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1.
这篇文章得到了以根节点的次、割边的个数及环的个数为参数的双树梵和的色和方程,且导出了这类地图带以上三个参数的精确解及一些退化的情形。  相似文献   

2.
本文讨论了带根双奇异平面地图的计数问题,提供了以根面次、度和内面数为参数及以根面次、奇异边数和自环数为参数的计数函数所满足的计数方程,并且导出了所有的计数显式.  相似文献   

3.
有根无环平面地图节点剖分计数方程   总被引:2,自引:0,他引:2  
一个平面地图,如果无有边是环,则称为是无环的.有根的意义与[1]中的相同.在那里对于此类地图的一些计数问题作了研究,但从未触及到节点剖分.这篇文章的主要目的在于研究这类地图的依节点剖分的计数.求出了有根无环平面地图依节点剖分计数的母函数所满足的一个泛函方程.并且,作为这一方程的一种应用,求出了一类在节点的最大次给定情况下的有根无环平面地图依节点剖分计数的一些结果.  相似文献   

4.
本文提供了环面上带边数和根面次这两个参数的有根近三角剖分的函数方程及其参数表达式,并给出了根面次为1以边数为参数的有根近三角剖分地图的精确解.  相似文献   

5.
本文研究至多有两个无公共边圈的有根平面地图,提出了这种地图的节点剖分计数函数和以它的根次、边数和一次点数为三个参数的计数函数所满足方程。  相似文献   

6.
李赵祥  刘彦佩 《数学学报》2004,47(3):487-494
本文研究了平面上一般带根地图的色和与双色和,得到了这类地图的色和与双色和函数方程。从这类地图的色和函数方程,导出了平面上一般无环地图、平面上二部地图和平面上欧拉地图的计数函数方程。还得到了一些计数函数的计数显式。  相似文献   

7.
近三正则3—连通平面地图的计数   总被引:2,自引:0,他引:2  
蔡俊亮  刘彦佩 《数学进展》2001,30(2):149-155
本文提供了便于依根点次,边数和根面次计数近三正则3-连通有根平面地图的一个函数方程,继之得到其参数形式解,并由此通过Lagrange反演导出了它的计数显示,本文推广了[3]和[4]的结果。  相似文献   

8.
本文研究了球面和射影平面上对偶无环不可分近三角剖分带根地图的以根面次和内面数为参数的计数问题,得到了这类地图在球面和射影平面上的计数函数满足的方程.还得到了射影平面上2连通地图一个参数的显示表达式和渐近估计式.  相似文献   

9.
有根不可分离平面偶地图的计数   总被引:3,自引:0,他引:3  
本文给出了由边数和根面的次作为指标的有根不可分离平面偶地图的计数函数所满足的函效方程,此方程是三次的。而,有根一般平面偶地图的相应计数函数所满足的方程却是二次的。从此后一个方程出发得到了上面提到的二个计数函数的具体形式。同时,发现了这个有根不可分离平面偶地图的计数函数与Fabonacci叙列的关系。  相似文献   

10.
本文给出了可定向曲面(亏格2,3)和不可定向曲面(亏格5)上根瓣丛以边数为参数时相应的计数显式.与此同时,考虑一类与瓣从拓扑等价的地图类: (无环,简单)近2-正则地图,通过一种组合方法,给出了多参数下平面近2一正则地图的计数显式,亦得到了任意亏格曲面上该类地图的具体个数.  相似文献   

11.
Enumeration of maps on the projective plane   总被引:1,自引:0,他引:1  
1. IntroductionA lnap is rooted if an edge is distinguished togetl1er with an end and a side of the edge.An edge belo11ging to only one face is called double (or 8ingular by some author), al1 othersbelonging to exactly two faces are called s1ngle. The enumeration of rooted p1anar maps wasfirst introduced by Tutte['], Techniques originated by Tutte [2,3l for enumerating variousclasses of rooted Inaps on tIle sphere are here applied to the c1asses of alI rooted maps onthe projective plane. Th…  相似文献   

12.
数有根近2-正则平面地图   总被引:2,自引:0,他引:2  
郝荣霞  蔡俊亮 《东北数学》2004,20(3):265-270
The number of rooted nearly 2-regular maps with the valency of root-vertex, the number of non-rooted vertices and the valency of root-face as three parameters is obtained. Furthermore, the explicit expressions of the special cases including loopless nearly 2-regular maps and simple nearly 2-regular maps in terms of the above three parameters are derived.  相似文献   

13.
This paper investigates the number of rooted unicursal planar maps and presents some formulae for such maps with four parameters: the numbers of nonrooted vertices and inner faces and the valencies of two odd vertices.  相似文献   

14.
A map is 4-regular unicursal if all its vertices are 4-valent except two odd-valent vertices. This paper investigates the number of rooted 4-regular unicursal planar maps and presents some formulae for such maps with four parameters: the number of edges, the number of inner faces and the valencies of the two odd vertices.  相似文献   

15.
A new functional relation, whose unique solution is the generating function of rooted planar maps, is shown. This new relation in conjunction with the well-known relation established by Tutte, enables the easy derivation of a system of parametric equations for the wanted generating function. As a consequence, we infer a closed formula counting the rooted planar maps as a function of their number of vertices and faces. The geometrical nature of the decomposition used in the derivation of this functional relation, leads to the definition of a natural notion of the inner map of a rooted planar map. Some questions related to this notion are treated.  相似文献   

16.
Two combinatorial identities obtained by the author are used to simplify formulas for the number of general rooted cubic planar maps, for the number of g-essential maps on surfaces of small genus, and also for rooted Eulerian maps on the projective plane. Besides, an asymptotics for the number of maps with a large number of vertices is obtained.  相似文献   

17.
Enumerating near-4-regular maps on the sphere and the torus   总被引:2,自引:0,他引:2  
In this paper rooted near-4-regular maps on the plane and the torus are counted with formulae with respect to four parameters: the root valency, the number of edges, the inner faces, and nonroot-vertex loops. In particular, the number of rooted near-4-regular maps on those surfaces with exactly k nonroot-vertex loops is investigated.  相似文献   

18.
We present a bijection for toroidal maps that are essentially 3-connected (3-connected in the periodic planar representation). Our construction actually proceeds on certain closely related bipartite toroidal maps with all faces of degree 4 except for a hexagonal root-face. We show that these maps are in bijection with certain well-characterized bipartite unicellular maps. Our bijection, closely related to the recent one by Bonichon and Lévêque for essentially 4-connected toroidal triangulations, can be seen as the toroidal counterpart of the one developed in the planar case by Fusy, Poulalhon and Schaeffer, and it extends the one recently proposed by Fusy and Lévêque for essentially simple toroidal triangulations. Moreover, we show that rooted essentially 3-connected toroidal maps can be decomposed into two pieces, a toroidal part that is treated by our bijection, and a planar part that is treated by the above-mentioned planar case bijection. This yields a combinatorial derivation for the bivariate generating function of rooted essentially 3-connected toroidal maps, counted by vertices and faces.  相似文献   

19.
This article presents new bijections on planar maps. At first a bijection is established between bipolar orientations on planar maps and specific “transversal structures” on triangulations of the 4-gon with no separating 3-cycle, which are called irreducible triangulations. This bijection specializes to a bijection between rooted non-separable maps and rooted irreducible triangulations. This yields in turn a bijection between rooted loopless maps and rooted triangulations, based on the observation that loopless maps and triangulations are decomposed in a similar way into components that are respectively non-separable maps and irreducible triangulations. This gives another bijective proof (after Wormald’s construction published in 1980) of the fact that rooted loopless maps with n edges are equinumerous to rooted triangulations with n inner vertices.  相似文献   

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