we study the theory of best approximation in tensor product and the direct sum of some lattice normed spacesx_{i}. we introduce quasi tensor product space anddiscuss about the relation between tensor product space and thisnew space which we denote it by x boxtimesy. we investigate best approximation in direct sum of lattice normed spaces by elements which are not necessarily downwardor upward a...

This article addresses the problem of cardinality estimation in inner product spaces. Given a set high-dimensional vectors, query, and threshold, this estimates number vectors such that their products with query are not less than threshold. is an important for recent machine-learning applications maintain objects, as users items, by using matrices. The requirements solutions high efficiency acc...

A formal treatment of Killing 1-form and 2-Killing on Riemannian Poisson manifold, warped product space are presented. In this way, we obtain Bochner type results compact for 1-form. Finally, give the characterization a (R2, 1,?).