2023/06/01 by Chenlin Hu, Hu, Chaolong, You Qing Ji +1
Mathematics · #Holomorphic and Operator Theory
paper · pdf · doi:10.48550/arxiv.2306.00387
For a quasinilpotent operator T on a Banach space X, Douglas and Yang defined kx=\limsupz→ 0\fracln‖(z-T)-1x‖ln‖(z-T)-1‖ for each nonzero vector x∈ X, and call Λ(T)=\kx: x≠ 0\ the power set of T. They proved that the power set have a close link with T's lattice of hyperinvariant subspaces. This paper computes the power set of quasinilpotent weighted shifts on lp for 1≤ p< ∞. We obtain the following results: (1) If T is an injective quasinilpotent forward unilateral weighted shift on lp(ℕ), then Λ(T)=\1\ when ke0=1, where \en\n=0∞ be the canonical basis for lp(ℕ); (2) There is a class of backward unilateral weighted shifts on lp(ℕ) whose power set is [0,1]; (3) There exists a bilateral weighted shift on lp(ℤ) with power set [(1)/(2),1].