相关论文: Looking for $\Lambda$ with the Rees-Sciama Effect
Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (``cosmic variance'') with which anisotropies can determine the amplitude of primordial…
Observational cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation. The transition to precision cosmology…
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…
With the new generation of instruments for Cosmic Microwave Background (CMB) observations aiming at an accuracy level of a few percent in the measurement of the angular power spectrum of the anisotropies, the study of the contributions due…
A new method arising from a gauge-theoretic approach to general relativity is applied to the formation of clusters in an expanding universe. The three cosmological models (Omega_0=1, Omega_Lambda=0), (Omega_0=0.3, Omega_Lambda=0.7),…
We present a new limit on the cosmological constant based on the absence of correlations between the cosmic microwave background (CMB) and the distribution of distant radio sources. In the cosmological constant-cold dark matter models…
Gravitational lensing, caused by matter perturbations along the line-of-sight to the last scattering surface, can modify the shape of the cosmic microwave background (CMB) anisotropy power spectrum. We discuss the detectability of lensing…
We study the cosmic microwave background (CMB) anisotropy due to spherically symmetric nonlinear structures in flat universes with dust and a cosmological constant. By modeling a time-evolving spherical compensated void/lump by…
Cosmic Microwave Background (CMB) anisotropies that result from quantum fluctuations during inflation are explored and the impact of their ``cosmic variance'' on the ability to use existing data to probe inflationary models is studied. We…
Gravitational lensing of the cosmic microwave background (CMB), a long-standing prediction of the standard cosmolgical model, is ultimately expected to be an important source of cosmological information, but first detection has not been…
We consider the weak lensing effect induced by linear cosmological perturbations on the cosmic microwave background (CMB) polarization anisotropies. We find that the amplitude of the lensing peak in the BB mode power spectrum is a faithful…
We compute the cosmic microwave background (CMB) anisotropy in a low-density, flat, cosmological constant, cold dark matter model which is normalized to the two-year COBE DMR sky map. Although conclusions regarding model viability must…
Observational searches for large-scale vorticity modes in the late time Universe are underexplored. Within the standard $\Lambda$CDM model, this is well motivated given the observed properties of the cosmic microwave background (CMB).…
Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only…
The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…
The advent of high resolution cosmic microwave background (CMB) experiments now allows studies on the temperature fluctuations at scales corresponding to few arcminutes and below. Though the reported excess power at $\ell \sim 2000 - 6000$…
The cosmic microwave background (CMB) offers a unique window into the early universe, providing insights into cosmological parameters like the Hubble constant. Recent precise measurements of the CMB by experiments like Planck seem to point…
There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…
The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…
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…