The diffractive dissociation of virtual photons, γ * p → Xp, has been studied in ep interactions at HERA with the H1 and ZEUS detectors. The data are presented in terms of the diffractive structure function F D 2 and of the diffractive cross sections dσ/dt and dσ/dMX. The t-dependence of the cross section is measured. The Pomeron intercepts extracted from diffractive and inclusive ep interactio...

Pure lattice SU(2) Yang-Mills theory in five dimensions is considered, where an extra dimension is compactified on a circle. Monte-Carlo simulations indicate that the theory possesses a continuum limit with a non-vanishing string tension if the compactification radius is smaller than a certain value RM which is O(1/10) of the inverse of the square root of the string tension. We verify non-pertu...

The discrete-ordinates method is used to develop a solution to a class of non-grey problems in the theory of radiative transfer. The model considered allows for scattering with complete frequency redistribution (completely non-coherent scattering) and continuum absorption. In addition to a general formulation for semi-in"nite and "nite plane-parallel media, speci"c computations, for both the Do...

-The continuum non-classical nucleation theory of Cahn and Hilliard for isostructural decomposition has been extended to the case in which the precipitate and matrix not only have different compositions, but also have different structures. The particular example of precipitation of ordered intermetallics from a disordered matrix is considered. It is found that a critical nucleus consists of flu...

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 705 2 Basic concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 705 3 The Jordan Curve Theorem and the concept of a curve . . . . . . . . . . . . . . . . . 707 4 Local connectedness; plane continua.. . . . . ....

We present a continuum theory of fracture which describes the fast propagation of cracks. The theory overcomes the usual problem of a finite time cusp singularity of the Grinfeld instability by the inclusion of elastodynamic effects which restore the selection of the steady state tip radius and velocity. Two different numerical approaches are presented to solve this problem. A sharp interface a...

One of the most well known examples of phenomena that introduces and motivates the study of continuum percolation is the process of the ground getting wet during a period of rain. At each point hit by a raindrop, one sees a circular wet patch. Right after the rain begins to fall what one sees is a small wet region inside a large dry region. At some instant, so many raindrops have hit the ground...

In 1961 Gilbert defined a model of continuum percolation in which points are placed in the plane according to a Poisson process of density one, and two are joined if one lies within a disc of area A about the other. We prove some good bounds on the critical area Ac for percolation in this model. The proof is in two parts: first we give a rigorous reduction of the problem to a finite problem, an...

Regularized continuum gauge theory coupled to quadratic matter simplifies significantly on integration of the matter fields. As an illustration, we discuss in some detail the resulting non-Grassmann formulation of regularized gauge theory with Dirac fermions.

We investigate the field theory of strings having as a target space an arbitrary discrete one-dimensional manifold. The existence of the continuum limit is guaranteed if the target space is a Dynkin diagram of a simply laced Lie algebra or its affine extension. In this case the theory can be mapped onto the theory of strings embedded in the infinite discrete line ZZ which is the target space of...