13. Norm attaining operators of finite rank
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Vladimir Kadets
Abstract
We provide sufficient conditions on a Banach space X in order that there exist norm attaining operators of rank at least two from X into any Banach space of dimension at least two. For example, a rather weak such condition is the existence of a nontrivial cone consisting of norm attaining functionals on X. We go on to discuss density of norm attaining operators of finite rank among all operators of finite rank, which holds for instance when there is a dense linear subspace consisting of norm attaining functionals on X. In particular, we consider the case of Hilbert space valued operators where we obtain a complete characterization of these properties. In the final section, we offer a candidate for a counterexample to the complex Bishop-Phelps theorem on c0, the first such counterexample on a certain complex Banach space being due to V. Lomonosov.
Abstract
We provide sufficient conditions on a Banach space X in order that there exist norm attaining operators of rank at least two from X into any Banach space of dimension at least two. For example, a rather weak such condition is the existence of a nontrivial cone consisting of norm attaining functionals on X. We go on to discuss density of norm attaining operators of finite rank among all operators of finite rank, which holds for instance when there is a dense linear subspace consisting of norm attaining functionals on X. In particular, we consider the case of Hilbert space valued operators where we obtain a complete characterization of these properties. In the final section, we offer a candidate for a counterexample to the complex Bishop-Phelps theorem on c0, the first such counterexample on a certain complex Banach space being due to V. Lomonosov.
Kapitel in diesem Buch
- Frontmatter I
- Editors’ Introduction V
- Per Enflo’s personal thoughts about Victor Lomonosov VII
- Contents XI
- 1. Bishop–Phelps–Bollobás property for positive operators between classical Banach spaces 1
- 2. Isometric embeddings of finite metric trees into (ℝn, d1) and (ℝn, d∞) 15
- 3. Iterates of the spherical Aluthge transform of 2-variable weighted shifts 25
- 4. The freewheeling twisting of Hilbert spaces 43
- 5. A survey of ball-covering property of Banach spaces 67
- 6. A note on the quantitative local version of the log-Brunn–Minkowski inequality 85
- 7. Spectra of “fattened” open book structures 99
- 8. On some local Bishop–Phelps–Bollobás properties 109
- 9. Bounded point derivations of fractional orders 123
- 10. Invariant subspaces: some minimal proofs 131
- 11. On the Hypercyclicity Criterion for operators of Read’s type 139
- 12. Three-space problem for strictly convex renormings 149
- 13. Norm attaining operators of finite rank 157
- 14. Isometric copies of ℓn∞ and ℓn1 in transportation cost spaces on finite metric spaces 189
- 15. From Lomonosov lemma to radical approach in joint spectral radius theory 205
- 16. Pontryagin–Krein theorem: Lomonosov’s proof and related results 231
- 17. Poincaré type and spectral gap inequalities with fractional Laplacians on Hamming cube 251
- 18. Spectra of generalized Poisson integral operators on Lp(ℝ+) 281
- 19. Order extreme points and solid convex hulls 297
- 20. Universal block tridiagonalization in ℬ(ℋ) and beyond 317
- 21. Rademacher-type independence in Boolean algebras 327
- Index 349
Kapitel in diesem Buch
- Frontmatter I
- Editors’ Introduction V
- Per Enflo’s personal thoughts about Victor Lomonosov VII
- Contents XI
- 1. Bishop–Phelps–Bollobás property for positive operators between classical Banach spaces 1
- 2. Isometric embeddings of finite metric trees into (ℝn, d1) and (ℝn, d∞) 15
- 3. Iterates of the spherical Aluthge transform of 2-variable weighted shifts 25
- 4. The freewheeling twisting of Hilbert spaces 43
- 5. A survey of ball-covering property of Banach spaces 67
- 6. A note on the quantitative local version of the log-Brunn–Minkowski inequality 85
- 7. Spectra of “fattened” open book structures 99
- 8. On some local Bishop–Phelps–Bollobás properties 109
- 9. Bounded point derivations of fractional orders 123
- 10. Invariant subspaces: some minimal proofs 131
- 11. On the Hypercyclicity Criterion for operators of Read’s type 139
- 12. Three-space problem for strictly convex renormings 149
- 13. Norm attaining operators of finite rank 157
- 14. Isometric copies of ℓn∞ and ℓn1 in transportation cost spaces on finite metric spaces 189
- 15. From Lomonosov lemma to radical approach in joint spectral radius theory 205
- 16. Pontryagin–Krein theorem: Lomonosov’s proof and related results 231
- 17. Poincaré type and spectral gap inequalities with fractional Laplacians on Hamming cube 251
- 18. Spectra of generalized Poisson integral operators on Lp(ℝ+) 281
- 19. Order extreme points and solid convex hulls 297
- 20. Universal block tridiagonalization in ℬ(ℋ) and beyond 317
- 21. Rademacher-type independence in Boolean algebras 327
- Index 349
