303 research outputs found

    Understanding human behaviour in fire: Validation of the Use of Serious Gaming for Research into Fire Safety Psychonomics

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    Helsloot, I. [Promotor]Vries, B. de [Copromotor

    Chapman-Enskog expansion of the Boltzmann equation and its diagrammatic interpretation

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    We perform a Chapman-Enskog expansion of the Boltzmann equation keeping up to quadratic contributions. We obtain a generalized nonlinear Kubo formula, and a set of integral equations which resum ladder and extended ladder diagrams. We show that these two equations have exactly the same structure, and thus provide a diagrammatic interpretation of the Chapman-Enskog expansion of the Boltzmann equation, up to quadratic order.Comment: 5 pages, 2 figures in eps, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL http://ismd31.ccnu.edu.cn

    A Slavnov-Taylor identity and equality of damping rates for static transverse and longitudinal gluons in hot QCD

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    A Slavnov-Taylor identity is derived for the gluon polarization tensor in hot QCD. We evaluate its implications for damping of gluonic modes in the plasma. Applying the identity to next to the leading order in hard-thermal-loop resummed perturbation theory, we derive the expected equality of damping rates for static transverse and longitudinal (soft) gluons. This is of interest also in view of deviating recent reports of γt(p=0)≠γl(p=0)\gamma_t(p=0)\neq\gamma_l(p=0) based on a direct calculation of γl(p=0)\gamma_l(p=0).Comment: 13 pages, 1 figure, LaTe

    Spontaneous Scale Symmetry Breaking in 2+1-Dimensional QED at Both Zero and Finite Temperature

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    A complete analysis of dynamical scale symmetry breaking in 2+1-dimensional QED at both zero and finite temperature is presented by looking at solutions to the Schwinger-Dyson equation. In different kinetic energy regimes we use various numerical and analytic techniques (including an expansion in large flavour number). It is confirmed that, contrary to the case of 3+1 dimensions, there is no dynamical scale symmetry breaking at zero temperature, despite the fact that chiral symmetry breaking can occur dynamically. At finite temperature, such breaking of scale symmetry may take place.Comment: 12 pages, no figures, uses RevTeX4-bet

    Four-Point Spectral Functions and Ward Identities in Hot QED

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    We derive spectral representations for the different components of the 4-point function at finite temperature in the real time formalism in terms of five real spectral densities. We explicitly calculate all these functions in QED in the hard thermal loop approximation. The Ward identities obeyed by the 1-loop 3- and 4-point functions in real time and their spectral functions are derived. We compare our results with those derived previously in the imaginary-time formalism for retarded functions in hot QCD, and we discuss the generalization of our results to non-equilibrium situations.Comment: 16 pages in Revtex with 3 figures, dense version, a typo correcte
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