10 research outputs found
A Novel Approach to Discontinuous Bond Percolation Transition
We introduce a bond percolation procedure on a -dimensional lattice where
two neighbouring sites are connected by channels, each operated by valves
at both ends. Out of a total of , randomly chosen valves are open at
every site. A bond is said to connect two sites if there is at least one
channel between them, which has open valves at both ends. We show analytically
that in all spatial dimensions, this system undergoes a discontinuous
percolation transition in the limit when
crosses a threshold. It must be emphasized
that, in contrast to the ordinary percolation models, here the transition
occurs even in one dimensional systems, albeit discontinuously. We also show
that a special kind of discontinuous percolation occurs only in one dimension
when depends on the system size.Comment: 6 pages, 6 eps figure
Particle Ordering in Zero Range Process : Exact spatial correlations of the corresponding exclusion models
A one dimensional exclusion process is introduced where particles hop to a
neighbouring vacant site with a rate that depends on the size of the block they
belong to. This model is equivalent to a zero range process (ZRP) and shares
the same steady state distribution. However positional ordering is lost in this
mapping and spatial correlations which depend on position indices can not be
calculated directly from the ZRP equivalence. We devise a method to calculate
these correlations and illustrate it by reproducing certain known results.
Unexplored correlations in some other model systems are also investigated. This
method can be generically used to find exact correlations of one dimensional
exclusion processes which has ZRP correspondence.Comment: 9 pages, 1 eps figur
Social Media, Gender and the Mediatisation of War: Exploring the German Armed Forcesâ Visual Representation of the Afghanistan Operation on Facebook
Studies on the mediatisation of war point to attempts of governments to regulate the visual perspective of their involvements in armed conflict â the most notable example being the practice of âembedded reportingâ in Iraq and Afghanistan. This paper focuses on a different strategy of visual meaning-making, namely, the publication of images on social media by armed forces themselves. Specifically, we argue that the mediatisation of war literature could profit from an increased engagement with feminist research, both within Critical Security/Critical Military Studies and within Science and Technology Studies that highlight the close connection between masculinity, technology and control. The article examines the German military mission in Afghanistan as represented on the German armed forcesâ official Facebook page. Germany constitutes an interesting, and largely neglected, case for the growing literature on the mediatisation of war: its strong antimilitarist political culture makes the representation of war particularly delicate. The paper examines specific representational patterns of Germanyâs involvement in Afghanistan and discusses the implications which arise from what is placed inside the frame of visibility and what remains out of its view
Short-Time Behavior and Criticality of Driven Lattice Gases
The nonequilibrium short-time critical behaviors of driven and undriven lattice gases are investigated via Monte Carlo simulations in two spatial dimensions starting from a fully disordered initial configuration. In particular, we study the time evolution of suitably defined order parameters, which account for the strong anisotropy introduced by the homogeneous drive. We demonstrate that, at short times, the dynamics of all these models is unexpectedly described by an effective continuum theory in which transverse fluctuations, i.e., fluctuations averaged along the drive, are Gaussian, irrespective of this being actually the case in the stationary state. Strong numerical evidence is provided, in remarkable agreement with that theory, both for the driven and undriven lattice gases, which therefore turn out to display the same short-time dynamics