Abstract
We show that if T is a narrow operator (for the definition see below) on X = X1 ⊕1 X2 or X = X1 ⊕∞ X2 then the restrictions to X 1 and X 2 are narrow and conversely. We also characterise by a version of the Daugavet property for positive operators on Banach lattices which unconditional sums of Banach spaces inherit the Daugavet property and we study the Daugavet property for ultraproducts.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 45-62 |
| Number of pages | 18 |
| Journal | Positivity |
| Volume | 9 |
| Issue number | 1 |
| DOIs | |
| State | Published - Mar 2005 |
| Externally published | Yes |
Bibliographical note
Funding Information:The work of V.K. was supported by a grant from the Alexander-von-Humboldt Stiftung.
Keywords
- Daugavet property
- Narrow operator
- Strong Daugavet operator
- Ultraproducts of Banach spaces