Algebraic Geometry III/IV

Lecturer : Thanasis Bouganis

Office : CM 126A

Ofiice Hours: Mondays 14:30 to 15:30 (or just write me an e-mail)

E-mail : athanasios.bouganis@durham.ac.uk

Term : Michaelmas 2013

Lectures :
  • Wednesdays, 11:00 in CM107
  • Thursdays, 9:00 in CM107

Literature

The lecture is based on the following two books. Although we will not follow them strictly, the material can be found in them and they may sometimes offer a different approach to the material.

Relevant Books:
  • M. Reid, Undergraduate Algebraic Geometry, LMS Student Texts 12, Cambridge 1988.
  • F. Kirwan, Complex Algebraic Curves, LMS Student Texts 23, Cambridge 1992.

4H reading material: Affine Varieties and the Nullstellensatz (Chapter II, paragraph 3 of Miles Reid's "Undergraduate Algebraic Geometry")

Problem Sheets:

Problem Sheet 1 (due: Thursday Oct 24 at the beginning of the lecture)

Solutions to Problem Sheet 1

Problem Sheet 2 (due: Friday Nov 8, at 16:00, folder on my office door)

Solutions to Problem Sheet 2

Problem Sheet 3 (due: Friday Nov 22, at 16:00, folder on my office door)

Solutions to Problem Sheet 3

Problem Sheet 4 (due: Friday Dec 6, at 16:00, folder on my office door)

Solutions to Problem Sheet 4

Content of Lectures

Date Content
Wednesday, 9 October 2013 (Week 1) Introduction to algebraic geometry, definition of affine algberaic plane curves, Polynomial rings.
Thursday, 10 October 2013 (Week 1) homogeneous polynomials in two variables, factorisation of homogeneous poynomials, irreducible components of curves, singularities.
Wednesday, 16 October 2013 (Week 2) minimal polynomials, Study's Lemma (without proof), multiplicity of a point, tangent lines at a point.
Thursday, 17 October 2013 (Week 2) Examples of points with multiplicities, geometric explanation of the tangent line at a non-singular point using the implicit function theorem, definition of projective spaces and basic properties.
Wednesday, 23 October 2013 (Week 3) Properties of projective spaces, definition of complex projective curves,
Thursday, 24 October 2013 (Week 3) notions of singular and non-singular points for projective curves, relation between affine and projective curves.
Wednesday, 30 October 2013 (Week 4) irreducibility and singularity for projective and affine curves, Euler's Relation, examples of singular projective curves with an non-singular affine part.
Thursday, 31 October 2013 (Week 4) Exercise Class.
Wednesday, 6 November 2013 (Week 5) Bezout's Theorem (statement), definition of the resultant of two polynomials, properties of resultants.
Thursday, 7 November 2013 (Week 5) properties of resultants (ctd), the degree of the resultant, other forms of the resultant
Wednesday, 13 November 2013 (Week 6) other forms of the resultant (ctd), the notion of the projective transformation, applications of resultants: non-emptyness of the intersection of two projective curves .
Thursday, 14 November 2013 (Week 6) the Weak Bezout's Theorem, finiteness of the singular locus of an irreducible projective curve
Wednesday, 20 November 2013 (Week 7) the notion of intersection multiplicity, defining properties of the intersection multiplicity, existence of the intersection multiplicity.
Thursday, 21 November 2013 (Week 7) uniqueness of the intersection multiplicity,
Wednesday, 27 November 2013 (Week 8) uniqueness of the intersection multiplicity (ctd), proof of Bezout's Theorem, singularities and multiplicities
Thursday, 28 November 2013 (Week 8) Exercise Class.
Wednesday, 04 December 2013 (Week 9) Singularities and intersection multiplicities (ctd), intersection multiplicities equal to one and examples, introduction to cubics, the Hessian of a polynomial and points of inflection
Thursday, 05 December 2013 (Week 9) Properties of the Hessian of a polynomial, existence of and bounds on the number of points of inflection of a non-singular projective curve, classification of projective non-singular cubic curves
Wednesday, 11 December 2013 (Week 10) classification of projective non-singular cubic curves (ctd), intersections of lines and non-singular cubics
Thursday, 12 December 2013 (Week 10) the abelian group structure on points of non-singular projective cubics