If you have any preferences for what special topics (the ones that could change from year to year in my version of this course) you would like to see covered at the end, please let me know. Nonlinear science is a very big field, and if anybody is particularly interested in covering something, I will endeavor to say something about relevant material.

Just let me know.

## Sunday, 31 January 2010

### Typos Corrected in Homework 2

I have uploaded a revised version of homework sheet 2 in which minor typos have been corrected. There are two such typos:

(1) In problem 1, I changed the phrasing from "find" the phase portrait to "plot" the phase portrait to make it clearer.

(2) In problem 2c, I made the definition of q-twisted state more explicit, even though it was actually there anyway.

Neither of these typos should have caused any problems.

(1) In problem 1, I changed the phrasing from "find" the phase portrait to "plot" the phase portrait to make it clearer.

(2) In problem 2c, I made the definition of q-twisted state more explicit, even though it was actually there anyway.

Neither of these typos should have caused any problems.

**Update (2/01/10):**There is an additional typo that might be a bit problematic. In problem 3, omega_1 = omega_3 starting in part (b). I inadvertently forgot to type that and hope that this has not caused any problems. I also found a minor typo in (3), which I have corrected (there is a factor of K missing in the denominator in the definition of rho).## Thursday, 28 January 2010

### Remaining Class Times (And then there were 5...)

Classes (5) and (7), as numbered in the blog entry below, have now been culled.

Class (1) is about to be culled, though it's still currently listed.

Class (1) is about to be culled, though it's still currently listed.

### There exist only 5 classes

As you have seen from the MI websites, classes 5 and 7 have been culled. Class 1 is in the process of being culled, although it's still listed (with 3 students in it) as of this morning.

Thank you for your patience with this process.

Thank you for your patience with this process.

### Reversible Systems

I was e-mailed about reversible systems because of question (1) in homework sheet 1, and here is my answer (that I am posting here because it is relevant for everybody):

I checked the definition of reversible system after the lecture to check

whether I had a typo (given the question that came up). I don't remember

what I wrote on the board, but the one in the scanned lecture notes is

correct. Because of that, I didn't bring it up again in lecture the next

time.

In fact, it should be g(x,-y) = g(x,y), so it sounds like I put an extra

minus sign in the lectures.

You want invariance under (t,y) -> (-t,-y).

I checked the definition of reversible system after the lecture to check

whether I had a typo (given the question that came up). I don't remember

what I wrote on the board, but the one in the scanned lecture notes is

correct. Because of that, I didn't bring it up again in lecture the next

time.

In fact, it should be g(x,-y) = g(x,y), so it sounds like I put an extra

minus sign in the lectures.

You want invariance under (t,y) -> (-t,-y).

## Wednesday, 27 January 2010

### Lecture Notes posted up through page 43

Read the title.

Also, homework sheet 2 has been posted for a week or so, and homework sheet 3 will be posted shortly.

Also, homework sheet 2 has been posted for a week or so, and homework sheet 3 will be posted shortly.

## Sunday, 24 January 2010

### Problem Sheet 1 corrected

I forgot to put an equal sign in the statement of problem 7(a). This has now been corrected.

Subscribe to:
Posts (Atom)