Introduction to Topology

  • Instructor: Gábor Moussong
  • Contact: gabor.moussong@ttk.elte.hu
  • Prerequisites: Firm knowledge of standard concepts of first-year calculus (like limits and continuity, manipulating with sets and fuctions) is indispensable. Basic understanding of standard notions of group theory (not much more than uderstanding the meaning of the terms group, subgroup, homomorphism, isomorphism) will also be necessary in the last third of the course.
  • Text: "First steps in topology" notes by G. Moussong

Course description: Beginner's introduction to fundamental concepts of topology. The first part of the course deals with abstract point-set topology, and the second part introduces some more geometric and algebraic ideas.

Topics:

  • Introduction: Some motivating questions coming from geometry and calculus. The concept of continuity in metric spaces.
  • Basic definitions: Topological spaces, open and closed sets. Continuous maps, homeomorphisms, topological invariants. Limits, Hausdorff spaces.
  • Constructions: Subspaces, products, quotients.
  • Connectedness and compactness of topological spaces.
  • Cut-and-paste topology: Gluings, constructions of surfaces. Sketch proof of the classification theorem of closed surfaces.
  • Homotopy: Homotopic maps, homotopy type of spaces, homotopy invariants.
  • The fundamental group: Definitions and methods of calculation, some applications.