We investigate the age distribution function P(t ,t) in prototypical coarsening processes. Here P(t ,t) is the probability density that in a time interval (0,t) a given site was last crossed by an interface in the coarsening process at time t . We determine P(t ,t) exactly in one dimension for the ~deterministic! two-velocity ballistic annihilation process and the ~stochastic! infinite-state Po...

We use x-ray photon correlation spectroscopy (XPCS) to probe the dynamics of colloidal particles in polycrystalline ice. During freezing, the dendritic ice morphology and rejection of particles from the ice created regions of high particle density, where some of the colloids were forced into contact and formed disordered aggregates. The particles in these high density regions underwent ballisti...

The problem of ballistic annihilation for a spatially homogeneous system is revisited within Boltzmann's kinetic theory in two and three dimensions. Analytical results are derived for the time evolution of the particle density for some isotropic discrete bimodal velocity modulus distributions. According to the allowed values of the velocity modulus, different behaviors are obtained: power law d...

We study a class of stochastic ballistic annihilation and coalescence models with a binary velocity distribution in one dimension. We obtain an exact solution for the density which reveals a universal phase diagram for the asymptotic density decay. By universal we mean that all models in the class are described by a single phase diagram spanned by two reduced parameters. The phase diagram revea...

This paper analyzes the properties of a two-field critical gradient model that couples a heat equation to an evolution equation for the turbulence intensity. It is shown that the dynamics of a perturbation is ballistic or diffusive depending on the shape of the pulse and also on the distance of the temperature gradient to the instability threshold. This dual character appears in the linear resp...

Theoretical bounds for estimating the ballistic coefficient of a ballistic object during the re-entry phase have been addressed. One essential characteristic of the vehicle trajectory is its deceleration when it reaches dense atmospheric layers. The intensity of the phenomenon is proportional to a scalar, called the ballistic coefficient. This leads to an highly nonlinear time-varying dynamic. ...

We show that the 5 GHz radio flux of transient ballistic jets in black hole binaries correlates well with the dimensionless black hole spin parameter a∗ estimated via the continuumfitting method. The data suggest that jet power scales either as the square of a∗ or the square of the angular velocity of the horizonΩH . This is the first direct evidence that jets are powered by black hole spin ene...