相关论文: Post-Newtonian Sachs-Wolfe Effect
We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are allowed to be highly non-linear, and the…
In some scenarios, the peculiar gravitational potential of linear and mildly nonlinear structures depends on time and, as a result of this dependence, a late integrated Sachs-Wolfe effect appears. Here, an appropriate formalism is used…
The consequence of energy conservation in the flat Friedmannn-Robertson-Walker (FRW) cosmology is a strictly positive accelerating expansion. A mechanism is proposed for this expansion due to the effect of the attractive (negative)…
The cosmic microwave background (CMB) is sensitive to the recent phase of accelerated cosmic expansion through the late-time integrated Sachs-Wolfe (ISW) effect, which manifests as secondary temperature fluctuations on large angular scales.…
The observed apparent acceleration of the universe is usually attributed to negative pressure from a mysterious dark energy. This acceleration causes the gravitational potential to decay, heating or cooling photons travelling through crests…
The post-Newtonian (PN) perturbative framework has been successful in understanding the slow-motion, weak field limit of Einstein's theory of gravity on solar system scales, and for isolated astrophysical systems. The parameterized…
We give an improved formalism for calculating the evolution of density fluctuations and temperature perturbations in flat universes. Our equations are general enough to treat the perturbations in collisionless relics like massive neutrinos.…
Gravitational fluctuations along the line-of-sight from the surface of last scatter to the observer distort the microwave background in several related ways: The fluctuations deflect the photon path (gravitational lensing), the decay of the…
Light crossing dark domain walls that source a top form coupled to gauge Chern--Simons terms mixing visible and dark $U(1)$ gauge fields generically converts into dark photons. The effect is entirely localized on the wall and requires no…
We present detailed calculations of the magnification distribution, including both weak and strong lensing, using very recent solutions of the Dyer-Roeder (1973) equation for light propagation in a inhomogeneous universe with a cosmological…
Cartan torsion contribution to Sachs-Wolfe effect in the inflationary phase of the Universe is discussed.From the COBE data of the microwave anisotropy is possible to compute the spin-density in the Universe as $10^{16}$ mks units.The…
We analyze the thermal fluctuations of a free, conformally invariant, Maxwell quantum field (photon) interacting with a cosmological background spacetime, in the framework of quantum field theory in curved spacetimes and semiclassical and…
The Integrated Sachs-Wolfe effect is studied in non-standard cosmologies. By considering flat universes with a non-fluctuating dark energy component, it is shown how the quadrupole power can be suppressed by atypical evolution of the scale…
A theory of light transmission through a quantum well (QW) in a magnetic field perpendicular to the QW plane is developed. The light wave length is supposed comparable with the QW width. The formulas for reflection, absorption and…
The integrated Sachs-Wolfe (ISW) effect describes how photons are gravitationally redshifted, producing anisotropies in the Cosmic Microwave Background. We study the inverse problem and show that primordial gravitational perturbations, in…
How does inhomogeneity affect our interpretation of cosmological observations? It has long been wondered to what extent the observable properties of an inhomogeneous universe differ from those of a corresponding…
The quantum fluctuations of horizons in Robertson-Walker universes and in the Schwarzschild spacetime are discussed. The source of the metric fluctuations is taken to be quantum linear perturbations of the gravitational field. Lightcone…
We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy…
We study the redshift-space fluctuations induced by a stochastic gravitational wave background (SGWB) via the Sachs-Wolfe effect. The redshift-space fluctuations can be encapsulated in a line-of-sight integral that is useful for studying…
The photon density operator function is used to calculate light beam propagation through turbulent atmosphere. A kinetic equation for the photon distribution function is derived and solved using the method of characteristics. Optical wave…