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相关论文: Discrete spectral shift in an anisotropic universe

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This article details the computation of the two-point correlators of the convergence, $E$- and $B$-modes of the cosmic shear induced by the weak-lensing by large scale structure assuming that the background spacetime is spatially…

宇宙学与河外天体物理 · 物理学 2017-01-13 Cyril Pitrou , Thiago S. Pereira , Jean-Philippe Uzan

Astronomical observations showed that there may exist a bulk flow with peculiar velocities in the universe, which contradicts with the (\Lambda)CDM model. The bulk flow reveals that the observational universe is anisotropic at large scales.…

宇宙学与河外天体物理 · 物理学 2013-06-07 Zhe Chang , Ming-Hua Li , Sai Wang

We study particle creation phenomenon by the Coulomb potential of an external electric field in the presence of a gravitational field of a static cosmic string. For that, the generalized Klein-Gordon and Dirac equations are solved, and by…

广义相对论与量子宇宙学 · 物理学 2023-07-06 B. Belbaki , A. Bounames

Cosmic acceleration is explained quantitatively, purely in general relativity, as an apparent effect due to quasilocal gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe.…

广义相对论与量子宇宙学 · 物理学 2008-11-26 David L. Wiltshire

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

广义相对论与量子宇宙学 · 物理学 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray

We investigate the behaviour of the skewness parameters for an anisotropic universe in the framework of General Relativity. Non interacting dark energy is considered in presence of electromagnetic field. A time varying deceleration…

综合物理 · 物理学 2022-07-19 B. Mishra , Pratik P Ray , S. K. Tripathy , Kazuharu Bamba

In this study, we have explored a scalar field cosmological model in the axially symmetric Bianchi type-I universe. In this study, our aim is to constrain the scalar field dark energy model in an anisotropic background. For this purpose,…

广义相对论与量子宇宙学 · 物理学 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure. In this paper we develop and test a new statistic based on anisotropies in the…

天体物理学 · 物理学 2009-11-13 Will J Percival , Martin White

The anisotropy of the redshift space bispectrum contains a wealth of cosmological information. This anisotropy depends on the orientation of three vectors ${\bf k_1,k_2,k_3}$ with respect to the line of sight. Here we have decomposed the…

宇宙学与河外天体物理 · 物理学 2020-02-12 Somnath Bharadwaj , Arindam Mazumdar , Debanjan Sarkar

Here we consider a scenario in which dark energy is associated with the apparent area of a surface in the early universe. In order to resemble the cosmological constant at late times, this hypothetical reference scale should maintain an…

天体物理学 · 物理学 2010-10-27 Fergus Simpson

We explore the consequences of loop quantum cosmology (inverse-volume corrections) in the spectrum of the gravitational waves using the method of the Bogoliubov coefficients. These corrections are taken into account at the background level…

广义相对论与量子宇宙学 · 物理学 2014-01-22 Joao Morais , Mariam Bouhmadi-Lopez , Alfredo B. Henriques

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

A local current of particle density for scalar fields in curved background is constructed. The current depends on the choice of a two-point function. There is a choice that leads to local non-conservation of the current in a time-dependent…

广义相对论与量子宇宙学 · 物理学 2014-11-17 H. Nikolic

The general solution of Einstein's gravity equation in $D$ dimensions for an anisotropic and spherically symmetric matter distribution is calculated in a bulk with position dependent cosmological constant. Results for $n$ concentric…

广义相对论与量子宇宙学 · 物理学 2013-03-01 I. C. Jardim , R. R. Landim , G. Alencar , R. N. Costa Filho

The scalar particle production through a scalar field non-minimally coupled with geometry is investigated in the context of a spatially homogeneous and isotropic universe. In this paper, in order to study the evolution of particle…

广义相对论与量子宇宙学 · 物理学 2018-05-09 Hao Yu , Wen-Di Guo , Ke Yang , Yu-Xiao Liu

We consider a perfectly homogeneous, isotropic and spatially flat universe which undergoes a sudden phase transition producing topological defects. We assume that these defects form a coherent network which scales like the background…

天体物理学 · 物理学 2007-05-23 Jean-Philippe Uzan , Nathalie Deruelle , Alain Riazuelo

We propose a new scenario for the early universe where there is a smooth transition between an early de Sitter-like phase and a radiation dominated era. In this model, the matter content is modelled by a new type of generalised Chaplygin…

宇宙学与河外天体物理 · 物理学 2010-03-16 Mariam Bouhmadi-Lopez , Pedro Frazao , Alfredo B. Henriques

We report results on an ``one-way light path'' laser diffraction experiment as a function of the laser beam alignment relative to the Earth's velocity vector obtained by COBE measurements of the Doppler shift in the cosmic microwave…

天体物理学 · 物理学 2007-05-23 C. E. Navia , C. R. A. Augusto

The arrival directions of Galactic cosmic rays exhibit anisotropies up to the level of one per-mille over various angular scales. Recent observations of TeV-PeV cosmic rays show that the dipole anisotropy has a strong energy dependence with…

高能天体物理现象 · 物理学 2019-05-22 Markus Ahlers

There is tentative evidence for a mismatch between the rest frames of matter and the cosmic microwave background, the "quasar dipole anomaly". We consider such a dipole in tilted anisotropic models, for a range of scenarios and sources:…

宇宙学与河外天体物理 · 物理学 2025-12-04 Alicia Martín , Constantinos Skordis , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira , Tariq Yasin