Contents:

SUMMARY


INTRODUCTION


I - TORSION THEORIES IN ABELIAN CATEGORIES


1.Torsion theories: genesis and evolution.
2. Hereditary torsion theories.
3. Torsion theories in the category of abelian groups.


II - TORSION THEORIES IN CATEGORIES WITH INITIAL AND TERMINAL OBJECTS

1. Reflective subcategories and prefactorization systems.
2. Categories of fractions.
3. Finitely well-complete categories.
4. Reflective subcategories and coreflective subcategories associated with a factorization system.
5. Torsion theories.
6. Torsion theories in categories without zero object.
7. Torsion theories in categories with zero object.
8. Connectednesses and reflections.


III - LOCALIZATIONS AND TORSION THEORIES

1. Some types of reflections.
2. Localizations and hereditary torsion theories.
3. Some classical cases.


REFERENCES