Recent posts

Posts sorted by last_modified_at (most recently updated first).

Linear Systems

Math / Algebraic Varieties

Complete linear systems, base loci, and ampleness

Divisors

Math / Algebraic Varieties

Weil divisors, Cartier divisors, and divisor class groups

Grassmannians

Math / Algebraic Varieties

Grassmannians as parameter spaces of linear subspaces

Dimension

Math / Algebraic Varieties

Dimension of algebraic varieties

Rational Maps

Math / Algebraic Varieties

Rational maps and birational equivalence

Cohomology

Math / Algebraic Topology

Homology

Math / Algebraic Topology

Definition and Properties of Simplices

Homotopy

Math / Algebraic Topology

Projective Varieties

Math / Algebraic Varieties

Projective varieties and homogeneous coordinates

Abelian Groups

Math / Algebraic Structures

Free abelian group, tensor product

Field of Fractions

Math / Algebraic Structures

Localization, ring of fraction, prime ideal

Free Products

Math / Algebraic Structures

Free product and universal property

Grothendieck Groups

Math / Algebraic Structures

The Grothendieck group and the definition of integers

Group Actions

Math / Algebraic Structures

Group action

Group Homomorphisms

Math / Algebraic Structures

Definition and properties of group homomorphisms, kernels and images

Modules

Math / Algebraic Structures

Definition of module

Quotient Groups

Math / Algebraic Structures

Normal subgroups and quotient groups

Restricted Sums

Math / Algebraic Structures

Restricted sum of groups

Definition of Rings

Math / Algebraic Structures

Definition and basic properties of rings

Directed Sets

Math / Set Theory

Directed sets and lattices

Limits

Math / Set Theory

Inverse limit and direct limit

Monotone Functions

Math / Set Theory

Operations on ordered sets and monotone functions

Operations on Functions

Math / Set Theory

Inverse and composition of functions, surjective and injective functions

Axiom of Choice

Math / Set Theory

The axiom of choice and its equivalents

Binary Relations

Math / Set Theory

Definition of Binary Relation