Flat extension and phantom homology

Phantom homology arises in tight closure theory due to small non-exactness when `kernel' is not equal to `image' but `kernel' is in the tight closure of the `image'. In this paper we study a typical flat extension, which we call *-flat extension, such that upon tensoring which pr...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Datum:2017
1. Verfasser: Bhattacharyya, Rajsekhar
Format: Artikel
Sprache:English
Veröffentlicht: Lugansk National Taras Shevchenko University 2017
Schlagworte:
Online Zugang:https://admjournal.luguniv.edu.ua/index.php/adm/article/view/41
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Назва журналу:Algebra and Discrete Mathematics

Institution

Algebra and Discrete Mathematics
Beschreibung
Zusammenfassung:Phantom homology arises in tight closure theory due to small non-exactness when `kernel' is not equal to `image' but `kernel' is in the tight closure of the `image'. In this paper we study a typical flat extension, which we call *-flat extension, such that upon tensoring which preserves phantom homology. Along with other properties, we observe that *-flat extension preserves ghost regular sequence, which is a typical `tight closure' generalization of regular sequence. We also show that in some situations, under *-flat extension, test ideal of the *-flat algebra is the expansion of the test ideal of the base ring.