nLab projective cover

Contents

Context

Category theory

Homological algebra

homological algebra

(also nonabelian homological algebra)

Introduction

Context

Basic definitions

Stable homotopy theory notions

Constructions

Lemmas

diagram chasing

Schanuel's lemma

Homology theories

Theorems

Contents

Definition

For N𝒜N \in \mathcal{A} an object, a projective cover is a morphism N˜N\tilde N \to N out of a projective object which is a superfluous epimorphism.

References

  • U. Shukla, On the projective cover of a module and related results, Pacific J. Math. Volume 12, Number 2 (1962), 709-717 (Euclid)

  • Wikipedia, Projective cover

Last revised on September 26, 2020 at 14:55:49. See the history of this page for a list of all contributions to it.