6 research outputs found

    Universal SSE algorithm for Heisenberg model and Bose Hubbard model with interaction

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    We propose universal SSE method for simulation of Heisenberg model with arbitrary spin and Bose Hubbard model with interaction. We report on the first calculations of soft-core bosons with interaction by the SSE method. Moreover we develop a simple procedure for increase efficiency of the algorithm. From calculation of integrated autocorrelation times we conclude that the method is efficient for both models and essentially eliminates the critical slowing down problem.Comment: 6 pages, 5 figure

    Unified Model for Dark Energy

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    A new model for the universe filled with a generalized Chaplygin fluid is considered which unitarily describes as a single vacuum entity both a quintessence scalar field and a cosmological constant, so unifying the notion of dark energy. While the evolution of the universe filled with such a fluid does not obviously contradict the present cosmic acceleration, the introduced single dark-energy component, for equations of state with characteristic parameter Ļ‰ā‰„āˆ’1\omega\geq -1, behaves like an usual quintessence fluid with constant equation of state at early high densities, and like a pure cosmological constant at late cosmological times.Comment: 5 pages, some misprints corrected, a comment on the initial equation of state inserted, one reference adde
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