On the (non-)surjectivity of compact operators
Sign Up to like & getrecommendations! Published in 2019 at "Archiv der Mathematik"
DOI: 10.1007/s00013-019-01321-w
Abstract: First, a general method to construct compact surjective operators between infinite-dimensional normed spaces is given. Thereafter, a sufficient condition is obtained to assure the non-surjectivity of compact operators. read more here.
Keywords: compact operators; surjectivity compact; non surjectivity;
On the Compact Operators Case of the Bishop–Phelps–Bollobás Property for Numerical Radius
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DOI: 10.1007/s00025-021-01430-5
Abstract: We study the Bishop–Phelps–Bollobas property for numerical radius restricted to the case of compact operators (BPBp-nu for compact operators in short). We show that $$C_0(L)$$ spaces have the BPBp-nu for compact operators for every Hausdorff… read more here.
Keywords: bpbp compact; property; compact operators; property numerical ... See more keywords
On sums of narrow and compact operators
Sign Up to like & getrecommendations! Published in 2019 at "Positivity"
DOI: 10.1007/s11117-019-00666-4
Abstract: We prove, in particular, that if E is a Dedekind complete atomless Riesz space and X is a Banach space then the sum of a narrow and a C-compact laterally continuous orthogonally additive operators from… read more here.
Keywords: narrow compact; compact operators; sums narrow;
Low rank compact operators and Tingley's problem
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DOI: 10.1016/j.aim.2018.08.018
Abstract: Let $E$ and $B$ be arbitrary weakly compact JB$^*$-triples whose unit spheres are denoted by $S(E)$ and $S(B)$, respectively. We prove that every surjective isometry $f: S(E) \to S(B)$ admits an extension to a surjective… read more here.
Keywords: isometry; low rank; compact operators; tingley problem ... See more keywords
The injective and surjective hulls of the ideal of (p,q)-compact operators and their approximation properties
Sign Up to like & getrecommendations! Published in 2019 at "Journal of Mathematical Analysis and Applications"
DOI: 10.1016/j.jmaa.2018.12.035
Abstract: Abstract Let 1 ≤ p , q ≤ ∞ with 1 / p + 1 / q ≥ 1 . We establish the isometric representations of the injective hull K i n j p ,… read more here.
Keywords: injective surjective; banach space; ideal compact; compact operators ... See more keywords
Matrix transformations and compact operators on Catalan sequence spaces
Sign Up to like & getrecommendations! Published in 2021 at "Journal of Mathematical Analysis and Applications"
DOI: 10.1016/j.jmaa.2021.124925
Abstract: Abstract This paper is devoted to the study of domain of a recently defined conservative matrix in the spaces of p-absolutely summable sequences and bounded sequences. The aforementioned matrix is obtained by using the fascinating… read more here.
Keywords: matrix transformations; sequence spaces; catalan sequence; transformations compact ... See more keywords
EQUIVALENCE OF SEMI-NORMS RELATED TO SUPER WEAKLY COMPACT OPERATORS
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DOI: 10.1017/s0004972721000435
Abstract: Abstract We study super weakly compact operators through a quantitative method. We introduce a semi-norm $\sigma (T)$ of an operator $T:X\to Y$ , where X, Y are Banach spaces, the so-called measure of super weak… read more here.
Keywords: equivalence semi; compact operators; semi norms; super weakly ... See more keywords
The ideal of unconditionally $p$-compact operators
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DOI: 10.1216/rmj-2017-47-7-2277
Abstract: We investigate the ideal Kup, 1 ≤ p ≤ ∞, of unconditionally p-compact operators. We obtain the isometric identities Kup = Kup ◦ Kup, Kmax up = Lsur p∗ , K min up = ⊗̂/wp∗… read more here.
Keywords: unconditionally compact; ideal unconditionally; kup; compact operators ... See more keywords
A study on q-analogue of generalized Motzkin sequence spaces, their matrix transformations and compact operators
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DOI: 10.1371/journal.pone.0329210
Abstract: In this article, we have constructed generalized q-difference Motzkin sequence spaces M0q(Δqm), Mcq(Δqm), Mpq(Δqm) and M∞q(Δqm) by composing q-Motzkin matrix with generalized q-difference matrix in the spaces c0,c,lp,l∞, respectively and explore their topological properties. We… read more here.
Keywords: compact operators; spaces m0q; study analogue; sequence spaces ... See more keywords
Characterizations of compact operators on ℓp−type fractional sets of sequences
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DOI: 10.1515/dema-2019-0015
Abstract: Abstract Among the sets of sequences studied, difference sets of sequences are probably the most common type of sets. This paper considers some ℓp−type fractional difference sets via the gamma function. Although, we characterize compactness… read more here.
Keywords: compact operators; fractional sets; characterizations compact; sets sequences ... See more keywords
A characterization of essential pseudospectra involving polynomially compact operators
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DOI: 10.2298/fil2433675e
Abstract: In this article, we study the essential pseudospectra with the class of polynomially compact operators, which is a generalization of the class of compact operators. We present some new results in essential pseudospectra for closed… read more here.
Keywords: compact operators; polynomially compact; pseudospectra involving; essential pseudospectra ... See more keywords