We study the dependence of column densities derived from absorption lines on the spatial distribution of the ions in an absorber. In particular, we investigate four varieties of coverage by the absorber of the background source: the familiar homogeneous partial coverage (HPC), and three functional forms that parameterize inhomogeneous coverage: a powerlaw, an ellipse quandrant, and a Gaussian d...

Measurement of fluorescent lifetimes of dye-tagged DNA molecules reveal the existence of different conformations. Conformational fluctuations observed by fluorescence correlation spectroscopy give rise to a relaxation behavior that is described by "stretched" exponentials and indicates the presence of a distribution of transition rates between two conformations. Whether this is an inhomogeneous...

Theoretical consideration of the optical response of nascent free electrons in the process of laser filamentation reveals that the initial microscopically inhomogeneous charge distribution causes a transient electromagnetic response of the medium that differs drastically from that of a homogeneous plasma with the same degree of ionization. An analytical model, describing the forced oscillations...

The sedimentation of an initially inhomogeneous distribution of hard-sphere colloids confined in a slit is simulated using the multi-particle collision dynamics scheme which takes into account hydrodynamic interactions mediated by the solvent. This system is an example for soft matter driven out of equilibrium where various length and time scales are involved. The initial laterally homogeneous ...

The numerical dispersion relation governing the propagation of homogeneous plane waves in a finite-difference time-domain (FDTD) grid is well known. However, homogeneous plane waves, by themselves, do not form a complete basis set capable of representing all valid field distributions. A complete basis set is obtained by including inhomogeneous waves where, in the physical world, constant phase ...

In 1982, Tsallis derived a formula which proposed an exact value of 0.522372078 . . . for the bond percolation threshold of the kagome lattice. We use the substitution method, which is based on stochastic ordering, to compare the probability distribution of connections in the homogeneous bond percolation model on the kagome lattice to those of an exactly-solved inhomogeneous bond percolation mo...

We investigate the role of global mixing in epidemic processes. We first construct a simplified model of the SIR epidemic using a realistic population distribution. Using this model, we examine possible mechanisms for destruction of spatial correlations, in an attempt to produce correlation curves similar to those reported recently for real epidemiological data. We find that introduction of a l...