论文标题

革命的革命和不对称的两次革命的von Mangoldt表面,简单切割基因座结构

Generalized von Mangoldt surfaces of revolution and asymmetric two-spheres of revolution with simple cut locus structure

论文作者

Tanaka, Minoru, Akamatsu, Toyohiro, Sinclair, Robert, Yamaguchi, Masaru

论文摘要

众所周知,如果在革命$(r^2,dr^2+m(r)^2dθ^2)$沿每个子午线上的高斯曲率函数正在减少,那么每个点的切割基因座的缩短基因座是空的,则是空的或相反的Meridian $ thece $ theme $ theme sede sepertion Assepers。革命。革命的表面$(r^2,dr^2+m(r)^2dθ^2)$称为革命的广义von mangoldt革命表面,如果每个点的切割基因座的$θ^{ - 1}(-1}(0)$是空的,或者是相反的子午线$θ^{ - 1}(-1}( - 1}(π)。 dr^2+m_0(r)^2dθ^2),$其中$ m_0(x):= x/(1+x^2),$具有与上述相同的切割基因座结构,并且每个点的切割基因座和$ r^{ - 1}(((0,\ infty))中的每个点的切割基因座是非空的。请注意,对于该表面,高斯曲率函数并没有沿着子午线降低。在本文中,我们为革命的表面提供了足够的条件$(r^2,dr^2+m(r)^2dθ^2)$成为革命的广义von Mangoldt表面。此外,我们证明,对于有限的总曲率$ c的任何革命表面,存在着广义的von mangoldt革命表面,具有相同的总曲率$ c $,因此,沿着子午线的高斯曲率功能并不是$ [a,\ infty)$。

It was known that if the Gaussian curvature function along each meridian on a surface of revolution $(R^2, dr^2+m(r)^2dθ^2)$ is decreasing, then the cut locus of each point of $θ^{-1}(0)$ is empty or a subarc of the opposite meridian $θ^{-1}(π).$ Such a surface is called a von Mangoldt's surface of revolution. A surface of revolution $(R^2, dr^2+m(r)^2dθ^2)$ is called a generalized von Mangoldt surface of revolution if the cut locus of each point of $θ^{-1}(0)$ is empty or a subarc of the opposite meridian $θ^{-1}(π).$ For example, the surface of revolution $(R^2, dr^2+m_0(r)^2dθ^2),$ where $m_0(x):=x/(1+x^2),$ has the same cut locus structure as above and the cut locus of each point in $r^{-1}( (0, \infty ) )$ is nonempty. Note that the Gaussian curvature function is not decreasing along a meridian for this surface. In this article, we give sufficient conditions for a surface of revolution $(R^2, dr^2+m(r)^2dθ^2)$ to be a generalized von Mangoldt surface of revolution. Moreover, we prove that for any surface of revolution with finite total curvature $c,$ there exists a generalized von Mangoldt surface of revolution with the same total curvature $c$ such that the Gaussian curvature function along a meridian is not monotone on $[a,\infty)$ for any $a>0.$

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