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相关论文: CMB anisotropy induced by tachyonic perturbations …

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We investigate the consequences of an imperfect dark energy component on the large scale structure. A phenomenological three parameter fluid description is used to study the effect of dark energy on the cosmic microwave background radiation…

天体物理学 · 物理学 2009-11-13 Tomi Koivisto , David F. Mota

Anisotropy in the speed of light that has been constrained by Michelson-Morley-type experiments also generates anisotropy in the Coulomb interactions. This anisotropy can manifest itself as an energy anisotropy in nuclear and atomic…

核理论 · 物理学 2017-04-12 V. V. Flambaum , M. V. Romalis

Several intriguing phenomena, unlikely within the standard inflationary cosmology, were reported in the cosmic microwave background (CMB) data from WMAP and appear to be uncorrelated. Two of these phenomena, termed CMB anomalies, are…

宇宙学与河外天体物理 · 物理学 2009-12-30 Armando Bernui

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

Primordial magnetic fields present since before the epoch of matter-radiation equality have an effect on the anisotropies of the cosmic microwave background. The CMB anisotropies due to scalar perturbations are calculated in the gauge…

宇宙学与河外天体物理 · 物理学 2011-02-02 Kerstin E. Kunze

We determine the full C_l spectra and correlation functions of the temperature and polarization anisotropies in the CMB, generated by a source modeled by the large N limit of spontaneously broken global O(N)-theories. We point out a problem…

宇宙学与河外天体物理 · 物理学 2015-06-17 Elisa Fenu , Daniel G. Figueroa , Ruth Durrer , Juan Garcia-Bellido , Martin Kunz

We exhibit a tachyonic mode in a linearized analysis of perturbations of large anti-de Sitter Reissner-Nordstrom black holes in four dimensions. In the large black hole limit, and up to a 0.7% discrepancy which is probably round-off error…

高能物理 - 理论 · 物理学 2007-05-23 Steven S. Gubser , Indrajit Mitra

Inspired by a dipole asymmetric template for the CMB temperature map in the primordial scalar fluctuations observed by Planck at a large scale, we examine the contribution of a similar template for power asymmetry in modifying the linear…

广义相对论与量子宇宙学 · 物理学 2023-08-01 Jafar Khodagholizadeh , Rohoollah Mohammadi , S. M. S. Movahed

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis…

天体物理学 · 物理学 2009-11-10 Fabio Giovi , Carlo Baccigalupi , Francesca Perrotta

The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy. Modifications of the Friedmann equation…

宇宙学与河外天体物理 · 物理学 2015-05-28 Jeremy Mould

We give a brief review of the known effects of a dynamical vacuum cosmological component, the dark energy, on the anisotropies of the cosmic microwave background (CMB). We distinguish between a "classic" class of observables, used so far to…

天体物理学 · 物理学 2009-09-01 Carlo Baccigalupi , Viviana Acquaviva

If the dark energy equation of state is anisotropic, the expansion rate of the universe becomes direction-dependent at late times. We show that such models are not only cosmologically viable but that they could explain some of the observed…

天体物理学 · 物理学 2010-11-11 Tomi Koivisto , David F. Mota

For dynamical dark energy with the barotropic equation of state we determine the mean values of parameters and their confidence ranges together with other cosmological parameters on the basis of different combined datasets. The used…

宇宙学与河外天体物理 · 物理学 2018-11-13 O. Sergijenko

We present local extrema studies of two models that introduce a preferred direction into the observed cosmic microwave background (CMB) temperature field. In particular, we make a frequentist comparison of the one- and two-point statistics…

宇宙学与河外天体物理 · 物理学 2014-11-20 Zhen Hou , A. J. Banday , K. M. Gorski , N. E. Groeneboom , H. K. Eriksen

We study a novel interacting dark energy $-$ dark matter scenario where the anisotropic stress of the large scale inhomogeneities is considered. The dark energy has a constant equation of state and the interaction model produces stable…

宇宙学与河外天体物理 · 物理学 2018-12-21 Weiqiang Yang , Supriya Pan , Lixin Xu , David F. Mota

The power spectrum of temperature anisotropies induced by hot intracluster gas on the cosmic background radiation is calculated. For low multipoles it remains constant while at multipoles above $l>2000$ it is exponentially damped. The shape…

天体物理学 · 物理学 2009-10-31 F. Atrio Barandela , J. P. Muecket

We present current and future constraints on equations of state for dark sector perturbations. The equations of state considered are those corresponding to a generalized scalar field model and time-diffeomorphism invariant $L(g)$ theories…

宇宙学与河外天体物理 · 物理学 2015-06-29 Richard A. Battye , Adam Moss , Jonathan A. Pearson

Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly…

高能物理 - 唯象学 · 物理学 2015-06-22 Guo-Chin Liu , Kin-Wang Ng , I-Chin Wang

Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from…

宇宙学与河外天体物理 · 物理学 2014-07-29 Maresuke Shiraishi , David F. Mota , Angelo Ricciardone , Frederico Arroja

According to inflationary cosmology, the CMB anisotropy gives an opportunity to test predictions of new physics hypotheses. The initial state of quantum fluctuations is one of the important options at high energy scale, as it can affect…

高能物理 - 理论 · 物理学 2016-04-01 A. Sojasi , M. Mohsenzadeh , E. Yusofi