搜索结果: 16-30 共查到“知识库 图论”相关记录301条 . 查询时间(1.171 秒)
A graph is K2,3-saturated if it has no subgraph isomorphic to K2,3, but does contain a K2,3 after the addition of any new edge. We prove that the minimum number of edges in a K2,3-saturated graph on n...
Convex Graph Invariants
Graphs graph invariants convex optimization spectral invariants majorization
2011/1/17
The structural properties of graphs are usually characterized in terms of invariants, which
are functions of graphs that do not depend on the labeling of the nodes. In this paper we study
convex gra...
A sufficient condition for the existence of an anti-directed 2-factor in a directed graph
sufficient condition existence anti-directed 2-factor
2011/1/18
Let D be a directed graph with vertex set V and order n. An anti-directed (hamiltonian) cycle H in D is a (hamiltonian) cycle in the graph underlying D such that no pair of consecutive arcs in H form ...
We provide a short proof that a 5-connected nonplanar apex graph contains a subdivided K5 or a K−4 (= K4 with a single edge removed) as a subgraph. Together with a recent result of Ma and Yu tha...
The Kelmans-Seymour conjecture states that the 5-connected nonplanar graphs contain a subdivided K5 .
W-graph ideals
W-graph ideals
2011/1/18
We introduce a concept of a W- graph ideal in a Coxeter group.The main goal of this paper is to describe how to construct a W- graph from a given W- graph ideal. The principal application of this idea...
Skyrmions, Rational Maps & Scaling Identities
Skyrmions Rational Maps & Scaling Identities
2010/12/28
Starting from approximate Skyrmion solutions obtained using the rational map ansatz, improved approximate Skyrmions are constructed using scaling arguments.Although the energy improvement is small, th...
Systematic method of generating new integrable systems via inverse Miura maps
modified integrable systems Lax representation
2011/3/2
We provide a new natural interpretation of the Lax representation for an integrable system; that is, the spectral problem is the linearized form of a Miura transformation between the original system a...
On a lexical tree for the middle-levels graph problem
lexical tree middle-levels graph problem
2011/1/18
A conjecture of I. H´avel asserts that all middle-levels graphs Mk of the (2k + 1)-cubes possess Hamilton cycles. In this work, a tree containing all vertices of certain reduced graphs of the Mk...
Parallelogram decompositions and generic surfaces in H^{hyp}(4)
Parallelogram decompositions generic surfaces
2011/1/18
The space Hhyp(4) consists of pairs (M, ω), whereM is a hyper-elliptic Riemann surface of genus 3, and ω is a holomorphic 1-form having only one zero, which is located at a Weierstrass point of M.
The generalized connectivity of complete bipartite graphs
k-connectivity complete bipartite graph edge-disjoint spanning trees
2011/2/28
Let G be a nontrivial connected graph of order n, and k an integer with 2 ≤k ≤ n. For a set S of k vertices of G, let κ(S) denote the maximum number ℓ of edge-disjoint trees T1, T2, . . . , T...
Cohen-Macaulayness of bipartite graphs, revisited
edge ideal of a graph Cohen-Macaulay bipartite graph
2011/1/17
Cohen-Macaulayness of bipartite graphs is investigated by several mathematicians and has been characterized combinatorially. In this note, we give some different combi-natorial conditions for a bipart...
Bifurcation diagrams on iso-energetic levels of the Kowalevski-Yehia gyrostat
Bifurcation diagrams iso-energetic levels Kowalevski-Yehia gyrostat
2011/3/3
Предложен новый взгляд на классификацию бифуркационных диаграмм и условия существования критических движений интегрируемой задачи о движении тяжелого гиростата при условиях типа Кова-левской (случай и...
Distance-balanced closure of some graphs
Distances in graphs distance-balanced graphs distance-balanced closure
2011/2/22
In this paper we prove that any distance-balanced graph G with (G) |V (G)| − 3 is regular. Also we define notion of distance-balanced closure of a graph and we find distance-
balanced closur...
Hierarchical Gompertzian growth maps with application in astrophysics
Hierarchical Gompertzian growth maps application in astrophysics
2010/12/28
The Gompertz model describes the growth in time of the size of significant quantities associated to a large number of systems, taking into account nonlinearity features by a linear equation satisfied ...