top
Given a long exact sequence of abelian groupsL: ... → Li-1 →ξi-1 Li →ξi Li+1 → ...a short exact sequence of complexes of free abelian groups is constructed whose cohomology long exact sequence is precisely L. In this sense, L is realized. Two techniques which are introduced to reduce or replace lengthy diagram chasing arguments may be of interest to some readers. One is an arithmetic of bicartesian squares; the other is the use of the fact that categories of morphisms of abelian categories are themselves abelian.
Pressman, Irwin S.. "Realization of long exact sequences of abelian groups.." Publicacions Matemàtiques 34.1 (1990): 67-76. <http://eudml.org/doc/41114>.
@article{Pressman1990, abstract = {Given a long exact sequence of abelian groupsL: ... → Li-1 →ξi-1 Li →ξi Li+1 → ...a short exact sequence of complexes of free abelian groups is constructed whose cohomology long exact sequence is precisely L. In this sense, L is realized. Two techniques which are introduced to reduce or replace lengthy diagram chasing arguments may be of interest to some readers. One is an arithmetic of bicartesian squares; the other is the use of the fact that categories of morphisms of abelian categories are themselves abelian.}, author = {Pressman, Irwin S.}, journal = {Publicacions Matemàtiques}, keywords = {Teoría de grupos; Grupos; Grupos abelianos; category of abelian groups; cohomology of complexes; cohomology sequence of a short exact sequence of complexes of abelian groups; long exact sequence of abelian groups; bicartesian squares}, language = {eng}, number = {1}, pages = {67-76}, title = {Realization of long exact sequences of abelian groups.}, url = {http://eudml.org/doc/41114}, volume = {34}, year = {1990}, }
TY - JOUR AU - Pressman, Irwin S. TI - Realization of long exact sequences of abelian groups. JO - Publicacions Matemàtiques PY - 1990 VL - 34 IS - 1 SP - 67 EP - 76 AB - Given a long exact sequence of abelian groupsL: ... → Li-1 →ξi-1 Li →ξi Li+1 → ...a short exact sequence of complexes of free abelian groups is constructed whose cohomology long exact sequence is precisely L. In this sense, L is realized. Two techniques which are introduced to reduce or replace lengthy diagram chasing arguments may be of interest to some readers. One is an arithmetic of bicartesian squares; the other is the use of the fact that categories of morphisms of abelian categories are themselves abelian. LA - eng KW - Teoría de grupos; Grupos; Grupos abelianos; category of abelian groups; cohomology of complexes; cohomology sequence of a short exact sequence of complexes of abelian groups; long exact sequence of abelian groups; bicartesian squares UR - http://eudml.org/doc/41114 ER -