English

Notes on universal C*-algebras

Operator Algebras 2026-07-17 v1 Rings and Algebras

Abstract

In these notes, we explain in details the construction of the universal C*-algebra as done by Blackadar, starting with the construction of the free *-algebra. At the end, we explain the extension done by Boava and the author to include relations described using the strong operator topology. As an example, we show that a graph C*-algebra can be defined using infinite sums.

Cite

@article{arxiv.2607.15539,
  title  = {Notes on universal C*-algebras},
  author = {Gilles G. de Castro},
  journal= {arXiv preprint arXiv:2607.15539},
  year   = {2026}
}

Comments

Notes for three lectures given at IMPAN in 2023 part of the Banach Center Simons Semester Operator Algebras That One Can See