are investigated. Late-time reionization reduces the CMB anisotropies, in particular, on degree scales. It is…

天体物理学 · 物理学 2009-10-22 Naoshi Sugiyama , Joseph Silk , Nicola Vittorio

Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…

天体物理学 · 物理学 2007-05-23 Marc Kamionkowski

We have investigated some cosmological consequences of variation of the fine structure constant, $\alpha$, in the context of the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model. In this context, such a variation is attributed to electric…

广义相对论与量子宇宙学 · 物理学 2021-08-10 Yousef Bisabr

Spectral distortions of the cosmic microwave background (CMB) provide a unique tool for learning about the early phases of cosmic history, reaching deep into the primordial Universe. At redshifts $z<10^6$, thermalization processes become…

宇宙学与河外天体物理 · 物理学 2020-08-04 Jens Chluba , Andrea Ravenni , Sandeep Kumar Acharya

We present a new, model-independent method to reconstruct the temporal evolution of the speed of light $c(z)$ using astronomical observations. After validating our pipeline using mock datasets, we apply our method to the latest BAO and…

宇宙学与河外天体物理 · 物理学 2021-12-07 Dandan Wang , Hanyu Zhang , Jinglan Zheng , Yuting Wang , Gong-Bo Zhao