MATH 516 Fall 2011 Lecture Summary


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Date Contents References
1 0905
Labour Day
0907 outline, examples of DE, basic questions, concepts of solutions
0909 Part I. Classical linear equations
§2.1 transport equation with constant velocity
§2.2 Laplace equation: fundamental solution and solution formula
[Evans]
2.1, 2.2
[John]
4.4, 4.5
[GT] 2.8
2 0912 proof of solution formula using Green's identity
mean value theorem
0914 properties of harmonic functions: maximal principle, uniqueness and smoothness
0916 more properties: derivative estimates, Liouville theorem, Harnack inequality
3 0919 Green's fucntion
0921 Green's fucntions for half space and balls
0923
h1 due
sketch of existence theory: Dirichlet Principle and Perron's method of subsolutions
4 0926 §2.3 heat equation: fundamental solution and solution formula, Duhamel's principle
[Evans]
2.3
[John]
Ch.7
0928 maximal principle and uniqueness in bounded domains and in whole space
0930
proof of MP in whole space, Tikhonov's example, scaling
5 1003
regularity and derivative estimates
1005
§2.4 wave equation: solution formula in 1D
spherical means and Euler-Poisson-Darboux equation
[Evans]
2.4
1007
h2 due
solution formulas in higher dimensions
domains of dependence and influence
6 1010
Thanksgiving

1012
Part II. Sobolev spaces
Banach space, Holder spaces, Lebesgue spaces, weak derivative
[Evans]
Ch.5
1014
examples of weak derivative, Sobolev spaces
7 1017
examples and basic properties, 3 stages of approximations
1019
Proof of approximation theorems
1021
Sobolev imbedding, Sobolev and Morrey's inequalities
8 1024
Proof of Morrey's inequality, Sobolev imbedding in bounded domains
1026
h3 due
extension theorem
1028
compactness
9 1031
Poincare inequality; Imbedding of W^{1,n} into BMO; H^{-1}; trace
1102
Part III. Weak solutions of elliptic equations in divergence form
overview, weak formulation, Lax-Milgram theorem
[Evans]
6.1-6.4
1104
h4 due
an example of nonexistence/nonuniqueness, first existence theorem
10 1107
Fredholm Alternative, second existence theorem
1109
spectrum of a compact linear operator and third existence theorem (eigenvalues); statement of interior H^2 regularity
1111
Remembrance Day
11 1114
Lemma on difference quotient and Sobolev space, proof of interior H^2 estimate
1116
Higher regularity and boundary regularity, statement of maximal principle
1118
proof of weak maximal principle, Hopf's Lemma
12 1121
h5 due
strong maximal principle
Part IV. Linear evolution equations
weak solution and semigroup approaches, weak formulation of parabolic equations, vector valued Sobolev spaces (§5.9.2)
[Evans]
7.1, 7.4
1123
Galerkin method, energy estimate
1125
energy estimate continued, existence and uniqueness of weak solutions by Galerkin method
13
1128
uniqueness continued; semigroup: examples and definition, generator
1130
basic properties of generators, Hille-Yosida theorem
1202
examples of semigroups from evolution PDE

h6 due Christmas