This minicourse is designed as a foundational gateway into the world of Projective Algebraic Geometry. Through the study of conics—the simplest yet most profound examples of algebraic curves—students will transition from classical Euclidean intuition to the powerful methods of modern geometry.
The primary objective is to equip students with the tools to classify conics across different settings: affine, projective, and over various algebraic fields. We will explore the deep interplay between linear algebra (bilinear forms and symmetric matrices) and geometry, culminating in an introduction to the Zaraki topology and the study of families of conics (pencils).
By the end of the course, participants will understand how these classical objects serve as a cornerstone for contemporary research in higher-dimensional algebraic varieties.
Key Learning Objectives:
Mastering homogeneous coordinates and the structure of the projective plane.
Understanding the transition from affine equations to projective varieties.
Analyzing the parameter space of conics and its degenerations.
Field: Projective Geometry / Algebraic Geometry
Prerequisites: Linear Algebra, Basic Analytical Geometry
Description: This course introduces the geometric and algebraic theory of conics, covering their classification, their relationship with projective structures, and their role in contemporary research.
Contents:
Affine and projective conics.
Homogeneous coordinates, symmetric matrices, and bilinear forms.
Pencils of conics and degenerations.
Construction of the group of a conic.
Course Notes (Link)
Course Syllabus
Session 1: Classifying Affine Conics
1.1. Algebraic Systems of Equations
1.2. Solving Systems of Equations: Parameterization
1.3. Algebraic Equivalence: Invariance
1.4. Classifying Affine Conics
1.5. The Group of an Affine Conic
Session 2: Classifying Projective Conics
2.1. Projective Space
2.2. Projective Varieties
2.3. Classifying Conics over Fields with $\text{char}(k) \neq 2$
2.4. The Matrix Associated with a Conic
Session 3: Families of Conics
3.1. Zariski Topology
3.2. The Parameter Space of Conics
3.3. Pencils of Conics
Organized by the DelTaMat project formed Jimmy Santamaria and Charlie Lozano at Universidad Mayor de San Andrés, this two-week course serves as an introduction to algebraic geometry through the study of affine algebraic curves. In the first week, we will explore the category of algebraic sets, laying the foundation for understanding their structure. The second week will focus on plane curves, examining their fundamental properties and key examples.
The course is designed for students interested in developing a geometric intuition for algebraic varieties in a basic level.
Week 1: The Category of affine algebraic sets
Affine algebraic sets (Notes)
Structure of affine algebraic sets (Notes)
Morphisms between affine algebraic sets (Notes)
Topology and Localization of Rings (Notes)
Problems of the first week (Problem Set)
Week 2: Plane Curves and their properties
Plane curves
Multiple points
Local nature of multiplicity
Intersection number
Test