1,720,994 research outputs found

    Search for integrable two-component versions of the lattice equations in the ABS-list

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    We search and classify two-component versions of the quad equations in the ABS list, under certain assumptions. The independent variables will be called y,zy,z and in addition to multilinearity and irreducibility the equation pair is required to have the following specific properties: (1) The two equations forming the pair are related by yzy\leftrightarrow z exchange. (2) When z=yz=y both equations reduce to one of the equations in the ABS list. (3) Evolution in any corner direction is by a multilinear equation pair. One straightforward way to construct such two-component pairs is by taking some particular equation in the ABS list (in terms of yy), using replacement yzy \leftrightarrow z for some particular shifts, after which the other equation of the pair is obtained by property (1). This way we can get 8 pairs for each starting equation. One of our main results is that due to condition (3) this is in fact complete for H1, H3, Q1, Q3. (For H2 we have a further case, Q2, Q4 we did not check.) As for the CAC integrability test, for each choice of the bottom equations we could in principle have 828^2 possible side-equations. However, we find that only equations constructed with an even number of yzy \leftrightarrow z replacements are possible, and for each such equation there are two sets of "side" equation pairs that produce (the same) genuine B\"acklund transformation and Lax pair.Comment: 14 pages, final versio

    Degree growth of lattice equations defined on a 3x3 stencil

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    We study complexity in terms of degree growth of one-component lattice equations defined on a 3×33\times 3 stencil. The equations include two in Hirota bilinear form and the Boussinesq equations of regular, modified and Schwarzian type. Initial values are given on a staircase or on a corner configuration and depend linearly or rationally on a special variable, for example fn,m=αn,mz+βn,mf_{n,m}=α_{n,m}z+β_{n,m}, in which case we count the degree in zz of the iterates. Known integrable cases have linear growth if only one initial values contains zz, and quadratic growth if all initial values contain zz. Even a small deformation of an integrable equation changes the degree growth from polynomial to exponential, because the deformation will change factorization properties and thereby prevent cancellations.19 pages, to appear in Open Communications in Nonlinear Mathematical Physics , Special Issue in Memory of Decio Lev

    On the parametrization of solutions of the Yang--Baxter equations

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    We study all five-, six-, and one eight-vertex type two-state solutions of the Yang-Baxter equations in the form A12B13C23=C23B13A12A_{12} B_{13} C_{23} = C_{23} B_{13} A_{12}, and analyze the interplay of the `gauge' and `inversion' symmetries of these solution. Starting with algebraic solutions, whose parameters have no specific interpretation, and then using these symmetries we can construct a parametrization where we can identify global, color and spectral parameters. We show in particular how the distribution of these parameters may be changed by a change of gauge.Comment: 19 pages in LaTe

    Darboux and Binary Darboux Transformations for Discrete Integrable Systems. II. Discrete Potential mKdV Equation

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    The paper presents two results. First it is shown how the discrete potential modified KdV equation and its Lax pairs in matrix form arise from the Hirota-Miwa equation by a 2-periodic reduction. Then Darboux transformations and binary Darboux transformations are derived for the discrete potential modified KdV equation and it is shown how these may be used to construct exact solutions.One of the author (YS) would like to acknowledge Professor Jarmo Hietarinta for his useful suggestions and hospitality when the author visited Turku University. The authors (YS and JXZ) also thank for the financial support from NSFC (Grant Numbers 11501510, 11271362, 11271266)

    Scattering of Solitons and Dromions

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    New Integrable Systemsa

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    Searching for integrable (P)DEs

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