1/10 Fourier coefficients of periodic functions
uniform convergence and L^2 convergence
statement of convergence theorems
complex form of Fourier series
Problems from 3-1
due 1/22: 4,9,10,11
1/15 Fourier series as best L^2 approximation
Bessel's ineq., Parseval's equality
Weierstrass's theorem (statement)
Proof of L^2 convergence for cts. functions
Problems from 3-2
due 1/24: 2(a),5,12
1/17 No class (talk in Washington,DC)
Make-up TBA
1/22 Uniformly convergent series/improper integrals
Weierstrass M-test
Uniform convergence of Fourier series
Piecewise C^k functions-decay of Fourier coeffs.
Problems: 3-3 no. 4, 3-4 no. 2 (due 1/31)
1/24 Riemann-Lebesgue lemma, decay of coefficients
Cesaro convergence: Fejer's theorem[not in text!]
Proof of Weierstrass' theorem
Problems from 3-2: 10, 16(d) (prove the statement made,
assuming 16(c)) (due 1/31) solutions
1/29 Pointwise convergence; Dirichlet's kernel
Fourier transforms of L^1 functions
Problems: 3-4: 5,6; 3-3 1,2 (due 2/12)
1/31 discussion of homework problems
Fourier transform: derivatives, Gaussians
Convolution theorem [not in text!]
2/5 Eigenfunctions of b.v.p. on an interval
Formal solution of 1DWE with Dirichlet BCs
Conditions on the data for convergence
Problems: 4-2 1,3,9,10 (due 2/14) solutions
5-1 1(a)(b)(c); 3,4 (all due 2/19)
2/7 discussion of HW: Lipschitz and Holder
conditions, solving ODEs w/ Fourier transforms
1DWE with Dirichlet BCs: existence theorem
2/12 WE on an interval: uniqueness, stability
Heat eqn on an interval, Dirichlet BCs: existence
2/14 Maximum principle for the heat equation
Applications: uniqueness, stability
Heat equation with source term (formal solution)
5-2:2,7 4-3:5,6 5-3:5 solutions
2/19 Heat equation with source term-conditions for
convergence
Duhamel's principle for second order ODEs [not in text!]
Wave equation with forcing term (Dirichlet): formal sln.
2/21 WE with forcing term: convergence
D'Alembert's representation formula for the WE;
solution of the WE for C^2 data
Solution of the heat eqn for continuous data
2/26 Heat kernel in an interval (Dirichlet)
Representation of the solution
HW problems: non-hom heat equation
2/28 Discussion of homework problems
3/5 EXAM 1 (open book)problems
solutions
3/7 Heat kernel on
the real line:
derivation using Laplace transform, properties,
examples of solutions of the IVP
3/12 Solution of the IVP for the heat
equation: proof
of convergence, examples. Uniqueness and
maximum principle.
3/14 Comparison of the heat and wave equation.
Non-homogeneous problems via Duhamel's principle
HE and WE on the half-line (Dirichlet)
3/17- 3/22 SPRING BREAK
3/26 Laplacian in R^2,R^3 (polar coords.);
Green's identities
Uniqueness for BVPs in bounded regions
Harmonic polynomials in R^2,R^3
3/28 Green's functions for R^2,R^3
Representation formula in R^3; solution of Poisson's eqn.
Poisson's kernel for a disk in R^2
4/2 Poisson kernel in R^3
Applications: solution of Dirichlet's problem for a ball (theorem);
mean-value property, maximum principle
homework
problems (due 4/11)-PDF
4/4 Harnack's inequality and
Liouville's theorem
Stokes representation formula on bounded domains
Green's functions and Poisson kernel for domains
Poisson formula for the upper-half space
4/9 Heat kernel in
R^n; solution of Cauchy problem
Uniqueness, non-hom h.e. in R^n
max/min principle (bounded domains)
homework
problems (due 4/16)-PDF
4/11 Examples: heat eqn on a 3D
strip and in upper-half plane
Eigenvalues of symmetric operators: spectral theorem, positivity
of eigenvalues of the Laplacian
4/16 Eigenfunction expansions
Eigenvalues of a square, solution of IVPs
Eigenvalues of a disk, Bessel functions
4/16, afternoon: problem session (homework problems)
4/18 EXAM 3 problems
solutions
4/23 Example: Neumann eigenvalues
of a cylinder, heat eqn.
Spectrum of a ball in R^3
4/23, afternoon: problem session (exams 2 and 3)
4/25 Cauchy problem for
the WE in R^3: Kirchoff's formula
Huygens' principle
Solution of Cauchy's problem in R^2, failure of Huygens' prple
4/29, 5:00- problem session
review problems (PDF
file)
solutions (problem
4)
5/4 Final Exam
problems
(page 1)
problems(page
2)
solutions(page
1)
solutions(page
2)