2,363,058 research outputs found

    Thermalization through parton transport

    Full text link
    A radiative transport model is used to study kinetic equilibration during the early stage of a relativistic heavy ion collision. The parton system is found to be able to overcome expansion and move toward thermalization via parton collisions. Scaling behaviors show up in both the pressure anisotropy and the energy density evolutions. In particular, the pressure anisotropy evolution shows an approximate alpha_s scaling when radiative processes are included. It approaches an asymptotic time evolution on a time scale of 1 to 2 fm/c. The energy density evolution shows an asymptotic time evolution that decreases slower than the ideal hydro evolution. These observations indicate that partial thermalization can be achieved and viscosity is important for the evolution during the early longitudinal expansion stage of a relativistic heavy ion collision.Comment: Presented at the 10th International Conference on Nucleus-Nucleus Collisions (NN2009), Beijing, China, 16-21 Aug 200

    Decomposition theorem on matchable distributive lattices

    Full text link
    A distributive lattice structure M(G){\mathbf M}(G) has been established on the set of perfect matchings of a plane bipartite graph GG. We call a lattice {\em matchable distributive lattice} (simply MDL) if it is isomorphic to such a distributive lattice. It is natural to ask which lattices are MDLs. We show that if a plane bipartite graph GG is elementary, then M(G){\mathbf M}(G) is irreducible. Based on this result, a decomposition theorem on MDLs is obtained: a finite distributive lattice L\mathbf{L} is an MDL if and only if each factor in any cartesian product decomposition of L\mathbf{L} is an MDL. Two types of MDLs are presented: J(m×n)J(\mathbf{m}\times \mathbf{n}) and J(T)J(\mathbf{T}), where m×n\mathbf{m}\times \mathbf{n} denotes the cartesian product between mm-element chain and nn-element chain, and T\mathbf{T} is a poset implied by any orientation of a tree.Comment: 19 pages, 7 figure

    Structures of q-Deformed Currents

    Get PDF
    The non-perturbation and perturbation structures of the q-deformed probability currents are studied. According to two ways of realizing the q-deformed Heisenberg algebra by the undeformed operators, the perturbation structures of two q-deformed probability currents are explored in detail. Locally the structures of two perturbation q-deformed probability currents are different, one is explicitly potential dependent; the other is not. But their total contributions to the whole space are the same.Comment: 13. Physics Letters (in press

    Post processing of multimedia information - concepts, problems, and techniques

    Full text link
    Currently, most research work on multimedia information processing is focused on multimedia information storage and retrieval, especially indexing and content-based access of multimedia information. We consider multimedia information processing should include one more level-post-processing. Here &quot;post-processing&quot; means further processing of retrieved multimedia information, which includes fusion of multimedia information and reasoning with multimedia information to reach new conclusions. In this paper, the three levels of multimedia information processing storage, retrieval, and post-processing- are discussed. The concepts and problems of multimedia information post-processing are identified. Potential techniques that can be used in post-processing are suggested, By highlighting the problems in multimedia information post-processing, hopefully this paper will stimulate further research on this important but ignored topic.<br /
    corecore