Introduction / 1.: |
Representation of graphs / 1.1.: |
Drawings / 1.1.1.: |
Incidence matrix / 1.1.2.: |
Euler's theorem on valence sum / 1.1.3.: |
Adjacency matrix / 1.1.4.: |
Directions / 1.1.5.: |
Graphs, maps, isomorphisms / 1.1.6.: |
Automorphisms / 1.1.7.: |
Exercises / 1.1.8.: |
Some important classes of graphs / 1.2.: |
Walks, paths, and cycles; connectedness / 1.2.1.: |
Trees / 1.2.2.: |
Complete graphs / 1.2.3.: |
Cayley graphs / 1.2.4.: |
Bipartite graphs / 1.2.5.: |
Bouquets of circles / 1.2.6.: |
New graphs from old / 1.2.7.: |
Subgraphs / 1.3.1.: |
Topological representations, subdivisions, graph homeomorphisms / 1.3.2.: |
Cartesian products / 1.3.3.: |
Edge-complements / 1.3.4.: |
Suspensions / 1.3.5.: |
Amalgamations / 1.3.6.: |
Regular quotients / 1.3.7.: |
Regular coverings / 1.3.8.: |
Surfaces and imbeddings / 1.3.9.: |
Orientable surfaces / 1.4.1.: |
Nonorientable surfaces / 1.4.2.: |
Imbeddings / 1.4.3.: |
Euler's equation for the sphere / 1.4.4.: |
Kuratowski's graphs / 1.4.5.: |
Genus of surfaces and graphs / 1.4.6.: |
The torus / 1.4.7.: |
Duality / 1.4.8.: |
More graph-theoretic background / 1.4.9.: |
Traversability / 1.5.1.: |
Factors / 1.5.2.: |
Distance, neighborhoods / 1.5.3.: |
Graphs colorings and map colorings / 1.5.4.: |
Edge operations / 1.5.5.: |
Algorithms / 1.5.6.: |
Connectivity / 1.5.7.: |
Planarity / 1.5.8.: |
A nearly complete sketch of the proof / 1.6.1.: |
Connectivity and region boundaries / 1.6.2.: |
Edge contraction and connectivity / 1.6.3.: |
Planarity theorems for 3-connected graphs / 1.6.4.: |
Graphs that are not 3-connected / 1.6.5.: |
Kuratowski graphs for higher genus / 1.6.6.: |
Other planarity criteria / 1.6.8.: |
Voltage Graphs and Covering Spaces / 1.6.9.: |
Ordinary voltages / 2.1.: |
Drawings of voltage graphs / 2.1.1.: |
Fibers and the natural projection / 2.1.2.: |
The net voltage on a walk / 2.1.3.: |
Unique walk lifting / 2.1.4.: |
Preimages of cycles / 2.1.5.: |
Which graphs are derivable with ordinary voltages? / 2.1.6.: |
The natural action of the voltage group / 2.2.1.: |
Fixed-point free automorphisms / 2.2.2.: |
Cayley graphs revisited / 2.2.3.: |
Automorphism groups of graphs / 2.2.4.: |
Irregular covering graphs / 2.2.5.: |
Schreier graphs / 2.3.1.: |
Relative voltages / 2.3.2.: |
Combinatorial coverings / 2.3.3.: |
Most regular graphs are Schreier graphs / 2.3.4.: |
Permutation voltage graphs / 2.3.5.: |
Constructing covering spaces with permutations / 2.4.1.: |
Preimages of walks and cycles / 2.4.2.: |
Which graphs are derivable by permutation voltages? / 2.4.3.: |
Identifying relative voltages with permutation voltages / 2.4.4.: |
Subgroups of the voltage group / 2.4.5.: |
The fundamental semigroup of closed walks / 2.5.1.: |
Counting components of ordinary derived graphs / 2.5.2.: |
The fundamental group of a graph / 2.5.3.: |
Contracting derived graphs onto Cayley graphs / 2.5.4.: |
Surfaces and Graph Imbeddings / 2.5.5.: |
Surfaces and simplicial complexes / 3.1.: |
Geometric simplicial complexes / 3.1.1.: |
Abstract simplicial complexes / 3.1.2.: |
Triangulations / 3.1.3.: |
Cellular imbeddings / 3.1.4.: |
Representing surfaces by polygons / 3.1.5.: |
Pseudosurfaces and block designs / 3.1.6.: |
Orientations / 3.1.7.: |
Stars, links, and local properties / 3.1.8.: |
Band decompositions and graph imbeddings / 3.1.9.: |
Band decomposition for surfaces / 3.2.1.: |
Orientability / 3.2.2.: |
Rotation systems / 3.2.3.: |
Pure rotation systems and orientable surfaces / 3.2.4.: |
Drawings of rotation systems / 3.2.5.: |
Tracing faces / 3.2.6.: |
Which 2-complexes are planar? / 3.2.7.: |
The classification of surfaces / 3.2.9.: |
Euler characteristic relative to an imbedded graph / 3.3.1.: |
Invariance of Euler characteristic / 3.3.2.: |
Edge-deletion surgery and edge sliding / 3.3.3.: |
Completeness of the set of orientable models / 3.3.4.: |
Completeness of the set of nonorientable models / 3.3.5.: |
The imbedding distribution of a graph / 3.3.6.: |
The absence of gaps in the genus range / 3.4.1.: |
The absence of gaps in the crosscap range / 3.4.2.: |
A genus-related upper bound on the crosscap number / 3.4.3.: |
The genus and crosscap number of the complete graph K[subscript 7] / 3.4.4.: |
Some graphs of crosscap number 1 but arbitarily large genus / 3.4.5.: |
Maximum genus / 3.4.6.: |
Distribution of genus and face sizes / 3.4.7.: |
Algorithms and formulas for minimum imbeddings / 3.4.8.: |
Rotation-system algorithms / 3.5.1.: |
Genus of an amalgamation / 3.5.2.: |
Crosscap number of an amalgamation / 3.5.3.: |
The White-Pisanski imbedding of a cartesian product / 3.5.4.: |
Genus and crosscap number of cartesian products / 3.5.5.: |
Imbedded Voltage Graphs and Current Graphs / 3.5.6.: |
The derived imbedding / 4.1.: |
Lifting rotation systems / 4.1.1.: |
Lifting faces / 4.1.2.: |
The Kirchhoff Voltage Law / 4.1.3.: |
Imbedded permutation voltage graphs / 4.1.4.: |
An orientability test for derived surfaces / 4.1.5.: |
Branched coverings of surfaces / 4.1.7.: |
Riemann surfaces / 4.2.1.: |
Extension of the natural covering projection / 4.2.2.: |
Which branch coverings come from voltage graphs? / 4.2.3.: |
The Riemann-Hurwitz equation / 4.2.4.: |
Alexander's theorem / 4.2.5.: |
Regular branched coverings and group actions / 4.2.6.: |
Groups acting on surfaces / 4.3.1.: |
Graph automorphisms and rotation systems / 4.3.2.: |
Regular branched coverings and ordinary imbedded voltage graphs / 4.3.3.: |
Which regular branched coverings come from voltage graphs? / 4.3.4.: |
Applications to group actions on the surface S[subscript 2] / 4.3.5.: |
Current graphs / 4.3.6.: |
Ringel's generating rows for Heffter's schemes / 4.4.1.: |
Gustin's combinatorial current graphs / 4.4.2.: |
Orientable topological current graphs / 4.4.3.: |
Faces of the derived graph / 4.4.4.: |
Nonorientable current graphs / 4.4.5.: |
Voltage-current duality / 4.4.6.: |
Dual directions / 4.5.1.: |
The voltage graph dual to a current graph / 4.5.2.: |
The dual derived graph / 4.5.3.: |
The genus of the complete bipartite graph K[subscript m, n] / 4.5.4.: |
Map Colorings / 4.5.5.: |
The Heawood upper bound / 5.1.: |
Average valence / 5.1.1.: |
Chromatically critical graphs / 5.1.2.: |
The five-color theorem / 5.1.3.: |
The complete-graph imbedding problem / 5.1.4.: |
Triangulations of surfaces by complete graphs / 5.1.5.: |
Quotients of complete-graph imbeddings and some variations / 5.1.6.: |
A base imbedding for orientable case 7 / 5.2.1.: |
Using a coil to assign voltages / 5.2.2.: |
A current-graph perspective on case 7 / 5.2.3.: |
Orientable case 4: doubling 1-factors / 5.2.4.: |
About orientable cases 3 and 0 / 5.2.5.: |
The regular nonorientable cases / 5.2.6.: |
Some additional tactics / 5.3.1.: |
Nonorientable cases 3 and 7 / 5.3.2.: |
Nonorientable case 0 / 5.3.4.: |
Nonorientable case 4 / 5.3.5.: |
About nonorientable cases 1, 6, 9, and 10 / 5.3.6.: |
Additional adjacencies for irregular cases / 5.3.7.: |
Orientable case 5 / 5.4.1.: |
Orientable case 10 / 5.4.2.: |
About the other orientable cases / 5.4.3.: |
Nonorientable case 5 / 5.4.4.: |
About nonorientable cases 11, 8, and 2 / 5.4.5.: |
The Genus of a Group / 5.4.6.: |
The genus of abelian groups / 6.1.: |
Recovering a Cayley graph from any of its quotients / 6.1.1.: |
A lower bound for the genus of most abelian groups / 6.1.2.: |
Constructing quadrilateral imbeddings for most abelian groups / 6.1.3.: |
The symmetric genus / 6.1.4.: |
Rotation systems and symmetry / 6.2.1.: |
Reflections / 6.2.2.: |
Quotient group actions on quotient surfaces / 6.2.3.: |
Alternative Cayley graphs revisited / 6.2.4.: |
Group actions and imbeddings / 6.2.5.: |
Are genus and symmetric genus the same? / 6.2.6.: |
Euclidean space groups and the torus / 6.2.7.: |
Triangle groups / 6.2.8.: |
Groups of small symmetric genus / 6.2.9.: |
The Riemann-Hurwitz equation revisited / 6.3.1.: |
Strong symmetric genus 0 / 6.3.2.: |
Symmetric genus 1 / 6.3.3.: |
The geometry and algebra of groups of symmetric genus 1 / 6.3.4.: |
Hurwitz's theorem / 6.3.5.: |
Groups of small genus / 6.3.6.: |
An example / 6.4.1.: |
A face-size inequality / 6.4.2.: |
Statement of main theorem / 6.4.3.: |
Proof of Theorem 6.4.2: valence d = 4 / 6.4.4.: |
Proof of Theorem 6.4.2: valence d = 3 / 6.4.5.: |
Remarks about Theorem 6.4.2 / 6.4.6.: |
References / 6.4.7.: |
Bibliography |
Supplementary Bibliography |
Table of Notations |
Subject Index |