Contact | Description | Topics | Texts | Notes | Lectures | Assessment and Assignments |

mulogo

MAST30026
Metric and Hilbert Spaces

Semester II 2022


Pre-Exam consultation hours of Arun Ram are Monday 31 October 1:30-2:30pm, Wednesday 2 November 1:30-2:30pm and Friday 4 November 1:30-2:30pm.
These will be held in Room G47 in the Peter Hall building.

Proof writing sessions

The exam assesses whether you can write quality solutions to questions in an exam setting. So the main goal of the class is to learn to write quality, well presented solutions, that communicate well and thoroughly to the reader. Whether or not you get a correct answer has much less importance than whether your exposition is of good quality.

To help learn this skill, we will provide three "proof writing" sessions a week, in the same room as the lecture, in the hour before class. These are not required, you decide whether you want to take advantage of this resource or not. It is during these sessions that we will provide models for writing solutions to exam questions. These sessions will be available live streamed and recorded, via the usual Lecture capture.
https://canvas.lms.unimelb.edu.au/courses/129807

  • Sample exam 1
  • Sample exam 2
  • Sample exam 3
  • Sample exam 4 -- Solutions part 1, Solutions part 2.

The goal is to be able to write quality solutions in an exam setting.

Lectures

Lecturer: Arun Ram, 174 Peter Hall, email: aram@unimelb.edu.au

Time and Location: Zoom link on Canvas https://canvas.lms.unimelb.edu.au/courses/129807
       Lecture: Monday 9:00-10:00 Russell Love Theatre, Peter Hall Building,
       Lecture: Wednesday 9:00-10:00 Russell Love Theatre, Peter Hall Building,
       Lecture: Friday 10:00-11:00 Russell Love Theatre, Peter Hall Building,

The lectures will be live streamed by the usual Echo 360/Canvas delivery
If there are no technology glitches, each lecture will also be Zoom recorded and made available on Echo360 (accessible through Canvas) within 7 days after the live lecture. You will do well on the exam if you are able to write solutions in the same model as in the assignment solutions and the proof writing sessions without the need for notes. This is the skill that will be assessed on the exam.


Tutorials

The tutorials will begin on Friday of Week 1 (July 29).
In the first tutorial the "assignment marking exercise groups" will be allocated. If you do not attend the first tutorial the tutor will assign you to a group without your input.

       Practice class: Monday 15:15-16:15 Online, Tutor: Weiying Guo
       Practice class: Wednesday 11:00-12:00 in Peter Hall 213, Tutor: Arun Ram
       Practice class: Friday 11:00-12:00 in Peter Hall 213, Tutor: Arun Ram

  • Tutorial sheet 1: Proof machine, bounded operators and completeness
  • Tutorial sheet 2: Gram-Schmidt and building projections in Hilbert spaces
  • Tutorial sheet 3: Othogonal decomposition, duals and bases
  • Tutorial sheet 4: Spectral theorem
  • Tutorial sheet 5: Cauchy sequences and completions
  • Tutorial sheet 6: Limits, interiors, closure, continuity
  • Tutorial sheet 7: Compactness
  • Tutorial sheet 8: Uniform spaces and Uniform continuity
  • Tutorial sheet 9: Properties of the Real numbers
  • Tutorial sheet 10: Planning the execution of an exam
  • Tutorial sheet 11: Product, quotient and function space topologies

Discussion

A key part of Lecture time is the Ask me a question time. Given that we will hold the "Proof writing workshop" in the hour before lecture these will probably morph into the "Ask me a question" time for the 10 minute slot between class periods. The official lecture starts at 5 min past the hour.

Consultation hours: Arun Ram, Monday-Wednesday 10-11am,

Student Representatives: Haris Rao murao@student.unimelb.edu.au and Jiani Xie jianix1@student.unimelb.edu.au

Facebook group: https://www.facebook.com/groups/????????/ The lecturer and tutors will not be reading, looking at, or participating in the Facebook group. If you wish to have the lecturer or tutors read or participate, hold the discussion on Ed Discussion (which has math equation/LaTeX capability). The Ed Discussion link for this course is available through Canvas. https://canvas.lms.unimelb.edu.au/courses/129807

Methods and mechanics for teaching, and how to improve teaching and learning are topics that I think about quite alot. One piece of writing that I have done on the subject is
Teaching Math in The Next Life
which might also be helpful to students taking this course. Certainly we will discuss many of these topics in class. I would be very grateful for any reactions/thoughts/discussion that you can give me on this writing (and any of the other resources on this page).


Assignments

The homework assignments are at the following links: (total 7% each = 5% for the first submission +2% for the second submission)

  • Assignment 1: Due 11 and 18 August before 4:00pm. Solutions: Question 1, Question 2, Question 3, Question 4A, Question 4B, Question 4D, Question 4E, Question 4F.
  • Assignment 2 (question 5(b) revised 27.08.2002): Due 8 and 15 September before 4:00pm. Solutions: Assignment 2 solutions,
  • Assignment 3: Due 6 and 13 October before 4:00pm, Solutions: Question 1, Question 2, Question 3, Question 4, Question 5.
For each assignment submit your assigment solutions through Canvas/Gradescope before the first deadline and submit the marking exercise before the second deadline.

The first deadline is for you to submit your solutions to the assignment questions. Your submission will be marked by the tutors. The first submission of each assignment is worth 5% of the total mark for the course.

After the first submission you will receive 4 assignments to 'mark' (the submissions of the others in you 'assignment marking group'). Only by reading solutions and trying to do marking yourself, do you learn how to optimise your marks on the exam. Read the solutions, provide feedback, and assign a mark for each question. You may be asked to provide justification for the mark you assign (so keep records of the marking scheme you used for each question). Submit your "marking" of the 4 assignments as the second submission of the assignment. Tutors will allocate marks for your second submission based on how conscientiously you undertake this exercise. The second submission of each assignment is worth 2% of the total mark for the course.

Because the assignment solutions will be released immediately after the due date/time, no late submissions will be accepted. If you miss a submission and you have a valid reason (medical certificate or equivalent), then you will be given the option to recover the marks for that assignment by making 3 distinct handwritten copies of the assignment solutions and one handwritten copy of the sample exam solutions.

It is recommended that you do and submit the assignments in the same way that you will for the exam: handwritten, a new page for each question, very clear exposition so that the marker can follow your argument easily, scanned with Camscanner, and uploaded question by question into Gradescope. One purpose of the assignments is to prepare your exam taking skills.


Assessment

Assessment will be based on three written assignments due at regular intervals during semester amounting to a total of up to 50 pages (20%), and a 3-hour written examination in the examination period (80%).

Almost everybody seems to agree that the "50 pages" doesn't make much sense in our modern technological world where some assignments might even be submitted in video form (the handbook entry has not been changed for more than 10 years) and a better estimate is to note that the handbook entry says that Total time commitment (should average) 170 hours. If we spread this over 14 weeks (12 class and 2 weeks exam study), we get 12.14 hours per week, and then if we subtract the number of class and tutorial hours per week (4) then we get 8.14 hours per week, and if we spread 12 weeks of 8 hours over 3 assignments then we get

4*8.14=32.6, as the average number of hours of study and work to complete each assignment.
If you are spending more time than this, then please contact us immediately so that we can help you to make your study more efficient and effective so that you will be able to complete the necessary work for this class in this expected time commitment timeframe.
If you are spending less time than this, then maybe you should think twice about whether you will do well on the final exam.

The exam assesses whether you can write quality solutions to questions in an exam setting. So the main goal of the class is to learn to write quality, well presented solutions, that communicate well and thoroughly to the reader. Whether or not you get a correct answer has much less importance than whether your exposition is of good quality.

To help learn this skill, we will provide three "proof writing" sessions a week, in the same room as the lecture, in the hour before class. These are not required, you decide whether you want to take advantage of this resource or not. It is during these sessions that we will provide models for writing solutions to exam questions.


Readings

The following notes written by Arun Ram and provide a good pcture of how I think about and work with this subject.

References       Proof machine (How to do proofs)       Vocabulary

Sequences and Series       Limits and Continuity Real numbers
Sets, functions and relations       Orders and fields
Function spaces       Inner products and orthogonality
     
Vector Spaces and Linear transformations       Orthogonality and Projections       Eigenvalues and the spectral theorem
     
Spaces New spaces from old       Limits and Topologies
     
Completions Compact spaces Hausdorff spaces
     
Uniform Spaces Connected vs path connected

Further references for useful comparison/contrast are:

  • Daniel Murfet's MAST30026 page
  • Gerald Teschl, Mathematical Methods in Quantum Mechanics, Graduate Studies in Mathematics, Volume 157, Amer. Math. Soc., Providence, 2014.
  • Baby Rudin: W. Rudin, Principles of Mathematical analysis, McGraw Hill
  • Terry Tao's analysis books
  • Wikipedia

Lectures and Tasks to keep up with the material 2022

The lectures will be recorded, but watching the recorded lectures is NOT an efficient way to succeed in this course. The most efficient way to succeed in this course is to make the ink flow out of the end of your pen in the process of copying solutions and proofs. There are many solutions and proofs provided as examples on this web page and on the web pages for previous times that I have lectured this course.
  • Lecture 1, 25 July 2022: Proof machine
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assignment 1 done. It is due on 11 August, which is just over 2 weeks after the first lecture. Question 1 is a review question from Linear algebra. Carefully, read the notes on proof machine which are at this link Proof Machine Notes and look at some examples from the notes at this link Inner products and Orthogonality notes so that you can write a quality, thorough solution. Do question 1 before Wednesday.


  • Lecture 2, 27 July 2022: Function spaces (i.e. infinite dimensional vector spaces)
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Since you finished question 1 already, do Question 2. Question 2 is a review question about convergence of series from Real Analysis. Look at some examples from the notes at this link Sequences and Series notes so that you can write a quality, thorough solution. Do question 2 before Friday.


  • Lecture 3, 29 July 2022: Bounded linear operators (i.e. linear transformations)
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Since you finished questions 1 and 2 already, do Question 3. Question 3 is a computation question that helps to understand norms of operators. Look at some examples from the notes at this link Function spaces Notes so that you can write a quality, thorough solution. Do question 3 before Monday.


  • Lecture 4, 1 August 2022: ℝ is the completion of ℚ (i.e. What are the real numbers?)
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Since you finished questions 1 and 2 and 3 already, do Question 4 part A. Question 4A requires only basic proof machine and a couple examples of series that are covered in Calculus 2. To review the definition of a subset look at Sets, functions and relations Notes and for the notion of what sup is look at Orders and fields Notes. Do question 4A before Wednesday.


  • Lecture 5, 3 August 2022: Hilbert spaces
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Question 4B requires only basic proof machine and the definitions of limits that are covered in Calculus 2 and Real analysis. For a review of limits look at the notes at the Limits Notes. Do question 4B before Friday.


  • Lecture 6, 5 August 2022: Completions
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Question 4F uses exactly the same technique that was used to prove that ℝ is a completion of ℚ in today's lecture. For a review of Cauchy sequences and completion look at Tutorial Sheet 1. Do question 4F before Monday.


  • Lecture 7, 8 August 2022: Hilbert space duals
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Question 4D uses exactly the same technique that was used to prove that separable Hilbert space is isomorphic to its dual in today's lecture. For a review of this proof see Tutorial Sheet 2 Do question 4D before Wednesday.


  • Lecture 8, 10 August 2022: Orthogonality and projections I
    Handwritten lecture notes

    Student TODO list:
    • The first goal is to get Assigment 1 done. Having done all the other parts of Question 4, Question 4E is quite easy. Finish up the assignment and submit it before 4pm on Thursday.


  • Lecture 9, 12 August 2022: Orthogonality and projections II
    Handwritten lecture notes

    Student TODO list:
    • Take a break over the weekend.


  • Lecture 10, 15 August 2022: Eigenvalues and eigenvectors: compact operators
    Handwritten lecture notes

    Student TODO list:
    • This weeks topic is existence of eigenvectors, thinking through Question 1 on Assignment 1. Carefully copy questions 1, 2 and 4 from Assignment 2 from 2016 and their solutions (which you can get from the 2016 Metric and Hilbert spaces web page. Analyze how these solutions relate to Theorems 16.11, 16.12, 16.13 and 15.14 in the the notes on Eigenvalues and the Spectral theorem.

  • Lecture 11, 17 August 2022: Eigenvalues and eigenvectors: Self adjoint operators
    Handwritten lecture notes

    Student TODO list:
    • We are now exploring the infinite dimensional versions of self adjoint opertors and the spectral theorem. Be sure to carefully review, and recopy by hand the definitions and the proofs so that they are clear in your head, Section 3.11 and 3.12 and Theorems 3.13 and 3.14 in the Linear algebra review notes: Inner Products and Orthogonality.

  • Lecture 12, 19 August 2022: The spectral theorem for compact self adjoint operators
    Handwritten lecture notes

    Student TODO list:
    • I hope everyone had a good weekend and caught up on all your other classes.

  • Lecture 13, 22 August 2022: A final lecture on spectral theorem and norms of operators
    Handwritten lecture notes

    Student TODO list:
    • As we finish up our section on Linear algebra, copy out the problems from the sample exams that focus on linear algebra and do each of them a few times as if you were training for an exam on this material.

  • Lecture 14, 24 August 2022: Limits and neighborhoods
    Handwritten lecture notes

    Student TODO list:
    • Carefully read Limits and Topologies. Do this by FIRST reading the references, then reading SECTION FOUR (i.e. Section 4), then reading section 3, then reading section 2 and then reading section 1.

  • Lecture 15, 26 August 2022: Open, closed and neither -- interior points and close points
    Handwritten lecture notes

    Student TODO list:
    • Now it is time to focus on Assignment 2. Read question 1 and remind yourself what the precise definition of an infinite sum is. Ask yourself where you've seen sums that look like this before. Then put off question 1 and do questions 2 and 3, which are essentially Calculus 2 questions. Finish Questions 2 and 3 by Monday.

  • Lecture 16, 29 August 2022: Close points, cluster points and limit points
    Handwritten lecture notes

    Student TODO list:
    • The priority now is to finish Assignment 2. Do the algebra parts of questions 4 and 5 (namely, both part (c)s of question 4 and parts (b) and (c) of Question 5. Get these done by Wednesday.

  • Lecture 17, 31 August 2022: Hausdorff spaces: Uniqueness of limits
    Handwritten lecture notes

    Student TODO list:
    • The priority now is to finish Assignment 2. Do the graphing and integration parts of questions 4 (namely, parts (a), (b), (d) and (e). Get these done by Friday.

  • Lecture 18, 2 September 2022: New topological spaces from old
    Handwritten lecture notes

    Student TODO list:
    • The priority now is to finish Assignment 2. Do the rest of questions 4 and 5 (namely, part (f) of question 4 and parts (a), (c) and (e) of question 5. Get these done by Monday.

  • Lecture 19, 5 September 2022: Compact spaces: Existence of limits
    Handwritten lecture notes

    Student TODO list:
    • The priority now is to finish Assignment 2. Only one question left, which is question 1. It might help to review the proof of Theorem 22.5 in Tutorial sheet 2: (and other results on this tutorial sheet) to knock this off. Get this question done by Wednesday and submit the assignment in GRADESCOPE.

  • Lecture 20, 7 September 2022: Compactness: Existence of cluster points
    Handwritten lecture notes

    Student TODO list:
    • The reading for this section is the notes on Compact spaces. Review these carefully. Show that z is not a cluster point of a sequence (a1, a2, ...) if and only if there exists Bε(z) such that Bε(z) ∩ (a1, a2, ...) is finite.

  • Lecture 21, 9 September 2022: Uniform convergence and pointwise convergence
    Handwritten lecture notes

    Student TODO list:
    • Spend time on your other classes this weekend. Start making vocabulary flash cards for this course to work through with friends, relative, acquaintances and random people that you meet on public transport.

  • Lecture 22, 12 September 2022: Uniform spaces and uniform continuity
    Handwritten lecture notes

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Do parts (a) and (c) of Question 1 before Wednesday. Spend any extra time you have working on your vocabulary flash cards.

  • Lecture 23, 14 September 2022: Uniform spaces as a category
    Handwritten lecture notes

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Do part (b) of Question 1 and part (a) of Question 2 before Friday. Spend any extra time you have working on your vocabulary flash cards.

  • Lecture 24, 16 September 2022: Connected sets in ℝ
    Handwritten lecture notes

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Do parts (b), (e) and (f) of Question 2 and part (a) of Question 3 and part (c) of Question 2 and part (b) of Question 3 before Monday. Spend any extra time you have working on your vocabulary flash cards.

  • Lecture 25, 19 September 2022: Real numbers, p-adic numbers and formal power series
    Handwritten lecture notes

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Do parts (a), (b) (c) of Question 4 and part (d) of Question 2 before Wednesday. Spend any extra time you have working on your vocabulary flash cards.

  • Lecture 26, 21 September 2022: The compact-open topology, path spaces, fundamental groups, and connectedness
    Handwritten lecture notes

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Do part (d) of Question 4 and start on Question 5 before Friday. Spend any extra time you have working on your vocabulary flash cards.

  • Lecture 27, 23 September 2022: Grand Final Eve, NO CLASS

    Student TODO list:
    • It is a good idea to get Assignment 3 done before the midsemester break. Finish Question 5 before the game. Spend any extra time you have working on and rewriting your vocabulary flash cards over and over again.

  • MIDSEMESTER BREAK

    Student TODO list:
    • Spend any extra time you have working on and rewriting your vocabulary flash cards over and over again.

  • Lecture 28, 3 October 2022: The intermediate value theorem, the mean value theorem and Taylor's theorem
    Handwritten lecture notes

    Student TODO list:
    • Now it is time to intensively start preparing for the Exam. Make a sample exam just using Tutorial sheets 1 and 2 and 3. Make questions that look like the questions on the sample exams. Do this by Wednesday.

  • Lecture 29, 5 October 2022: Properties of the real numbers
    Handwritten lecture notes

    Student TODO list:
    • Now it is time to intensively start preparing for the Exam. Trade sample exams (from Tutorial sheets 1, 2 and 3) that you made with a friend, and do each other's exam and then mark your friend's work on your exam and discuss with them how you can optimize your marks next time. Do this by Friday.

  • Lecture 30, 7 October 2022: Limits via filters
    Handwritten lecture notes

    Student TODO list:
    • Do sample exam 4 over the weekend. Give yourself a 4 hour block and allow yourself notes, but don't allow yourself to go overtime. Mark your own work after you are done.

  • Lecture 31, 10 October 2022: Revisiting dual spaces
    Handwritten lecture notes

    Student TODO list:
    • Make a sample exam just using Tutorial sheets 4 and 5 and 6. Make questions that look like the questions on the sample exams. Do this by Wednesday.

  • Lecture 32, 12 October 2022: Compactness: training exercises
    Handwritten lecture notes

    Student TODO list:
    • Now it is time to intensively start preparing for the Exam. Trade sample exams (from Tutorials 4, 5 and 6) that you made with a friend, and do each other's exam and then mark your friend's work on your exam and discuss with them how you can optimize your marks next time. Do this by Friday.

  • Lecture 33, 14 October 2022: Generating topologies
    Handwritten lecture notes

    Student TODO list:
    • Do sample exam 4 over the weekend, the same one that you did last weekend. This time only give yourself a 3 hour block and do not allow yourself notes. Mark your own work after you are done.



  • Lecture 34, 17 October 2022: Subspaces of ℝ∞
    Handwritten lecture notes
  • Lecture 35, 19 October 2022: Measures and Integration
    Handwritten lecture notes
  • Lecture 36, 21 October 2022: Dual spaces revisited
    Handwritten lecture notes Typewritten lecture notes


Thoughts and advice

  • The expectation is that the final exam will be 3 hours, IN PERSON, no additional notes allowed. If this changes we will make an announcement of the change. Unless you can find some announcement changing this plan on this webpage and on Canvas, prepare for the case that no additional notes will be allowed on the exam.
  • Just as a carpenter without a hammer is mostly useless, a mathematician without a good place to work is mostly useless.
  • Tips for time management:
    • It is much easier (and safer) to run 45 min per day to attain 6 hours in a week and 24 hours in 4 weeks, than to run for 24 hours solid every fourth week on Sunday.
    • To actually run 45 min, it takes me at least 15 min to psyche myself up and convince myself that it is actually not raining and so therefore I should go running, and after a 45 min run I always walk for 5 min and I always go home and have a glass of milk and tell my wife (at length) how cool I am for running 45 min per day. All in all, I waste a good 40 min when I go running for 45 min. If I were more efficient (and every so often, but rarely, I am) then it would only takes me 50 min.
    • Measurement of time is a tricky thing and requires real discipline. Teaching and research faculty at University of Melbourne recently had to complete a survey on distribution of their time on the various activities of the job: Do I count the 6 times I had to go check my email and the weather and my iPhone in the time that I spend preparing my Metric and Hilbert Spaces lecture?
  • Tips for exam preparation:
    • The time that a 100m olympic runner (who wins a medal) is actually competing at the olympics is say (5 heats, 7sec each) 40 seconds. Successful performance during these 40 sec is impossible without adequate preparation.
    • The time that a Metric and Hilbert spaces student spends on the final exam is 3 hours. Sucessful performance during these 3 hours is .....
  • Prof. Ram reads email but generally does not respond by email. Usually these are collated and reponses to email queries are provided in the first few minutes of lectures. That way all students can benefit from the answer to the query.

Feedback

If you don't communicate with us, then we can't help you. We'll do our best, but it is much easier if you take some responsibility too by asking questions and communicating in class and in tutorial.


Problem sheets

As explained in the writing
Teaching Math in The Next Life,
almost certainly, I will build the exam by choosing the questions randomly from my problem lists for the course. These problem lists for this course are the following.

  • Problem sheet: Spaces
  • Problem sheet: New Spaces from Old
  • Problem sheet: Closure, continuity, and limits
  • Problem sheet: Function spaces
  • Problem sheet: Compactness
  • Problem sheet: Vector spaces with Topology

Subject Overview

The handbook entry for this course is at https://handbook.unimelb.edu.au/2022/subjects/mast30026. The subject overview that one finds there:

This subject provides a basis for further studies in modern analysis, geometry, topology, differential equations and quantum mechanics.It introduces the idea of a metric space with a general distance function, and the resulting concepts of convergence, continuity, completeness, compactness and connectedness. The subject also introduces Hilbert spaces: infinite dimensional vector spaces (typically function spaces) equipped with an inner product that allows geometric ideas to be used to study these spaces and linear maps between them.

Topics include: metric and normed spaces, limits of sequences, open and closed sets, continuity, topological properties, compactness, connectedness; Cauchy sequences, completeness, contraction mapping theorem; Hilbert spaces, orthonormal systems, bounded linear operators and functionals, applications.


Main Topics

  • (1) Infinite dimensional vector spaces
  • (2) Norms and distances
  • (3) Inner products and orthogonality
  • (4) Bounded and compact linear operators
  • (5) The spectral theorem
  • (6) Metric spaces, uniform spaces and Topological spaces
  • (7) Limits, closure, continuity
  • (8) Hausdorff and compact spaces
  • (9) Cauchy sequences and completions
  • (10) Connectedness and compactness for subsets of ℝn
  • (11) Product topologies, quotient topologies and function space topologies
  • (12) Connections to probability and physics