16,262 research outputs found
13-Moment System with Global Hyperbolicity for Quantum Gas
We point out that the quantum Grad's 13-moment system [R. Yano, Physica A:
Statistical Mechanics and its Applications, 416:231-241, 2014] is lack of
global hyperbolicity, and even worse, the thermodynamic equilibrium is not an
interior point of the hyperbolicity region of the system. To remedy this
problem, by fully considering Grad's expansion, we split the expansion into the
equilibrium part and the non-equilibrium part, and propose a regularization for
the system with the help of the new theory developed in [Z. Cai et al., SIAM J.
Appl. Math., 75(5):2001-2023, 2015, Y. Fan, J. Stat. Phys., 161(4), 2015]. This
provides us a new model which is hyperbolic for all admissible thermodynamic
states, and meanwhile preserves the approximate accuracy of the original
system. It should be noted that this procedure is not a trivial application of
the theory in [Z. Cai et al., SIAM J. Appl. Math., 75(5):2001-2023, 2015, Y.
Fan, J. Stat. Phys., 161(4), 2015].Comment: 23 pages and 12 figure
Phase transitions in Ising model induced by weight redistribution on weighted regular networks
In order to investigate the role of the weight in weighted networks, the
collective behavior of the Ising system on weighted regular networks is studied
by numerical simulation. In our model, the coupling strength between spins is
inversely proportional to the corresponding weighted shortest distance.
Disordering link weights can effectively affect the process of phase transition
even though the underlying binary topological structure remains unchanged.
Specifically, based on regular networks with homogeneous weights initially,
randomly disordering link weights will change the critical temperature of phase
transition. The results suggest that the redistribution of link weights may
provide an additional approach to optimize the dynamical behaviors of the
system.Comment: 6 pages, 5 figure
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