Gutzwiller's trace formula allows interpretation of the density of states of a classically chaotic quantum system in terms of classical periodic orbits. It diverges when periodic orbits undergo bifurcations and must be replaced with a uniform approximation in the vicinity of the bifurcations. As a characteristic feature, these approximations require the inclusion of complex ``ghost orbits''. By...

We study three type of star products in SFT: the ghosts, the twisted ghosts and the matter. We find that their Neumann coefficients are related to each other in a compact way which includes the Gross-Jevicki relation between matter and ghost sector: we explicity show that the same relation, with a minus sign, holds for the twisted and nontwisted ghost (which are different but define the same so...

Ghost images are obtained by correlating the output of a single-pixel (bucket) photodetector—which collects light that has been transmitted through or reflected from an object—with the output from a high spatial-resolution scanning photodetector or photodetector array whose illumination has not interacted with that object. The term “ghost image” is apt because neither detector’s output alone ca...

Abstract The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and three-gluon vertex is investigated for both the covariant Landau and the non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a unique infrared exponent in the d = 4 Landau gauge, while in the d = 3 + 1 Coulomb gauge we find two different infrared exponents. We also show that a finite dress...

Since its first experimental demonstration, ghost imaging has attracted a great deal of attention due to interests in its fundamental nature and its potential applications. In terms of applications, the most interesting and useful feature, perhaps, is the turbulence insensitivity of thermal light ghost imaging, i.e., atmospheric turbulence would not have any influence on the ghost images of sun...

We show that there is (p − 1)(p − 1) dimensional semi-relative BRST cohomology at each non-positive ghost number in the (p, p) minimal conformal field theory coupled to two dimensional quantum gravity. These closed string states are related to currents and symmetry charges of ‘exotic’ ghost number. We investigate the symmetry structure generated by the most conventional currents (those of vanis...

I study large-eddy simulation of the atmospheric boundary layer on block structured non-uniform grids. This type of grid, which includes nested grids, is very popular in atmospheric science as a way of concentrating computational power. Large-eddy simulation is a widely used method of approximately solving incompressible Navier-Stokes in turbulent regimes, including the atmospheric boundary lay...

Gutzwiller's trace formula allows interpreting the density of states of a classically chaotic quantum system in terms of classical periodic orbits. It diverges when periodic orbits undergo bifurcations, and must be replaced with a uniform approximation in the vicinity of the bifurcations. As a characteristic feature, these approximations require the inclusion of complex " ghost orbits ". By stu...