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| Content Provider | Springer Nature Link |
|---|---|
| Author | Chen, Guantao Chen, Beifang |
| Copyright Year | 2008 |
| Abstract | Let G be an infinite graph embedded in a closed 2-manifold, such that each open face of the embedding is homeomorphic to an open disk and is bounded by finite number of edges. For each vertex x of G, define the combinatorial curvature $$\Phi_G(x) = 1 - \frac{d(x)}{2} + \sum_{\sigma \in F(x)} \frac{1}{|\sigma|}$$ as that of [8], where d(x) is the degree of x, F(x) is the multiset of all open faces σ in the embedding such that the closure $$\bar\sigma$$ contains x (the multiplicity of σ is the number of times that x is visited along ∂σ), and |σ| is the number of sides of edges bounding the face σ. In this paper, we first show that if the absolute total curvature ∑ x∈V(G) |Φ G (x)| is finite, then G has only finite number of vertices of non-vanishing curvature. Next we present a Gauss-Bonnet formula for embedded infinite graphs with finite number of accumulation points. At last, for a finite simple graph G with 3 ≤ d G (x) < ∞ and Φ G (x) > 0 for every x ∈ V(G), we have (i) if G is embedded in a projective plane and #(V(G)) = n ≥ 1722, then G is isomorphic to the projective wheel P n ; (ii) if G is embedded in a sphere and #(V(G)) = n ≥ 3444, then G is isomorphic to the sphere annulus either A n or B n ; and (iii) if d G (x) = 5 for all x ∈ V(G), then there are only 49 possible embedded plane graphs and 16 possible embedded projective plane graphs. |
| Ending Page | 183 |
| Page Count | 25 |
| Starting Page | 159 |
| File Format | |
| ISSN | 09110119 |
| e-ISSN | 14355914 |
| Journal | Graphs and Combinatorics |
| Issue Number | 3 |
| Volume Number | 24 |
| Language | English |
| Publisher | Springer Japan |
| Publisher Date | 2008-06-12 |
| Publisher Place | Japan |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Enumeration in graph theory Topology of $E^2$ , $2$ -manifolds Gauss-Bonnet formula Embedding Finiteness theorem Engineering Design Asymptotic enumeration Relations with graph theory Face cycle Planar graphs; geometric and topological aspects of graph theory Combinatorial curvature Euler relation Infinite graph Combinatorics |
| Content Type | Text |
| Resource Type | Article |
| Subject | Discrete Mathematics and Combinatorics Theoretical Computer Science |
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