Math 234: Advanced Dynamical Systems
Spring 2008

Contents of this page

Late breaking news
Lecture time and location
Prerequisite
Office hours
Textbook
Syllabus
Exams
Grading policy
Handouts
Homework
Policy on calculators
Academic integrity
Anonymous feedback

Late breaking news

(5/20) Final exam solutions are here. Homework 8 solutions have also been posted. I'm about to submit the grades; you can email me to find out what you got.

It was a fun class for me to teach, hope it was at least half as fun for you to take it. Have a great summer and hope to see you next semester!

(5/13) I just posted solutions to Homework 7.

(5/12) The paper is actually due on May 19, the same day as the exam, not May 21 as I mistakenly wrote below. Sorry for the confusion.

(5/11) The final exam is here! It's due on Monday, May 19, by 2 PM. Please let me know if you have any questions.

(5/7) The final version of the survey paper is due on May 21, the same day (and time) the final exam is due. You can also just email me a PDF file with the paper. If you haven't already done so, please typeset the paper in LaTeX. If you need help with it, please let me know. Here's a general guide to LaTeX and a short math guide.

Also, please let me know as soon as you can if you'd like to present in the morning (between 10:15 and 11:15) or in the afternoon (between 3 and 4) on Monday, May 12, and if you need an LCD projector. We'll be meeting in MH 331B both at 10:15 and at 3.

(5/6) Recall that tomorrow we are meeting in MH 320 (at 3 as usual). I'll be giving a colloquium talk entitled "What is a... hyperbolic system?" A good companion reading on this topic is this paper by Araujo and Viana.

(4/29) Homework 8 (the last one) has been posted and is due on May 12.

(4/26) Remember that there will be a problem session on Monday, April 28. Let's meet in MH 331B at 10:15, as usual.

(4/24) I posted homework 6 solutions.

(4/22) Homework 7 corrections: in Exercise 7.2.3, it should say "any number less than half the diameter of the space is a sensitivity constant". Thanks to Michael Pejic for pointing this out. (Btw, a hint for this problem: optimize the proof of Proposition 7.2.14.) At the back of the book there is an incorrect hint for Exercise 7.2.1: the hint should be 1/2, not 1/4. A more specific hint: work with E_2 in additive notation and represent each number between 0 and 1 in base 2; then E_2 shifts the binary digits to the left by one slot. Given an epsilon > 0, choose a natural number N so that 2^{-N} < epsilon. When is d(x,y) < 2^{-N}?

And also: HW 7 deadline has now shifted to Monday, April 28.

(4/20) Tomorrow I'll be about 1/2 hour late to my morning office hours, i.e., I'll arrive around 10:30. I'll make that time up in the afternoon between 2 and 3 (I'll be in and out, so please let me know if you plan to stop by). Also, you can turn in homework 7 on Wednesday.

Finally, I just posted a handout entitled "Problem 6.1.10" (and an application of the Baire category theorem).

(4/13) Homework 7 has been posted and is due on Monday, April 21.

Remember that we do have a problem session tomorrow, April 14 at 10:15 (in MH 331B). I will talk about the bouncing ball system from the handout.

Regarding the survey paper, please give me a first draft by May 5 so I can give you some feedback before you present it. The presentations will be on May 12, in the morning from 10:15 to 11:10 (instead of the usual problem session) and afternoon 3-4.

(4/6) Rememeber that we will have a problem session tomorrow, April 7, from 10:15 to around 11:15. Let's meet in MH 331B. Also, I just (finally!) posted solutions to homework 5.

(4/1) It's no joke: homework 6 has been posted and is due on Wednesday, April 9. Hope everyone had an excellent spring break!

(3/21) Homework 4 solutions have been posted.

(3/20) Midterm solutions are here.

Two other potential topics for the survey paper are billiards and the Lorentz attractor.

Enjoy your spring break and see you on April 2!

(3/12) Here are some potential topics for the survey paper:
Geodesic flows of surfaces of constant negative curvature;
Morse-Smale systems;
Anosov systems;
Birkhoff's ergodic theorem;
Structural stability (esp. of flows on closed surfaces);
The N-body problem.

Feel free to suggest other topics.

Also, here's the midterm. Don't hesitate to email me with questions.

(3/4, part 2) I just posted Homework 5. It's due on Wednesday, March 12.

(3/4) I just posted homework 3 solutions. I'll post HW 5 later today. Also, the dates for the remaining problem sessions are 3/10, 3/31, 4/14, 4/28, and 5/12 (with possible small variations).

(2/26) HW 2 solutions have just been posted.

(2/25, part 2) I just uploaded a more correct version of that hint I posted two days ago. Thanks to Michael Pejic for pointing out the incorrect part.

(2/25) Homework 4 has been posted and is due on March 3.

(2/24) Here's another hint for Exercise 3.3.3, concerning so called subadditive sequences. The result in the lemma is important in its own right.

(2/23) I was just reminded that, due to family obligations, I will not be able to hold the problem session this Monday, Feb. 25, at 10:15. I suggest that we meet the following Monday (March 3) at 10:15 instead. (This way we'll have a problem session two weeks in a row, which will be useful for preparing for the midterm.) I really apologize for this.

(2/21) Homework 1 solutions have been posted. Remember that the first problem session will be on Monday, Febrary 25, at 10:15, in MH 331B.

(2/15) Homework 3 has been posted and is due on Monday, February 25.

Here are some hints. Exercise 3.3.2: use Prop. 3.3.3 and a property of norms in a Euclidean space. Exercise 3.3.3: first show the limit on the RHS exists and is independent of norm, then show that LHS is less than or equal to the RHS (use the property that if k is an eigenvalue of A than k^n is an eigenvalue of A^n), then finally show that the RHS is less than or equal to the LHS using again Prop. 3.3.3. Exercise 3.3.4: use a well-known formula for the trace of A in terms of the eigenvalues of A. Hope this helps!

(2/8) Starting on Monday, February 11, we will be meeting in SH 239 on Mondays and Wednesdays at 3 o'clock.

(2/5) My office hours tomorrow will be from 10 to 11:30 and from 3 to 4. Sorry for frequent changes. They are due to hiring committee duties I have this semester and my other class (CAMCOS) still not reaching a stable equilibrium.

More importantly, since it seems that it would work with all the registered students, I will try to move the class to start at 2:50. Please let me know ASAP if you have any objections. I'll let you know if and when I get us a new classroom.

A hint for part of the problem 2.2.13, to show that for every x the sequence of iterates (x_n) of f converges to the unique fixed point x_0, consider the set A of all accumulation (i.e., limit) points of A. This is the set of limits of all convergent subsequences of (x_n). Show that f(A) is necessarily contained in A. Show that the sequence |x_n - x_0| converges, say to some number d and that A is contained in the set with two elements x_0 - d, x_0 + d. Then use the weak contractive property of f.

A hint for exercise 2.4.6: suppose p is a periodic point of period 3, so that p, f(p), f(f(p)) are all distinct. Consider all possible cases: p < f(p) < f(f(p)), f < f(f(p)) < f(p), etc. and in each one derive a contradiciton.

(2/3) Homework 2 has just been posted and is due on February 11.

(1/27) Since we have a candidate for a faculty position visiting the department tomorrow, I will only have office hours from 2:30 to 4. If you have time, you should come to his talk at 1:30. Also, I just posted Homework 1, which is due on Monday, February 4. The assignment is from the Hasselblatt-Katok (HK) book; note that they call some problems "exercises" and others "problems for further study".

(1/17) Welcome to the home page for Math 234 for Spring 2008! If you are planning to take this class, please register as soon as possible. If you need a permission number, please email me to get one. We need at least six people in order for the class to run. This is the very first time Math 234 is offered, so it would be a pity for it to get cancelled.

If you are still not sure if you want to take the class, feel free to email me for more information.


Lecture time and location

MW 3:00-4:00 in SH 239 + an hour long discussion section every two weeks (meeting times will be decided in class)

Prerequisite

Math 134 (with a grade of "C-" or better) or instructor consent.

The course will be fairly self-contained (i.e., we won't be assuming too much from Math 134).


Office hours

MW 10-11:30 and 1-2, and by appointment


Textbook

Boris Hasselblatt and Anatole Katok, A First Course in Dynamics: with a Panorama of Recent Developments, Cambridge University Press, 2003

We will also use other books, but they are not required for the class:

M. W. Hirsch, S. Smale, and R. L. Devaney: Differential Equations, Dynamical Systems, and an Introduction to Chaos, Elsevier/Academic Press, second edition, 2003. ERRATA

John Guckenheimer and Philip Holmes, Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields, Applied Mathematical Sciences, vol. 42, Springer, 1983 (or 2002)

Steven Strogatz, Nonlinear Dynamics and Chaos: With Applications to Physics, Biology, Chemistry and Engineering, Perseus, 2001


Syllabus

The backbone of the course will be the Course part of the main textbook (Chapters 2-8) and a few chapters from the Panorama part (especially Chapters 10, 12, and 13, and perhaps others, time permitting). These topics will be interwoven with various examples from the other sources listed above.

Greensheet


Exams

There will be one take-home midterm and a take-home final exam. In addition, each student will write a short research paper and present it in class. More details will be provided later.

The exam schedule:

The midterm exam will be assigned on March 12, 2008.
The final exam will be assigned on May 12, 2008
There will be no make-up exams.


Grading policy

Homework 20%, Midterm 20%, Paper and presentation 20%, Final 40%


Handouts

V. Araujo and M. Viana, Hyperbolic dynamical systems

Problem 6.1.10 from H-K and an application of the Baire category theorem


Homework

Late homework policy. One class meeting late: 50% penalty; two class meetings late: no credit.

# Due date Assignment Solutions
1 2/4 Exercise 2.2.6, problems 2.2.13, 2.2.14 (HK, p. 45) (pdf). HW 1
2 2/11 Exercise 2.3.4, 2.4.6, 2.5.3, 2.5.4 (pdf). HW 2
3 2/25 Exercise 3.3.2, 3.3.3, 3.3.4. HW 3
4 3/3 Exercise 4.1.3, 4.1.8, 4.1.9. HW 4
5 3/12 Homework 5 (pdf) HW 5
6 4/9 Exercise 6.1.1, 6.1.2, 6.1.4-6.1.7 HW 6
7 4/23 Exercise 7.1.2, 7.2.1, 7.2.3 HW 7
8 5/12 Exercise 7.2.5, 7.3.1, 7.2.11 HW 8



Academic integrity

By default, I regard my students as honest individuals and expect them to abide by the University policy on academic integrity.


Anonymous feedback

If you have any comments or suggestions, please fill out this anonymous feedback form.
Slobodan N. Simić

Last modified: Tue May 20 14:06:36 PDT 2008