Math 507   Fall 2020   Schedule

Lec. Date Topic Section
  1   8/24     Introduction, examples and questions.                      
  2   8/26     Contractions.     1.1  
  3   8/28     Weak contractions. Increasing interval maps.   -, 1.1  
  4   8/31     Attracting fixed points.  Circle rotations.     -, 1.3  
  5   9/2     Circle rotations. Topological transitivity and minimality.     1.3  
  6   9/4     Circle rotations: equidistribution. First digits of powers.    
  7   9/7     Translations and linear flows on the torus.     1.4, 1.5  
  8   9/9     Criteria for topological transitivity.     1.4  
  9   9/11     Transitivity of translations and linear flows on the torus.   1.4, 1.5  
  10   9/14     Times-m map of the circle.     1.7  
  11   9/16     Times-m map of the circle. Shifts on sequences and semiconjugacy.     1.7  
  12   9/18     Topological conjugacy and semiconjugacy.    
  13   9/21     Full shift on m symbols.     1.9  
  14   9/23     Topological mixing.  Subshifts of finite type.     1.9  
  15   9/25     Subshifts of finite type: periodic points, transitivity and mixing.   1.9  
  16   9/28     Exponential growth rate of the number of periodic points.     1.9, 3.1  
  17   9/30     Definitions of topological entropy.     3.1  
  18   10/2     Topological entropy: Examples of calculation.   3.2  
  19   10/5     Properties of topological entropy     3.1  
  20   10/7     Linear maps of the plane.     1.2  
  21   10/9     Hyperbolic automorphisms of T2 :  basics and an example.   1.8  
  22   10/12     Hyperbolic automorphisms of T2 :  mixing and periodic points.     1.8  
  23   10/14     Calculation of topological entropy.  Hyperbolic automorphisms of TN.      
  24   10/16     Structural stability: definition and examples, Em.   2.3, 2.4(c)
  25   10/19     Structural stability: Em and hyperbolic automorphisms of T2.     2.4(c), 2.6  
  26   10/21     Coding: general, expanding circle maps.     2.5(a), 2.4(b)  
  27   10/23     Conjugacy to Em via coding.  Smale's horseshoe.   2.4(b), 2.5(c)  
  28   10/26     Coding of a hyperbolic automorphism of T2.     2.5(d)  
  29   10/28     Hyperbolic dynamical systems.      
  30   10/30     Workshop in Dynamical Systems and Related topics    
  31   11/2     Recurrence properties:  ω- and α-limit sets, recurrent points.     3.3  
  32   11/4     Recurrence properties:  nonwandering points.     3.3  
  33   11/6     More on recurrence properties. Poincare Recurrence Theorem.     4.1(f)
  34   11/9     Rotation number.     11.1  
  35   11/11     Rotation number: invariance under top. conjugacy,  the rational case.     11.1  
  36   11/13     Irrational rotation number: conjugacy and semiconjugacy.     11.2, 12.1,2
  37   11/16     Continuous-time dynamical systems (Flows)      
  38   11/18     Flows: topological mixing, recurrence, topological entropy.      
  39   11/20     Is f the time-one map of a flow?   Suspension flow.  
        Thanksgiving Break      
  40   11/30     Properties of suspension flows.  Equivalence for flows.     2.2  
  41   12/2     Geodesics and geodesic flow.     5.4  
  42   12/4     Project presentations.    
  43   12/7     Project presentations.      
  44   12/9     Project presentations.      
  45   12/11     Project presentations.