时间：2018年11月8日（周四），上午：10:00-11:00
题目：Integrability of quad equations: CAC vs. BT
报告地点：闻理园A4--305室
报告摘要：We consider two-dimensional lattice equations defined on an elementary square of the Cartesian lattice and depending on the variables at the corners of the quadrilateral. For such equations the definition often used for integrability is that of ``multidimensional consistency'' (MDC): it should be possible to extend the equation consistently from two to three dimensions. In practice this is done by checking ``Consistency- Around-a-Cube'' (CAC). It is often assumed that the equations on the six sides of the cube are the same (up to lattice parameters), but this assumption was relaxed in the classification of Boll. We discuss the results of a search and classification of homogeneous quadratic triplets of multidimensionally consistent lattice equations, allowing different equations on the three orthogonal planes (hence triplets) but using the same equation on parallel planes. No assumptions are made about symmetry or tetrahedron property. The results are then grouped by subset/limit properties, and analyzed by the effectiveness of their Bäcklund transformations, or equivalently, by the quality of their Lax pair (fake or not).
报告人简介：Jarmo Hietarinta 教授分别于1972年和1975年获美国纽约州立大学石溪分校物理学硕士和博士学位，1977-79年，在美国Ohio州立大学，Maryland大学从事博士后研究，1980起于芬兰Turku大学物理系任职，2004年起任Turku大学数学与自然科学学院院长。是世界著名数学物理学家，在国际同行中威望很高。长期从事孤子理论和可积系统研究，同时对微分几何、代数拓扑等数学工具在理论物理、量子物理中的应用有很深造诣。是Symmetries & Integrability of Difference Equations 系列会议历任委员，多次担任主席和副主席。在《Physics Reports》、《Physical Review A》, 《Physical Review D》、《Physical Review Letters》等高水平国际期刊上发表SCI学术论文150余篇，其中数十篇论文的均为高他引论文，单篇最高他引次数达400余次。
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理学院/大数据学院
非线性分析研究所
2018年11月6日
