S. Dilworth

activity

19982005

most citedSpectrum of a weakly hypercyclic operator meets the unit circle

2 citations · 2 across the 3 of their papers we have counts for

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9 papers · 1 filter

math.FA2005

Lattice structures and spreading models

S. J. Dilworth, E. Odell, B. Sari

We consider problems concerning the partial order structure of the set of spreading models of Banach spaces. We construct examples of spaces showing that the possible structure of…

math.FA2004

Embedding $ℓ_{\infty}$ into the space of all Operators on Certain Banach Spaces

G. Androulakis, K. Beanland, S. J. Dilworth +1

We give sufficient conditions on a Banach space $X$ which ensure that $ℓ_{\infty}$ embeds in $L (X)$ , the space of all operators on $X$ . We say that a basic sequence $(…

math.FA2002★ 2 cited

Spectrum of a weakly hypercyclic operator meets the unit circle

S. J. Dilworth, Vladimir G. Troitsky

It is shown that every component of the spectrum of a weakly hypercyclic operator meets the unit circle. The proof is based on the lemma that a sequence of vectors in a Banach spac…

math.FA2001

A general theory of almost convex functions

S. J. Dilworth, Ralph Howard, James W. Roberts

Let $Δ_{m}$ be the standard $m$ -dimensional simplex of non-negative $m + 1$ tuples that sum to unity and let $S$ be a nonempty subset of $Δ_{m}$ . A real valued function $h$ defined on a…

math.FA2000

Extremal Approximately Convex Functions and the Best Constants in a Theorem of Hyers and Ulam

S. J. Dilworth, Ralph Howard, James W. Roberts

Let $n \geq 1$ and $B \geq 2$ . A real-valued function $f$ defined on the $n$ -simplex $Δ_{n}$ is approximately convex with respect to $Δ_{B - 1}$ iff f(\sum_{i=1}^B t_ix_i) \le \sum_{i=1}^B t…

math.FA2000

A Conditional Quasi-greedy Basis of l_1

S. J. Dilworth, David Mitra

We show that the Lindenstrauss basic sequence in l_1 may be used to construct a conditional quasi-greedy basis of l_1, thus answering a question of Wojtaszczyk. We further show tha…