Jumpstart - Analysis for Graduate School

Introduction

The successful graduate student exhibits a pro-active and inquisitive attitude towards learning and possesses or can develop an ability to self-assess and identify and solve his or her own weaknesses and shortcomings in arguments, ideas, and proofs. Some students have these traits, some can develop them with training and dedication, while, for others, they remain elusive.
While much of the material of these lectures is presented at American undergraduate institutions, most students merely make a superficial acquaintance with the central concepts of analysis. It is paramount to gain a deeper understanding of them in order to be well-equipped to sail smoothly through graduate school. The emphasis is really on developing an ability to do and solve rather than to know. According to Lloyd Alexander We learn more by looking for the answer to a question and not finding it than we do from learning the answer itself. You are invited to figure things out for yourself: graduate school does not merely consists in extending your knowledge of facts, but, rather, in a mathematical growth driven by understanding. The latter can only be achieved by personally engaging in the thought process. It is not enough to sit at the receiving end and collect mathematical facts. Like sports or music, mathematics requires constant mindful practice for skills to develop. This can only be done if one cares about going to the bottom of things, about developing one's own understanding, and about investigating the multifaceted beauty of mathematical objects and concepts. A graduate degree is not something that can be given to you, but something you can become if you allow yourself the possibility of failing and enjoy the pleasure of exploring new territory while developing the necessary tools to conquer it.
Every lecture of this course opens with a hidden (until you click on it) motivating paragraph which aims at providing a broader perspective pointing to a choice of good reasons why a given topic is important. The main thread of the lectures is quite standard and takes you through a selection of important concepts and results with focus on mathematical rigor. Occasionally formal rigor is temporarily suspended to provide a word of intuition. Mathematics is, after all, often an exercise in translating raw intuition into rigorous, solid, and verifiable arguments. In order to gain a really useful understanding, you will need to develop your own personal intuition. The fact that proofs are hidden (but become available upon clicking) is to be considered an invitation to try and give your own proof before even reading the one provided. Even after reading our proof, you are encouraged to hide it again and try carrying it out on your own. In so doing, you will be able to verify whether you merely followed its logical steps or you really understood its idea, in which case you would be able to reproduce it. With persistence and time you will inevitably develop your own proof and mathematical thought skills. Not only will you be able to reproduce proofs but also propose your own. As an added benefit, you will understand the boundary of validity of results as you will be confronted with the task of identifying necessary and sufficient conditions. Examples play a crucial role in testing the range of validity of your mathematical beliefs and in developing an intuition for abstract concepts, which are often born out of example. One of my teachers invited students to always try and find the simplest non-trivial example.
Mathematics requires both "computational power" and "abstract processing, structuring, and pattern recognition prowess". In this sense the exercises and problems in the lectures are not only "an hour spent in the gym" but also an invitation to reflect on important concepts, their limits, and their relationships.
The final goal is not to have mnemonic access to mathematical facts but rather to make sense of reality by using mathematics, to develop your own mathematical worldview.
Learning with understanding usually happens in tandem with growth, which only occurs in response to a mindful effort. While the first step towards a deep understanding is the ability to reproduce an argument (beyond mere mnemonic recall), the ultimate goal is the development of your own argument. Hence the importance of not simply moving on after reading a proof and following all of its steps, but to verify whether you are capable of, at first, reproducing it, and, with time, to simply "see it" and thus even be able to give alternative proofs. It is often easy (and misleading) to "get the rhyme but not the reason"!
Remember: there are many explanations for just about any interesting mathematical fact, but the best of them all is always YOURS! Never call it quits before you find it. Enjoy the journey!

User's Guide

Lectures

The lectures are structured as follows. They always open with a motivating paragraph which we ecourage you to read if you are wondering why at all to even consider the topic of the lecture. You can then quickly read through a lecture to obtain an overview of the material. On a second reading you are encouraged to attempt solving the given exercises and examples in preparation for a better understanding of the results presented. Finally you should try and give your own proof of the results, read and understand the one(s) given, and eventually, try to reproduce it(them), or complete your own, if you were not able to finalize your first attempt. At this point you are ready to take on the corresponding weekly problem sets. You can use the submit a question link in the contact menu to send us questions/comments about the material covered. Please make extensive use of it as your inquiry will, of course, be addressed, while, simultaneously, allowing us to improve the notes over time. Answers to recurring issues will be integrated into the lecture notes.

Assignments

A weekly homework set will be assigned with the given due date. Please turn in your solutions in latex format by using this template replacing Fname and Lname with your first and last names and n with the homework number. You can simply follow the instructions given in the file itself in the areas commented out. If you don't have a LaTex distribution on your computer, we suggest that you download and install some version of it. Recommended choices are
MacTex for Apple computers running Mac OS X.
MikTex for computers running MS Windows.
The LaTex Project for computers running any operating system or if you prefer not to download LaTex onto your computer and use an online LaTex typesetting platform such as Overleaf instead. Notice that UCI has an institutional subscription to Overleaf and the platform is therefore available to your for free.

Questions and Answers

In order to foster interaction and participation, you are asked to submit at least one written question each week about the material covered in the week's lectures and to answer one of the questions posted by one of your peers. For this purpose we will use a common Overleaf file, where the questions and answers will appear and where everybody can leave their comments, share their ideas, and suggest topics of discussion. Particularly enlightening questions and answers will eventually be posted on this website.

Videos

Videos are intended to give you a brief introduction to important aspects of the topics covered in the lectures. They should not be used as a replacement of the notes but rather as an additional motivation to dwell deeper on the topics. Notice that they do not cover all the material included in the corresponding lecture.

Disclaimer

These notes are the fruit of the combined effort of Patrick Guidotti and Song-Ying Li. In spite of our attempt to keep the lectures error and misprint free, there will inevitably be some that we overlooked. If you identify any, we kindly ask you to let us know by using the emailing link available in the top menu under contact. This introduction, the motivational paragraphs at the beginning of the lectures, and the videos reflect the "taste" and choices of the first author and are solely his responsibility.