Forelesningslogg

Here you will find what we have covered in the lectures Notes_10Jan25, with the reference to the pages in the Lectures Notes and the books.

Date Content Reference
22 august - Complex numbers
- Conjugate and Modulus. Representation of circles and lines
- Polar coordinate representation. The argument
notes pp. 5–10
also, Sarason Sections I.1–I.5 and I.9
23 august - The Exponential Form, and De Moivre's Formula
- Roots of Complex Numbers
- The Extended Complex plane \(\mathbb C_\infty \)
- The Stereographic Projection
notes pp. 10–15
also, Sarason Sections I.9–I.12
29 august - The Spherical metric
- Topology and convergence in \(\mathbb C \)
- Continuity of complex functions
- We covered pp. 21–29 from the notes, mostly without proofs.
I suggest to skim through this part.
notes p. 16 and pp. 21–29
also, Sarason Sections I.8, I.13, I.14.
30 august - Continuity of Principal Argument and Root
- Take a quick look at uniform continuity
- Connectedness and Path-Connectedness (proofs in the notes)
- Complex Differentiability
- Operations with differentiable functions (proofs in the notes)
- The Cauchy–Riemann Equations
notes pp. 30–37 (right before Corollary 2.34)
also, Sarason Sections II.1–II.6
5 september - Consequences of the Cauchy-Riemann Equations
- Inverse function Theorem for Holomorphic maps
- Differentiation of curves in \(\mathbb C \)
- Conformal mappings
notes pp. 38–41
also, Sarason Sections II.7, II.8, II.11, II.12
6 september - End of the proof of Theorem 2.42
- Harmonic maps
- Harmonic conjugates
- The Complex Exponential
- Theorem 2.48 (proved until part (vi))
notes pp. 41–44
also, Sarason Sections IV.1–IV.5 and II.12–II.16
12 september - End of the proof of Theorem 2.48
- Complex trigonometric/hyperbolic functions
- Branches of the argument
- Holomorphic Roots
notes pp. 44–48
also, Sarason Sections IV.6–IV.13
13 september - Holomorphic Logarithms
- Complex Powers
- Series of complex numbers
- Convergence and Absolute convergence
- The Cauchy Product of two series
notes pp. 48–50, 55–58
also, Sarason Sections V.1–V.7
19 september - Pointwise, absolute, and uniform convergence
- Weierstrass M-test
- Power Series. The Radius of Convergence. Abel's Lemma
- The Cauchy-Hadamard Theorem/Formula
- Worked Examples
notes pp. 58–64
also, Sarason Chapter V
20 september - Worked Examples
- Convergence in the Boundary.
- Abel's Summation by Parts. Picard's Criterion
- Holomorphicity of power series (entirely rigorous proof in Theorem 3.20
of the notes, not in the lectures)
- \(\mathbb C^\infty \) regularity and Taylor expansions
notes pp. 64–69
also, Sarason Chapter V
26 september - Analytic Functions. Analyticity of Power Series
- Worked Examples
- Operations with Power Series and Analytic Functions
- Identity Principles for Analytic Functions
notes pp. 69–76
27 september - Path Integral and Arc-Length Integral
- Elementary properties of the integrals
- The Fundamental Theorem of Calculus
- Examples of Path-Integrals
notes 79–86
also, Sarason Chapter VI
03 oktober - Differentiation under integral sign
- Computing a fundamental integral
- The Cauchy-Goursat Theorem
- Cauchy Theorem/Primitives in Convex Domains
- Thw Winding Numbers
notes pp. 86–93
also, Sarason Chapter VII
04 oktober - Cauchy Integral Formula in Convex Domains
- Local Cauchy Theorem
- Holomorphic Extension to a point
- Mean Value Property
- Cauchy Formulae and Estimates for the Derivatives
- Morera Theorem
- Weierstrass Convergence Theorem
notes pp. 93–97
also, Sarason Chapter VII
10 oktober - Analiticity of holomorphic functions
- Order of a zero of a function
- Identity Principles
- Liouville's Theorem
- The Fundamental Theorem of Algebra
notes pp. 98–101
also, Sarason Chapter VII
11 oktober - The Fundamental Theorem of Algebra (Proof)
- The Maximum Modulus Principles
- Schwarz's Lemma
notes pp. 101–104
also, Sarason Chapter VII
17 oktober - Proof of Schwarz's Lemma
- Laurent Series
- Cauchy Theorem in Annuli
- Laurent Series Expansion of Functions
- Isolated Singularities
notes pp. 104, pp. 111–117
also, Sarason Chapter VIII
18 oktober - Types of Singularities
- Removable Singularities: Riemann Theorem
- Characterizations for Poles
- Essential Singularities: The Casorati-Weierstrass Theorem
- Definition of Residue
notes pp. 117–121
also, Sarason Chapter VIII
24 oktober - Useful results to compute residues:
See Propositions 5.19, 5.20, 5.22, 5.23, 5.25 and Examples 5.21, 5.24.
- Cauchy Global/Homological Theorem
- The Cauchy Residues Theorem
- Evaluation of a complex integral via Residues Theorem
notes pp. 121–130
also, Sarason Chapter VIII
25 oktober - Trigonometric Integrals (of bounded functions) in \(\mathbb [0,2\pi] \)
- Integrals in \( \mathbb R \) of Functions without real singularities
- Mixed Trigonometric-Rational Integrals in \( \mathbb R \)
- Integrals in \( \mathbb R \) of Functions with simple real poles
notes pp. 131–137
also, Sarason Chapter X
31 oktober - Example Integral with simple real poles
- Trigonometric Polynomials
- Fourier Coefficients, Sums, Series
- Examples
- Bessel's Inequality
notes pp. 137-138, pp. 143–146
also, Krantz Chapter XIII
01 november - Convergence of Fourier Series of Lipschitz functions
- Fourier Coefficients of a Derivative
- The Dirichlet and the Féjer Kernel
- Approximation by Trigonometric Polynomials (Quick look at Subsection 6.1.4)
- The Fourier Transform
notes pp. 147–152
also, Krantz Chapter XIII
07 november - Fourier Transform of Gaussians
- Fourier Transform of the Derivative
- The Heat Equation
- Decay of the Fourier Transform at infinity
- The Poisson Kernel
- The Dirichlet Problem in the Disk
notes pp. 152–155
also, Krantz Chapter XIII
08 november - Solution to the Dirichlet Problem in the Disk
- Fourier Series of Sines and Cosines
- The Heat Equation in an Interval:
Separation of Variables and Superposition
- The Heat Equation in \( \mathbb R \). The Heat Kernel
- The Wave Equation. Separation of Variables
notes pp. 156–165
also, Krantz Chapter XIII
14 november - Conclusions for the Wave Equation
- Repetition of Holomorphicity and Harmonicity
- Repetition of Elementary Functions
- Exercises 1.3, 1.5, 1.12, 1.20 in Collection_Exercises_MA2106
notes pp. 165–166
15 november - Exam Preparation
- Exercises 1.14, 1.19, 1.20 in Collection_Exercises_MA2106
- Exercises 1–5 in Prøveeksamen_11Nov24
21 november - Exam Preparation
- Repetition Identity Principles and Cauchy Estimates
- Exercises 6–7 in Prøveeksamen_11Nov24
- Exercise 5 in Prøveeksamen_II_19Nov24
22 november - Exam Preparation
- Repetition Evaluation of Integrals. Fourier Coefficients.
- Exercises 4,6,7 in Prøveeksamen_II_19Nov24
2025-06-19, Carlos Mudarra Diaz Malaguilla