中文
相关论文

相关论文: Constraints on a Bianchi type I spacetime extensio…

200 篇论文

We present constraints on the cosmological constant lambda_0 and the density parameter Omega_0 from joint constraints from the analyses of gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS), optical…

天体物理学 · 物理学 2007-05-23 J. F. Macias-Perez , P. Helbig , R. Quast , A. Wilkinson , R. D. Davies

The past, present and future of cosmic microwave background (CMB) anisotropy research is discussed, with emphasis on the Boomerang and Maxima balloon experiments. These data are combined with large scale structure (LSS) information and high…

We use joint likelihood analyses of combinations of fifteen cosmic microwave background (CMB) anisotropy data sets from the DMR, UCSB South Pole 1994, Python I--III, ARGO, MAX 4 and 5, White Dish, OVRO, and SuZIE experiments to constrain…

We use Python I, II, and III cosmic microwave background anisotropy data to constrain cosmogonies. We account for the Python beamwidth and calibration uncertainties. We consider open and spatially-flat-Lambda cold dark matter cosmogonies,…

We investigate a phenomenological extension of the standard $\Lambda$CDM framework, the $\Omega_1\Omega_2$-$\Lambda$CDM model, in which the total energy density of the universe is expanded in powers of $1+z$. This parameterization recovers…

宇宙学与河外天体物理 · 物理学 2026-02-20 Suresh Kumar

We discuss the cosmological implications of the new constraints on the power spectrum of the Cosmic Microwave Background Anisotropy derived from a new high resolution analysis of the MAXIMA-1 measurement (Lee et al. 2001). The power…

We explore the possible advantages of extending the $\Lambda$CDM model by more realistic backgrounds compared to its spatially flat RW spacetime assumption, while preserving the underpinning physics; in particular, by simultaneously…

宇宙学与河外天体物理 · 物理学 2023-01-05 Ozgur Akarsu , Eleonora Di Valentino , Suresh Kumar , Maya Ozyigit , Shivani Sharma

In this study, we have demonstrated the expansion history of an axially symmetric Bianchi type-I model of the universe. Our model as of now presents an accelerating universe, which had been in the decelerating phase in the past. Roles of…

广义相对论与量子宇宙学 · 物理学 2022-11-30 Vinod Kumar Bhardwaj , Archana Dixit , Rita Rani , G. K. Goswami , Anirudh Pradhan

I review the basic theory of the cosmic microwave background anisotropies in adiabatic cold dark matter cosmologies. The latest observational results on the CMB power spectrum are consistent with the simplest inflationary models and…

天体物理学 · 物理学 2009-09-25 G. Efstathiou

The Universe's initial conditions, in particular baryon and cold dark matter (CDM) isocurvature perturbations, are poorly constrained on sub-Mpc scales. In this paper, we develop a new formalism to compute the effect of small-scale baryon…

宇宙学与河外天体物理 · 物理学 2021-11-24 Nanoom Lee , Yacine Ali-Haïmoud

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 standard cosmological model is challenged by an ever-growing collection of observations, which invites (and stimulates) inquiry into possible additions and/or alterations. One such alteration comes from letting cosmic isotropy -- as…

广义相对论与量子宇宙学 · 物理学 2026-04-22 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat $\Lambda$CDM model. Unlike…

宇宙学与河外天体物理 · 物理学 2018-09-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…

宇宙学与河外天体物理 · 物理学 2022-05-31 Shulei Cao , Bharat Ratra

We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…

宇宙学与河外天体物理 · 物理学 2014-03-03 Sabir Ramazanov , Grigory Rubtsov

We constrain the deviation of adiabatic evolution of the Universe using the data on the Cosmic Microwave Background (CMB) temperature anisotropies measured by the {\it Planck} satellite and a sample of 481 X-ray selected clusters with…

宇宙学与河外天体物理 · 物理学 2015-07-31 I. de Martino , R. Génova-Santos , F. Atrio-Barandela , H. Ebeling , A. Kashlinsky , D. Kocevski , C. J. A. P. Martins

The cosmic curvature $\Omega_{K}$ is an important parameter related to the inflationary cosmology and the ultimate fate of the universe. In this work, we adopt the non-CMB observations to constrain $\Omega_{K}$ in the $\Lambda$CDM model and…

宇宙学与河外天体物理 · 物理学 2025-09-12 Peng-Ju Wu , Xin Zhang

A recently proposed generalized entropy by Luciano and Saridakis extends the standard Boltzmann-Gibbs and Bekenstein-Hawking framework through a microscopically motivated construction involving two independent entropic exponents. When…

The standard cosmological model predicts statistically isotropic cosmic microwave background (CMB) fluctuations characterized by the CMB temperature coefficients $a_{\ell m}$ being independent Gaussian random variables with zero mean and…

宇宙学与河外天体物理 · 物理学 2026-03-17 Joann Jones , Craig J. Copi , Glenn D. Starkman , Yashar Akrami

We present constraints on extensions to the $\Lambda$CDM cosmological model from measurements of the $E$-mode polarization auto-power spectrum and the temperature-$E$-mode cross-power spectrum of the cosmic microwave background (CMB) made…

宇宙学与河外天体物理 · 物理学 2021-10-13 L. Balkenhol , D. Dutcher , P. A. R. Ade , Z. Ahmed , E. Anderes , A. J. Anderson , M. Archipley , J. S. Avva , K. Aylor , P. S. Barry , R. Basu Thakur , K. Benabed , A. N. Bender , B. A. Benson , F. Bianchini , L. E. Bleem , F. R. Bouchet , L. Bryant , K. Byrum , J. E. Carlstrom , F. W. Carter , T. W. Cecil , C. L. Chang , P. Chaubal , G. Chen , H. -M. Cho , T. -L. Chou , J. -F. Cliche , T. M. Crawford , A. Cukierman , C. Daley , T. de Haan , E. V. Denison , K. Dibert , J. Ding , M. A. Dobbs , W. Everett , C. Feng , K. R. Ferguson , A. Foster , J. Fu , S. Galli , A. E. Gambrel , R. W. Gardner , N. Goeckner-Wald , R. Gualtieri , S. Guns , N. Gupta , R. Guyser , N. W. Halverson , A. H. Harke-Hosemann , N. L. Harrington , J. W. Henning , G. C. Hilton , E. Hivon , G. P. Holder , W. L. Holzapfel , J. C. Hood , D. Howe , N. Huang , K. D. Irwin , O. B. Jeong , M. Jonas , A. Jones , T. S. Khaire , L. Knox , A. M. Kofman , M. Korman , D. L. Kubik , S. Kuhlmann , C. -L. Kuo , A. T. Lee , E. M. Leitch , A. E. Lowitz , C. Lu , S. S. Meyer , D. Michalik , M. Millea , J. Montgomery , A. Nadolski , T. Natoli , H. Nguyen , G. I. Noble , V. Novosad , Y. Omori , S. Padin , Z. Pan , P. Paschos , J. Pearson , C. M. Posada , K. Prabhu , W. Quan , A. Rahlin , C. L. Reichardt , D. Riebel , B. Riedel , M. Rouble , J. E. Ruhl , J. T. Sayre , E. Schiappucci , E. Shirokoff , G. Smecher , J. A. Sobrin , A. A. Stark , J. Stephen , K. T. Story , A. Suzuki , K. L. Thompson , B. Thorne , C. Tucker , C. Umilta , L. R. Vale , K. Vanderlinde , J. D. Vieira , G. Wang , N. Whitehorn , W. L. K. Wu , V. Yefremenko , K. W. Yoon , M. R. Young