We study the Cosmic Microwave Background (CMB) anisotropies produced by cosinetype quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations with scale invariant spectrum, we obtain a stringent constraint on the model parameters using the CMB data from COBE, BOOMERanG and MAXIMA. Furthermore, it is...

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations with scale invariant spectrum, we obtain a stringent constraint on the model parameters using the CMB data from COBE, BOOMERanG and MAXIMA. Furthermore, it i...

In this work we present a theoretical and experimental study of the response of a lossless polarizer to a signal beam with a time-varying state of polarization. By lossless polarizer we mean a nonlinear conservative medium (e.g., an optical fiber) which is counter-pumped by an intense and fully polarized pump beam. Such medium transforms input uniform or random distributions of the state of pol...

During resting conditions the brain remains functionally and metabolically active. One manifestation of this activity that has become an important research tool is spontaneous fluctuations in the blood oxygen level-dependent (BOLD) signal of functional magnetic resonance imaging (fMRI). The identification of correlation patterns in these spontaneous fluctuations has been termed resting state fu...

We report muon spin relaxation and inelastic neutron measurements on the Heusler system YbPd2Sn. Localised anisotropic and quasi-elastic Yb magnetic fluctuations are observed below T = 150K. Both μSR and neutron data indicate a slowing-down of the spin-fluctuations, upon lowering the temperature, similar to that observed in Kondo lattices. The temperature dependence of the quasi-elastic neutron...

Comparison of the COBE observed quadrupole anisotropy with that predicted in adiabatic CDM models suggests that much of the observed signal may be due to long wavelength gravitational waves. In inflationary models this requires the generation of tensor fluctuations to be at least comparable to scalar density fluctuations. This is feasible, but depends sensitively on the inflaton potential. Alte...

Transient elevations of intracellular Ca2+ levels play critical roles in neuronal development, but such elevations have not been demonstrated in migrating neurons. Here, we show that the amplitude and frequency components of Ca2+ fluctuations are correlated positively with the rate of granule cell movement in cerebellar microexplant cultures. Moreover, depression of the amplitude and frequency ...

Density fluctuations resulting from spinodal decomposition in a nonequilibrium first-order chiral phase transition are explored. We show that such instabilities generate divergent fluctuations of conserved charges along the isothermal spinodal lines appearing in the coexistence region. Thus, divergent density fluctuations could be a signal not only for the critical end point but also for the fi...

We model the impact of atmospheric turbulence-induced phase and amplitude fluctuations on free-space optical links using synchronous detection. We derive exact expressions for the probability density function of the signal-to-noise ratio in the presence of turbulence. We consider the effects of log-normal amplitude fluctuations and Gaussian phase fluctuations, in addition to local oscillator sh...

Using the mitochondrial membrane potential (DeltaPsi(m))-sensitive fluorescent dyes 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide (JC-1) and tetramethylrhodamine methyl ester (TMRM), we have observed spontaneous changes in the DeltaPsi(m) of cultured forebrain neurons. These fluctuations in DeltaPsi(m) appear to represent partial, transient depolarizations of indivi...