Lobachevskii Journal of Mathematics Volume 35 Issue 1

Journal Article

Composite convolution operators on weighted sequence spaces

Singh, Virender; Komal, B.

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010089

This paper deals with the composite convolution operators on the weighted sequence spaces. Bounded, Hermitian composite convolution operators are characterized. Compact and Hilbert-Schmidt composite convolution operators are obtained. Adjoint of the composite convolution operator is computed....

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Journal Article

On two properties of the augmentation ideal I(G)

Ghanem, Manal; Al-Ezeh, Hasan

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010041

All rings considered are commutative with unity and all groups considered are abelian. We give a characterization of a pure augmentation ideal, I(G), of a group ring, R(G). We study the relationship between the p-injectivity of R(G) and the p-injectivity of its ideal I(G). Keywords and phrases:...

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Journal Article

A study on Legendre curves in 3-dimensional trans-Sasakian manifolds

Sarkar, A.; Hui, S.; Sen, Matilal

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010077

The object of the present paper is to show that Theorem 3 of the paper [22] on 3-dimensional quasi-Sasakianmanifolds can be extended to 3-dimensional trans-Sasakian manifolds. We also find the curvature and torsion of Legendre curves in 3-dimensional trans-Sasakian manifolds with respect to...

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Journal Article

Scattered linear orderings with no computable presentation

Frolov, A.

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S199508021401003X

In this paper we construct a low2 scattered linear orderings with no computable presentation. This is a negative answer for the question of A. Kach and A. Montalbán.

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Journal Article

Nonexistence of ϕ-recurrent generalized Sasakian-space-forms in a special case

Peyghan, E.; Tayebi, A.

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010065

We show that there is no ϕ-recurrent generalized Sasakian-space-forms, when f 1 — f 3 is a non-zero constant.

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Journal Article

Using genetic algorithms to generate D s -optimal response surface designs

Sirisom, P.; Chaimongkol, S.; Borkowski, J.

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010090

This research introduces a new approach to the generation of D s -optimal designs for subsets of parameters of the second-order response surface model for 2, 3, and 4-dimensional hypercube design spaces while simultaneously satisfying a specified minimum value for the D-efficiency for the full...

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Journal Article

Deformation of curvature tensors under conformal Ricci flow

Basu, Nirabhra; Bhattacharyya, Arindam

2014 Lobachevskii Journal of Mathematics

doi:10.1134/S1995080214010028