Topological Spaces

gentle introduction to the subject, leading the reader to understand the notion of what is important in topology with regard to geometry. Divided into three sections - The line and the plane, Metric spaces and Topological spaces -, the book eases the move into higher levels of abstraction. Students are thereby informally assisted in learning new ideas while remaining on familiar territory. The authors do not assume previous knowledge of axiomatic approach or set theory. Similarly, they have restricted the mathematical vocabulary in the book so as to avoid overwhelming the reader, and the concept of convergence is employed to allow students to focus on a central theme while moving to a natural understanding of the notion of topology. The pace of the book is relaxed with gradual acceleration: the first nine sections form a balanced course in metric spaces for undergraduates while also containing ample material for a two-semester graduate course. Finally, the book illustrates the many connections between topology and other subjects, such as analysis and set theory, via the inclusion of "Extras" at the end of each chapter presenting a brief foray outside topology.

Contenu

I The Line And The Plane.- 1 What Topology Is About.- Topological Equivalence.- Continuity and Convergence.- A Few Conventions.- Extra: Topological Diversions.- Exercises.- 2 Axioms for ?.- Extra: Axiom Systems.- Exercises.- 3 Convergent Sequences and Continuity.- Subsequences.- Uniform Continuity.- The Plane.- Extra: Bolzano (1781-1848).- Exercises.- 4 Curves in the Plane.- Curves.- Homeomorphic Sets.- Brouwer's Theorem.- Extra: L.E.J. Brouwer (1881-1966).- II Metric Spaces.- 5 Metrics.- Extra: Camille Jordan (1838-1922).- Exercises.- 6 Open and Closed Sets.- Subsets of a Metric Space.- Collections of Sets.- Similar Metrics.- Interior and Closure.- The Empty Set.- Extra: Cantor (1845-1918).- Exercises.- 7 Completeness.- Extra: Meager Sets and the Mazur Game.- Exercises.- 8 Uniform Convergence.- Extra: Spaces of Continuous Functions.- Exercises.- 9 Sequential Compactness.- Extra: The p-adic Numbers.- Exercises.- 10 Convergent Nets.- Inadequacy of Sequences.- Convergent Nets.- Extra: Knots.- Exercises.- 11 Transition to Topology.- Generalized Convergence.- Topologies.- Extra: The Emergence of the Professional Mathematician.- Exercises.- III Topological Spaces.- 12 Topological Spaces.- Extra: Map Coloring.- Exercises.- 13 Compactness and the Hausdorff Property.- Compact Spaces.- Hausdorff Spaces.- Extra: Hausdorff and the Measure Problem.- Exercises.- 14 Products and Quotients.- Product Spaces.- Quotient Spaces.- Extra: Surfaces.- Exercises.- 15 The Hahn-Tietze-Tong-Urysohn Theorems.- Urysohn's Lemma.- Interpolation and Extension.- Extra: Nonstandard Mathematics.- Exercises.- 16 Connectedness.- Connected Spaces.- The Jordan Theorem.- Extra: Continuous Deformation of Curves.- Exercises.- 17 Tychonoff's Theorem.- Extra: The Axiom of Choice.- Exercises.- IV Postscript.- 18 A Smorgasbord for Further Study.- Countability Conditions.- Separation Conditions.- Compactness Conditions.- Compactifications.- Connectivity Conditions.- Extra: Dates from the History of General Topology.- Exercises.- 19 Countable Sets.- Extra: The Continuum Hypothesis.- A Farewell to the Reader.- Literature.- Index of Symbols.- Index of Terms.