English

On orthogonal systems, two-sided bases and regular subfactors

Operator Algebras 2026-01-01 v3 Functional Analysis

Abstract

We prove that a regular subfator of type II1II_1 with finite Jones index always admits a two-sided Pimsner-Popa basis. This is preceeded by a pragmatic revisit of Popa's notion of orthogonal systems.

Cite

@article{arxiv.1904.05612,
  title  = {On orthogonal systems, two-sided bases and regular subfactors},
  author = {Keshab Chandra Bakshi and Ved Prakash Gupta},
  journal= {arXiv preprint arXiv:1904.05612},
  year   = {2026}
}

Comments

15 pages; Theorem 3.12 and few remarks added, feedback is welcome!

R2 v1 2026-06-23T08:36:33.629Z