7,190 research outputs found

    Extracting and Stabilizing the Unstable State of Hysteresis Loop

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    A novel perturbation method for the stabilization of unstable intermediate states of hysteresis loop (i.e. S-shaped curve) is proposed. This method only needs output signals of the system to construct the perturbation form without delay-coordinate embedding technique, it is more practical for real-world systems. Stabilizing and tracking the unstable intermediate branch are demonstrated through the examples of a bistable laser system and delay feedback system. All the numerical results are obtained by simulating each of the real experimential conditions.Comment: 6 pages, REVTEX, 4 ps figure

    Power-law cosmological solution derived from DGP brane with a brane tachyon field

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    By studying a tachyon field on the DGP brane model, in order to embed the 4D standard Friedmann equation with a brane tachyon field in 5D bulk, the metric of the 5D spacetime is presented. Then, adopting the inverse square potential of tachyon field, we obtain an expanding universe with power-law on the brane and an exact 5D solution.Comment: 8 pages, 1 figure, accepted by IJMP

    Correspondence Between DGP Brane Cosmology and 5D Ricci-flat Cosmology

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    We discuss the correspondence between the DGP brane cosmology and 5D Ricci-flat cosmology by letting their metrics equal each other. By this correspondence, a specific geometrical property of the arbitrary integral constant I in DGP metric is given and it is related to the curvature of 5D bulk. At the same time, the relation of arbitrary functions μ\mu and ν\nu in a class of Ricci-flat solutions is obtained from DGP brane metric.Comment: 8 pages, 1 figure, accepted by MPLA, added referenc

    Dark Energy in Global Brane Universe

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    We discuss the exact solutions of brane universes and the results indicate the Friedmann equations on the branes are modified with a new density term. Then, we assume the new term as the density of dark energy. Using Wetterich's parametrization equation of state (EOS) of dark energy, we obtain the new term varies with the red-shift z. Finally, the evolutions of the mass density parameter Ω2\Omega_2, dark energy density parameter Ωx\Omega_x and deceleration parameter q_2 are studied.Comment: 8 pages,4 figure

    5D5D Solutions to Λ\LambdaCDM Universe Derived from Global Brane Model

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    An exact solution of brane universe is studied and the result indicates that Friedmann equations on the brane are modified with an extra term. This term can play the role of dark energy and make the universe accelerate. In order to derive the Λ\LambdaCDM Universe from this global brane model, the new solutions are obtained to describe the 5D5D manifold.Comment: 7 pages, no figure, accepted by MPL

    Progress towards quantum simulating the classical O(2) model

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    We connect explicitly the classical O(2)O(2) model in 1+1 dimensions, a model sharing important features with U(1)U(1) lattice gauge theory, to physical models potentially implementable on optical lattices and evolving at physical time. Using the tensor renormalization group formulation, we take the time continuum limit and check that finite dimensional projections used in recent proposals for quantum simulators provide controllable approximations of the original model. We propose two-species Bose-Hubbard models corresponding to these finite dimensional projections at strong coupling and discuss their possible implementations on optical lattices using a 87^{87}Rb and 41^{41}K Bose-Bose mixture.Comment: 7 pages, 6 figures, uses revtex, new material and one author added, as to appear in Phys. Rev.

    Single top or bottom production associated with a scalar in \gamma p collision as a probe of topcolor-assisted technicolor

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    In the framework of the topcolor-assisted technicolor (TC2) models, we study the productions of a single top or bottom quark associated with a scalar in \gamma-p collision, which proceed via the subprocesses c\gamma -> t\pi_t^0, c\gamma -> t h_t^0 and c\gamma -> b\pi^+_t mediated by the anomalous top or bottom coupling tc\pi_t^0, tch_t^0 and bc\pi_t^+. These productions, while extremely suppressed in the Standard Model, are found to be significantly enhanced in the large part of the TC2 parameter space, especially the production via c\gamma -> b\pi^+ can have a cross section of 100 fb, which may be accessible and allow for a test of the TC2 models.Comment: 13 pages, 4 figures, comments and references adde
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