Abstract
Let R be an associative ring with unit 1, and let a,b,c∈R satisfy (ac)2a=abaca=acaba=a(ba)2. We prove that if α=1-ba is generalized Drazin invertible, then 1-ac is generalized Drazin invertible. This extends the results given by Chen and Abdolyousefi (Comm. Algebra, 49 (2021) 3263-3272) from Banach algebras to rings. Moreover, Jacobson’s lemma for generalized Fredholm elements relative to an ideal and Fredholm elements relative to a trace ideal is investigated in rings and in semisimple Banach algebras, respectively. Applying the above results, norm closure of hypercyclic operators is considered.
| Original language | English |
|---|---|
| Pages (from-to) | 2949-2964 |
| Number of pages | 16 |
| Journal | Ricerche di Matematica |
| Volume | 74 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Nov 2025 |
| Externally published | Yes |
Keywords
- Drazin inverses
- Fredholm elements
- Generalized Fredholm elements
- Hypercyclic operator
- Jacobson’s lemma