MA40188 Algebraic Curves

2015/16 Semester 1

Unit Description
Lectures and Office Hours
Recommended Texts
Course Calendar
Exercise Sheets Exam Information

Unit Description

This unit provides an introduction to algebraic geometry for students who have some background of abstract algebra. You should have taken Algebra 2B (MA20217 or equivalent) before taking this unit. Some familiarity of the theory of rings and fields will be assumed. See recommended texts for lecture notes of Algebra 2B in the last two years. You should also be comfortable with reading and writing rigorous mathematical proofs.

We will cover the following topics in this unit: affine algebraic sets (the ideals of affine algebraic sets, functions on affine algebraic sets, maps between affine algebraic sets), projective algebraic sets (the ideals of projective algebraic sets, functions on projective algebraic sets, maps between projective algebraic sets), examples of algebraic curves and algebraic surfaces in low degrees.

Here is the syllabus on the Unit Catalogue. A handout on course information is given out in the first lecture.

Lectures and Office Hours

The class meets three times a week. In general, Monday and Friday morning lectures are devoted to introducing new material, while the exercise classes on Friday afternoons will mainly focus on problem solving. See course calendar for more details on the contents of each lecture.

Your lecturer for this unit is Dr. Ziyu Zhang. You can contact me by email at zz505 at Bath for any questions or concerns. I hold two office hour sessions each week. You are welcome to come and ask questions at any time during the sessions. If you have questions to ask but cannot make to the office hours, please feel free to contact me.

There will be extra office hours after the Christmas vacation. Please see exam information.


Monday
Tuesday
Wednesday Thursday Friday
10:15-11:05
Lecture
3E 2.4




11:15-12:05




Lecture
3E 2.4
16:30-17:30
Office Hour
4W 4.8


Office Hour
4W 4.8

17:15-18:05




Exercises
3E 2.4


Recommended Texts

The lectures do not closely follow any particular textbook. However the following two books cover most of the topics that we are discussing.
  • Reid, Miles. Undergraduate algebraic geometry. London Mathematical Society Student Text, 12. Cambridge University Press, Cambridge, 1988. ISBN: 0-521-35662-8. The online access of this book is provided by the university library.
  • Fulton, William. Algebraic curves -- An introduction to algebraic geometry. Advanced Book Classics. Addison-Wesley Publishing Company, Redwood City, CA, 1989. ISBN: 0-201-51010-3. The author has made this book freely available to anyone through his webpage.
Hard copies of both books are also available in the library. There are also many other good books which are relevant to this unit; see for instance here or here.

For your reference, here are the lecture notes of Algebra 2B (MA20217) used in the past two years.

Course Calendar

More than any other discipline, mathematics requires that a student understands one concept before moving on to the next. Therefore it is critical that you attend this class on a regular basis in order to stay on track with the material we cover. Brief lecture notes will be available here usually after each lecture for your convenience. Although these notes roughly reflect what is being discussed in lectures, reading these notes cannot replace attending lectures yourself.

Here is a complete set of lecture notes, exercise sheets and solutions in one file. It comes in two different versions:

  • Here is a long version: 115 pages. The notes for individual lectures were extracted from this version. It has a table of contents. You can use the clickable cross-reference links to jump back and forth. This version is more suitable for reading on a screen.
  • Here is a short version: 70 pages. The table of contents and large chunks of blank spaces are removed. The font and page margins are smaller. Cross-reference links are also clickable. This version is more economic for printing purpose.

The following is a course calendar, including lecture notes for each individual lecture and handouts distributed in lectures.

Week 1
28/09
Welcome. Affine spaces and affine algebraic sets. Course information.
Notes
02/10 Noetherian rings and Hilbert basis theorem.
Notes
02/10
Brief review of Algebra 2B.
Notes
Week 2
05/10
Nullstellensatz. Notes
09/10
Prime ideals and maximal ideals.
Notes
09/10
Discussion of Exercise Sheet 1.

Week 3
12/10
Coordinate rings and polynomial maps.
Notes
16/10
Homomorphisms of coordinate rings.
Notes
16/10
Discussion of Exercise Sheet 2.

Week 4
19/10
Projective spaces.
Notes
23/10
Projective algebraic sets. Informal questionnaire. Notes
23/10
Discussion of Exercise Sheet 3.

Week 5
26/10
Rational maps.
Notes
30/10
Dominant rational maps and birational maps. Feedback for questionnaire. Notes
30/10
Discussion of Exercise Sheet 4.

Week 6
02/11
Bridge between affine and projective varieties.
Notes
06/11
Rational functions and function fields. Summary of last lecture.
Notes
06/11
Discussion of Exercise Sheet 5.
Week 7
09/11
Non-singularity of irreducible hypersurfaces.
Notes
13/11
Non-singularity of varieties.
Notes
13/11
Discussion of Exercise Sheet 6.
Week 8
16/11
Lines and conics, Bézout's theorem.
Notes
20/11
Cubic curves.
Notes
20/11
Discussion of Exercise Sheet 7.
Week 9
23/11
The group law on non-singular cubics.
Notes
27/11
Linear systems and associativity. Picture in the proof of associativity.
Notes
27/11
Discussion of Exercise Sheet 8.
Week 10
30/11
Planes and quadric surfaces.
Notes
04/12
Non-singular cubic surfaces and 27 lines.
Notes
04/12
Discussion of Exercise Sheet 9.
Week 11
07/12
Brief review. Discussion of Exercise Sheet 10. Exam information.

11/12
(Non-examinable lecture) Non-singular quartic surfaces: K3 surfaces.

11/12
No class.


Exercise Sheets

There will be 10 exercise sheets in total. Every exercise sheet contains 4 problems, most of which have multiple questions. These problems are usually given in increasing difficulty, with the first one involving routine questions and the last one comprehensive and sometimes slightly challenging. Explicit examples are heavily emphasized. Exercise sheets are designed to reinforce concepts covered in lecture as well as to encourage students to explore implications of the results discussed in class. Very few students will be able to go through the entire course without struggling on some problems, so do not be discouraged if you do not immediately know how to solve a problem. In confronting difficult questions you should consider how the problem at hand connects to topics, definitions and/or theorems discussed in class.

Although it is not mandatory to submit your work on a regular basis, it is strongly recommended that your try to work as much as possible on the exercises. If you have worked on a problem for a while and remain stuck, you are encouraged to discuss it with one another, or ask me for hints.  However if you have taken notes while discussing exercises with classmates, it will be a good idea to put these notes away when writing your own solution. Be warned: watching someone else solve a problem will not make exercises a good preparation for your exam. Writing down your own solution will help you think through the material and get a better understanding.

Exercise sheets are usually handed out on Monday and discussed in the exercise class on Friday of the following week. You are warmly welcome to submit your solutions for correction at the end of the exercise class, or anytime earlier. Please write your solutions neatly, with enough justification in each step. Don't forget to write your full name on your work. If it contains multiple pages, it will be helpful if you staple them before submission. At least two problems will be marked every week, but you should treat all four problems equally important. Submitted work will be handed back to you in the week after the deadline. Brief solutions will be posted here shortly after the exercise class.

Exercises Due Date
Hints
Solutions
Sheet 1
09/10
Hints 1
Solutions 1
Sheet 2
16/10
Hints 2
Solutions 2
Sheet 3 23/10
Hints 3
Solutions 3
Sheet 4 30/10
Hints 4
Solutions 4
Sheet 5 06/11
Hints 5
Solutions 5
Sheet 6 13/11
Hints 6
Solutions 6
Sheet 7
20/11
Hints 7
Solutions 7
Sheet 8 27/11
Hints 8
Solutions 8
Sheet 9
04/12
Hints 9
Solutions 9
Sheet 10 N/A
Hints 10
Solutions 10


Exam Information

Here is a mock exam paper and a few old exam papers for your preparation of the exam. Notice that the syllabus for this unit has minor changes every year, so please read the extra remarks for each exam paper to find out questions you don't need to worry about and notations that were used differently.

Questions
Solutions
Remarks
Mock Exam
Solutions
N/A
Exam 2014
Solution 2014
Remark 2014
Exam 2012
Solution 2012 Remark 2012
Exam 2010
Solution 2010 Remark 2010
Exam 2009
Solution 2009 Remark 2009
Exam 2007
Solution 2007 Remark 2007
Exam 2005
Solution 2005 Remark 2005


Here is an exam information sheet, which should give you a rough idea what types of questions you can expect in the exam.

For the convenience of your exam preparation, extra office hours will be provided after the Christmas vacation, until the day of the exam. See the following chart for details. The office hour on Sunday 17th January will take place in the lobby area outside the department office.


Monday
Tuesday
Wednesday
Thursday
Friday
Saturday Sunday
Week of
4th-10th January

Office Hour
4W 4.8
16:30-17:30


Q & A
3E 2.4
11:15-12:05


Week of
11th-17th January
Office Hour
4W 4.8
16:30-17:30

Office Hour
4W 4.8
16:30-17:30

Office Hour
4W 4.8
16:30-17:30

Office Hour
4W Level 2
15:00-16:00
Week of
18th-24th January
Office Hour
4W 4.8
15:00-16:00







Please feel free to contact me if you have questions at any time. Good luck with your exams!

Here is the exam feedback which contains some general comments and common mistakes.


Department of Mathematical Sciences. University of Bath.
Maintained by Ziyu Zhang. Last update on Tuesday, 9 February 2016.