Learn · Basic Algebraic Geometry : Varieties, Morphisms, Local Rings, Function Fields and Nonsingularity
Lecture 25 of 40Unit 10: Graded Rings, Homogeneous Ideals and Homogeneous Localisation
Expanding the Category of Varieties to Include Projective and Quasi-Projective Varieties
Dr. T.E. Venkata Balaji · IIT Madras
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- Basic Algebraic Geometry : Varieties, Morphisms, Local Rings, Function Fields and Nonsingularity, IIT Madras (at NPTEL)
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- CC BY-NC-SA, as NPTEL states it. Non-commercial use only.
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- NPTEL states: "Distributed under Creative Commons Attribution-ShareAlike / CC BY - NC - SA", beside a BY-NC-SA badge.
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All the lectures
- What is Algebraic Geometry?
- The Zariski Topology and Affine Space
- Going back and forth between subsets and ideals
- Irreducibility in the Zariski Topology
- Irreducible Closed Subsets Correspond to Ideals Whose Radicals are Prime
- Understanding the Zariski Topology on the Affine Line; The Noetherian property in Topology and in Algebra
- Basic Algebraic Geometry : Varieties, Morphisms, Local Rings, Function Fields and Nonsingularity
- Topological Dimension, Krull Dimension and Heights of Prime Ideals
- The Ring of Polynomial Functions on an Affine Variety
- Geometric Hypersurfaces are Precisely Algebraic Hypersurfaces
- Why Should We Study Affine Coordinate Rings of Functions on Affine Varieties ?
- Capturing an Affine Variety Topologically From the Maximal Spectrum of its Ring of Functions
- Analyzing Open Sets and Basic Open Sets for the Zariski Topology
- The Ring of Functions on a Basic Open Set in the Zariski Topology
- Quasi-Compactness in the Zariski Topology; Regularity of a Function at a point of an Affine Variety
- What is a Global Regular Function on a Quasi-Affine Variety?
- Characterizing Affine Varieties; Defining Morphisms between Affine or Quasi-Affine Varieties
- Translating Morphisms into Affines as k-Algebra maps and the Grand Hilbert Nullstellensatz
- Morphisms into an Affine Correspond to k-Algebra Homomorphisms from its Coordinate Ring of Functions
- The Coordinate Ring of an Affine Variety Determines the Affine Variety and is Intrinsic to it
- Automorphisms of Affine Spaces and of Polynomial Rings - The Jacobian Conjecture; The Punctured Plane is Not Affine
- The Various Avatars of Projective n-space
- Gluing (n+1) copies of Affine n-Space to Produce Projective n-space in Topology, Manifold Theory and Algebraic Geometry; The Key to the Definition of a Homogeneous Ideal
- Translating Projective Geometry into Graded Rings and Homogeneous Ideals
- Expanding the Category of Varieties to Include Projective and Quasi-Projective Varieties
- Translating Homogeneous Localisation into Geometry and Back
- Adding a Variable is Undone by Homogenous Localization - What is the Geometric Significance of this Algebraic Fact ?
- Doing Calculus Without Limits in Geometry ?
- The Birth of Local Rings in Geometry and in Algebra
- The Formula for the Local Ring at a Point of a Projective Variety Or Playing with Localisations, Quotients, Homogenisation and Dehomogenisation !
- Global Regular Functions on Projective Varieties are Simply the Constants
- The d-Uple Embedding and the Non-Intrinsic Nature of the Homogeneous Coordinate Ring of a Projective Variety
- The Importance of Local Rings - A Morphism is an Isomorphism if it is a Homeomorphism and Induces Isomorphisms at the Level of Local Rings
- The Importance of Local Rings - A Rational Function in Every Local Ring is Globally Regular
- Geometric Meaning of Isomorphism of Local Rings - Local Rings are Almost Global
- Local Ring Isomorphism,Equals Function Field Isomorphism, Equals Birationality
- Why Local Rings Provide Calculus Without Limits for Algebraic Geometry Pun Intended!
- How Local Rings Detect Smoothness or Nonsingularity in Algebraic Geometry
- Any Variety is a Smooth Manifold with or without Non-Smooth Boundary
- Any Variety is a Smooth Hypersurface On an Open Dense Subset