The theory of cat1-2-groups among higher categorical models


Temel S.

AIMS Mathematics, cilt.11, sa.3, ss.6141-6161, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 11 Sayı: 3
  • Basım Tarihi: 2026
  • Doi Numarası: 10.3934/math.2026254
  • Dergi Adı: AIMS Mathematics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Directory of Open Access Journals
  • Sayfa Sayıları: ss.6141-6161
  • Anahtar Kelimeler: 2-group, cat1-group, crossed module, group object, internal category
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

In this paper, we introduce the notions of cat1-2-groups, which are defined as group objects in the category of cat1-categories (or cat1-groupoids). We investigated their structure and established fundamental categorical equivalences that connect them with classical algebraic constructs. Central to our work was the introduction of cat1-crossed modules over groups, which were demonstrated to be an equivalent and more manageable algebraic model for cat1-2-groups. We established categorical equivalences between cat1-2-groups, crossed modules over 2-groups, and cat1-crossed modules. We also obtained cat1-2-groups as internal cat1-categories in the category of groups. Furthermore, we explored simplicial 2-groups whose Moore complex was of length one, proving their equivalence with cat1-2-groups. Our findings were extended to define catn-2-groups, generalizing the theory to higher dimensions. These results offer algebraic tractability and deepen the structural understanding within higher-dimensional categorical algebra.