Related papers: Time Dilation and Quasar Variability
The well-known bluer-when-brighter trend observed in quasar variability is a signature of the complex processes in the accretion disk, and can be a probe of the quasar variability mechanism. Using a sample of 604 variable quasars with…
If spacetime undergoes quantum fluctuations, an electromagnetic wavefront will acquire uncertainties in direction as well as phase as it propagates through spacetime. These uncertainties can show up in interferometric observations of…
Space-time variation of fundamental physical constants in expanding Universe is predicted by a number of popular models. The masses of second generation quarks are larger than first generation quark masses by several orders of magnitude,…
Calculation of the Dirac hydrogen atom spectrum in the framework of dynamical fine structure constant (alpha) variability discloses a small departure in the laboratory from Sommerfeld's formula for the fine structure shifts, possibly…
We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent than the one found in the…
Broad Absorption Line (BAL) trough variability is predominantly due to cloud motion transverse to our line of sight. The rate at which the variability occurs indicates the velocity of the cloud, which can provide constraints on the cloud's…
It is considered that quasars evolve into normal galaxies by means of expansion of matter. The order of magnitude of the expansion velocity can be estimated. The Doppler shift caused by such expansion explains the supposed variation of the…
The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$\alpha$ absorption lines), that might be directly observed by future ultra…
We study the observed small deviations of high-redshift absorption spectra that are interpreted as a possible evidence for a variable fine structure constant. On the contrary, we claim that the effect could be completely attributed to the…
Flickering is a ubiquitous phenomenon in cataclysmic variables (CVs). Although the underlying light source is one of the main contributors to the optical radiation, the mechanism leading to flickering is not understood as yet. The present…
The possibility is examined that the masses of the light quarks $u$ and $d$ have varied over the course of the universe's evolution. Such a variation would have an effect on axion cosmology, and can be the basis of a solution of the…
We review recent activity searching for variations in the fundamental constants of nature in quasar absorption spectra and in the laboratory. While research in this direction has been ongoing for many decades, the topic has recently been…
This paper is concerned with the effect of parameter fluctuations with a characteristic waiting time in coupled R\"{o}ssler oscillators. We show that the averaged error in synchronization that is introduced due to a fluctuating parameter is…
The gravitational field of a galaxy can act as a lens and deflect the light emitted by a more distant object such as a quasar. Strong gravitational lensing causes multiple images of the same quasar to appear in the sky. Since the light in…
The physics of low-energy quantum systems is usually studied without explicit consideration of the background spacetime. Phenomena inherent to quantum theory on curved space-time, such as Hawking radiation, are typically assumed to be only…
The majority of quasars are weak in their radio emission, with flux densities comparable to those in the optical, and energies far lower. A small fraction, about 10%, are hundreds to thousands of times stronger in the radio. Conventional…
We consider some implications of the mass defect on the frequency of atomic transitions. We have found that some well-known frequency shifts (gravitational shift and motion-induced shifts such as: quadratic Doppler and micromotion shifts)…
We derive the time dilation formula for charged quantum clocks in electromagnetic fields. As a concrete example of non-inertial motion, we consider a cyclotron motion in a uniform magnetic field. Applying the time dilation formula to…
A dynamical effect of coherent backscattering is predicted theoretically and supported by computer simulations: The distribution of single-mode delay times of waves reflected by a disordered waveguide depends on whether the incident and…
The large observed redshift of quasars has suggested large cosmological distances and a corresponding enormous energy output to explain the brightness or luminosity as seen at earth. Alternative or complementary sources of redshift have not…