Here I shall try to keep an updated account of what has been
done so far in the course.
date |
what we did |
comments |
28/3 |
- introduction to the course
- first order scalar equations, some special cases
(example of non-uniqueness and explosinon of solutions)
- equations with separable variables
|
page 1-7 of my notes (see main page)
|
29/3 |
- more on separable equations: uniqueness
- homogeneous equations
- linear equations (scalar, first order)
|
page 8-13 of my notes
|
31/3 |
- The Bernoulli and Riccati equations
- The general initial value problem
- Lipschitz conditions, uniqueness
|
|
4/4 |
- The existence theorem
- Extension of solutions
|
for 31/3 and 4/4: page 14-24 in the notes
|
5/4 |
- The lab: how to use ode45
- How to make systems out of higher order equations
- Numeical methods, Euler (with convegence theorem, not
yet the proof), Heun, Runge Kutta
|
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7/4 |
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25/4 |
- A very short recollection of what we did before Easter break
- Maximal solutions: the theorem and the proof
- Differential inequalities and the Gronwall lemma
|
|
26/4 |
- Exercises
- Introduction to linear systems: the existence proof.
|
The proof of Lipschitz continuity was not very clear ... an
explanation can be found in
this note
|
28/4 |
- Linear algebra
- Linear systems: three equivalent statements about
solutions to systems of ode's
|
|
2/5 |
- Results around the (very important) statement that the
set of solutions to a system of ode's form an n-dimensional
subspace of C1.
- The fundamental solution, and the variation of
constants formula
|
|
3/5 |
- Stability and continuous dependence on data and small
perturbations of a linear system
- Systems with constant coefficients. The matrix
exponential and some properties of functions of matrices
|
Corresponds to pages up to 56 in the notes
|
9/5 |
- The Cayley-Hamilton theorem and the evaluation of
analytical functions of a matrix
- Fundamental solutions for linear equations of higher order.
|
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10/5 |
- Notions of stability of solutions to differential equations
- A stability theorem for solutions to equations of the
form
y' = A y + g(t,y)
|
|
12/5 |
-
- Proof of an instability theorem for equations of the
type
y' = A y + g(t,y)
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16/5 |
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17/5 |
- Lyapunov-functions, an example
- Two point boundary value problems
- Fundamental solutions
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19/5 |
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