It has been an open problem to derive a necessary and sufficient condition for a linear tensor product problem S = {Sd} in the average case setting to be weakly tractable but not polynomially tractable. As a result of the tensor product structure, the eigenvalues of the covariance operator of the induced measure in the one dimensional problem characterize the complexity of approximating Sd, d ≥...

H. Friedman obtained remarkable results about the longest finite sequence x over a finite alphabet such that for all i 6= j the word x[i..2i] is not a subsequence of x[j..2j]. In this note we consider what happens when “subsequence” is replaced by “subword”; we call such a sequence a “weakly selfavoiding word”. We prove that over an alphabet of size 1 or 2, there is an upper bound on the length...

In this paper, employing the common property ($E.A$), we prove a common fixed theorem for weakly compatible mappings via an implicit relation in Intuitionistic fuzzy metric space. Our results generalize the results of S. Kumar [S. Kumar, {it Common fixed point theorems in Intuitionistic fuzzy metric spaces using property (E.A)}, J. Indian Math. Soc., 76 (1-4) (2009), 94--103] and C. Alaca et al...

We define two classes of rings calling them weakly clean rings and weakly exchange rings both equipped with the strong property. Although the classes of weakly clean rings and weakly exchange rings are different, their two proper subclasses above do coincide. This extends results due to W. Chen (Commun. Algebra, 2006) and Chin-Qua (Acta Math. Hungar., 2011). We also completely characterize stro...

We show that under minor technical assumptions any weakly nonlocal Hamiltonian structures compatible with a given nondegenerate weakly nonlocal symplectic operator J can be written as the Lie derivatives of J along a suitably chosen nonlocal vector field. Moreover, we present a new description for local Hamiltonian structures of arbitrary order compatible with a given nondegenerate local Hamilt...

We prove common fixed point theorems in symmetric spaces for two pairs of hybrid mappings using the concept of T−weakly and S−weakly commuting mappings satisfying generalized contractive conditions which generalize theorems of Aamri and El Moutawakil [J. Math. Anal. Appl., 270 (2002), 181–188.], Aamri and El Moutawakil [Appl. Math. E-notes., 3 (2003), 156–162.] and Aliouche [J. Math. Anal. Appl...

Let C1 and C2 be codes with code distance d. Codes C1 and C2 are called weakly isometric, if there exists a mapping J : C1 → C2, such that for any x, y from C1 the equality d(x, y) = d holds if and only if d(J(x), J(y)) = d. Obviously two codes are weakly isometric if and only if the minimal distance graphs of these codes are isomorphic. In this paper we prove that Preparata code of length n ≥ ...

The Banach space E has the weakly compact approximation property (W.A.P. for short) if there is a constant C < ∞ so that for any weakly compact set D ⊂ E and ε > 0 there is a weakly compact operator V : E → E satisfying supx∈D ‖x − V x‖ < ε and ‖V ‖ ≤ C. We give several examples of Banach spaces both with and without this approximation property. Our main results demonstrate that the James-type ...

A uniformly recurrent pseudoword is an element of a free profinite semigroup in which every finite factor appears in every sufficiently long finite factor. An alternative characterization is as a pseudoword which is a factor of all its infinite factors, that is one which lies in a J -class with only finite words strictly J -above it. Such a J -class is regular and therefore it has an associated...