Class Diary for M447, Fall 2009, Jochen Denzler


Wed Aug 19: Quick review of logic through p 19. Hwk: Ex 2.4 (not collected)
Fri Aug 21: Functions; injective; surjective etc. Field axioms Hwk. from 2.20 the part relating to (2.5); 2.21.2; 2.27
Mon Aug 24: Ordered fields; the supremum axiom; The example R(X) as an ordered field that doesn't satisfy the sup axiom (and not the archimedean property either)
Wed Aug 26: Properties and proofs for supremum. Hwk: 2.32, 2.34.2 due Fri
Fri Aug 28: Supremum finished up; Archimedean property as a consequence of sup axiom. A 10 min overview how one could (alternatively) construct the reals from scratch.
Mon Aug 31: Hwk comments. Cardinality. A few paradoxes mentioned.
Wed Sep 02: Sequences. Metric spaces barely defined.
Fri Sep 04: Examples for metric spaces, and basic consequences of the definition. Hwk: draw balls for 1,2,and infinity distances respectively in R^2, possibly also for a few other p if you wish -- see addenda
Mon Sep 07: LABOR DAY
Wed Sep 09: another example of a metric space: rationals with p-adic distance. -- Open and closed sets. Hwk: Show that A-interior is always open, A-closure is always closed, and that the complement of the closure of a set is the interior of thhe complement. Not for turn-in -- Here is your Hwk for grading due Mon
Fri Sep 11: Sequences in metric spaces; limit and cluster points.
Mon Sep 14: Continuity. Hwk due Friday for grading. Also read sec 3.4 carefully by Wed
Wed Sep 16: Comments on returned hwk; including well-ordering principle (see sample sols made availbale). Continuity finished up. limsup and semi-continuity.
Fri Sep 18: comments on pending hwk; New hwk on semicontinuity Exercise 3.4.X1, (1)-(4) due Wed for grading. Sequential compactness. [For later convenience, please amend all references to compactness in Sec 3.5 before Rmk 3.5.13. Write `sequentially compact' instead of compact.]
Mon Sep 21: Heine-Borel. Continuity and compactness. Cover compactness defined and motivated.
Wed Sep 23: Discussion of returned homework. Handed out notes on additional material. Hwk deadline for 3.4.X1 extended
Fri Sep 25: Basic theorems about cover compactness
Mon Sep 28: compactness continued
Wed Sep 30: equivalence of cover and sequential compactness
Fri Oct 02: compactness finished up.
Mon Oct 05: Cantor set and fat Cantor sets; subspace matric: open and closed as relative notions.
Wed Oct 07: subspace metric: continuity, compactness, isometries, homeomorphisms
Fri Oct 09: product metrics; topological equivalence.
Mon Oct 12: EXAM 1
Wed Oct 14: Lipschitz functions. Product of compact metric spaces is compact. Rn begun; vector space operations; norm, inner product, Cauchy-Schwarz.
Fri Oct 16: FALL BREAK
Mon Oct 19: Product spaces finished, and Heine-Borel for R^n
Wed Oct 21: Connectedness.
Fri Oct 23: Connectedness finished; metric completeness. Hwk: read and hand in problem solutions on the first page of
this by Wed
Mon Oct 26: Comments about Fri hwk; Complex numbers
Wed Oct 28: comments on belated semicontinuity, and on new hwk. complex sequences.
Fri Oct 30: More on sequences; Inequality of arithmetic and geometric mean proved and used for an alternative proof for Ex 4.12
Mon Nov 02: Series. Hwk till next Mon: from addenda, Hwk3.11.X1 and X2; read but don't do X3. Also do Ex 4.22 from notes; but I won't collect it for grading.
Wed Nov 04: proof of multiplicatioon of series theorem.
Fri Nov 06: alternating series; an example of two conditionally convergent series whose (formal) product is divergent; rearrangement of absolutely convergent series; all the weird stuff caused by rearrangement of conditionally convergent series
Mon Nov 09: Cauchy test for series with decreasing, positive terms. Feedback for hwk 3.9X1-3: uniform convergence vs pointwise convergence.
--- Tue Nov 10: WP/WF drop deadine ---
Wed Nov 11: formal power series; convergent power series; radius of convergence
Fri Nov 13: reciprocal of a power series with non-zero constant term; formal and convergence proof by majorant method. (See notes handed out)
Mon Nov 16: pointwise and monotone convergence; uniform convgence
Wed Nov 18: uniform convergence, exchange of limits, and consequences
Fri Nov 20: Uniform convergence of power series on compact disks inside the disk of convergence. Differentiation of power series.
Mon Nov 23:
Wed Nov 25: EXAM 2
Fri Nov 27: THANKSGIVING BREAK
Mon Nov 30:
Wed Dec 02: STUDY DAY
Mon Dec 07: FINAL EXAM 08:00-10:00 (scheduled by university policy)

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