The authors discuss mainly that the Riemannian manifold Mn admitting a unit preserving circle field ? in present paper. A sufficient and necessary condition is given an Einstein by imposing some conditions on W2 curvature tensor. Further, this paper obtains algebra representation of tensors W2-recurrent R???? = 1/d2 [d?d?R?? d?d?R?? + d?d?R??].

We study electrical modulation of transport properties silicene nanoconstrictions with different geometrical structures. investigate the effects position and width central scattering region on conductance increasing Fermi energy. It is found that significantly depends nanoconstriction. Interestingly, symmetrical structure constriction can induce a resonance effect increase systemʼs conductance....

Based on the point of view of geometrical representation of an intuitionistic fuzzy set, we take into account all three parameters describing intuitionistic fuzzy set, propose a kind of new method to calculate correlation and correlation coefficient of intuitionistic fuzzy sets which is similar to the cosine of the intersectional angle in finite sets and probability space, respectively. Further...

In this paper, the notion of rank-k numerical range of rectangular complex matrix polynomials are introduced. Some algebraic and geometrical properties are investigated. Moreover, for ϵ > 0; the notion of Birkhoff-James approximate orthogonality sets for ϵ-higher rank numerical ranges of rectangular matrix polynomials is also introduced and studied. The proposed denitions yield a natural genera...