8,793 research outputs found
Chiral gauge theories on the lattice and restoration of gauge symmetry
We investigate a proposal for the construction of models with chiral fermions
on the lattice using staggered fermions. In this approach the gauge invariance
is broken by the coupling of the staggered fermions to the gauge fields. We aim
at a dynamical restoration of the gauge invariance in the full quantum model.
If the gauge symmetry breaking (SB) is not too severe, this procedure could
lead in the continuum limit to the desired gauge invariant chiral gauge theory.Comment: 3 pages, 2 postscript files appended (uuencoded), contribution to
Lattice'93, ITFA 93-32, UCSD/PTH 93-3
Finite Temperature Simulations from Quantum Field Dynamics?
We describe a Hartree ensemble method to approximately solve the Heisenberg
equations for the \phi^4 model in 1+1 dimensions. We compute the energies and
number densities of the quantum particles described by the \phi field and find
that the particles initially thermalize with a Bose-Einstein distribution for
the particle density. Gradually, however, the distribution changes towards
classical equipartition. Using suitable initial conditions quantum
thermalization is achieved much faster than the onset of this undesirable
equipartition. We also show how the numerical efficiency of our method can be
significantly improved.Comment: Lattice 2000 (Finite Temperature), 4 pages, 5 figures; title
correcte
Structural Analysis of Boolean Equation Systems
We analyse the problem of solving Boolean equation systems through the use of
structure graphs. The latter are obtained through an elegant set of
Plotkin-style deduction rules. Our main contribution is that we show that
equation systems with bisimilar structure graphs have the same solution. We
show that our work conservatively extends earlier work, conducted by Keiren and
Willemse, in which dependency graphs were used to analyse a subclass of Boolean
equation systems, viz., equation systems in standard recursive form. We
illustrate our approach by a small example, demonstrating the effect of
simplifying an equation system through minimisation of its structure graph
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