Symmetric central configurations
in the concave 4-Body problem
with two pairs of equal masses
报告专家：刘杨杉山 博士后 （南开大学）
报告时间：5月15日（周五）16:00-17:00
报告地点：四川大学数学学院东302
报告摘要：
We establish the existence of a single-parameter family of the concave kite central configurations in the 4-body problem with two pairs of equal masses. In such configurations, one pair of masses must lie on the base of an isosceles triangle, and the other pair on its symmetric axis with one mass positioned inside the triangle formed by the other three. Using a rigorous computer-assisted analytical approach, we prove that for any non-negative mass ratio, the number of such configurations is either zero, one, or two, thereby providing a complete classification of this family. Furthermore, we show that the unique configuration corresponding to a specific mass ratio is a fold-type bifurcation point within the reduced subspace. We also give a clear and complete bifurcation picture for both symmetric and asymmetric cases of this concave type across the entire planar 4-body configuration space.
专家简介：
刘杨杉山，博士毕业于四川大学数学学院，导师为张世清教授，现为南开大学陈省身数学所博士后，研究方向主要为天体力学中的N体问题的中心构型，特别是涉及平面4体、5体问题中心构型的有限性、唯一性以及分叉等方面的研究。目前已在SIAM J. Appl. Dyn. Syst.，J. Geom. Phys.以及Discrete Contin. Dyn. Syst.发表文章3篇。
邀请人：张世清
