In this paper we discuss a multilinear generalization of the best rank-R approximation problem for matrices, namely, the approximation of a given higher-order tensor, in an optimal leastsquares sense, by a tensor that has prespecified column rank value, row rank value, etc. For matrices, the solution is conceptually obtained by truncation of the singular value decomposition (SVD); however, this...

The Fock space of m+p bosonic and n+q fermionic quantum oscillators forms a unitarizable module of the general linear superalgebra glm+p|n+q. Its tensor powers decompose into direct sums of infinite dimensional irreducible highest weight glm+p|n+q-modules. We obtain an explicit decomposition of any tensor power of this Fock space into irreducibles, and develop a character formula for the irredu...

‎The object of the present paper is to study spacetimes admitting‎ ‎quasi-conformal curvature tensor‎. ‎At first we prove that a quasi-conformally flat spacetime is Einstein‎ ‎and hence it is of constant curvature and the energy momentum tensor of such a spacetime satisfying‎ ‎Einstein's field equation with cosmological constant is covariant constant‎. ‎Next‎, ‎we prove that if the perfect flui...

This paper investigates the performance of a new multivariate method for Tensor-Based Morphometry (TBM). Statistics on Riemannian manifolds are developed that exploit the full information in deformation tensor fields. In TBM, multiple brain images are warped to a common neuroanatomical template via 3D nonlinear registration; the resulting deformation fields are analyzed statistically to identif...

Abstract: A dual mixed finite element method, for quasi–Newtonian fluid flow obeying the power law or the Carreau law, is constructed and analyzed in Farhloul–Zine [13]. This mixed formulation possesses good local (i.e., at element level) conservation properties (conservation of the momentum and the mass) as in the finite volume methods. In Farhloul–Zine [12], we developed an a posteriori error...

Inspired by the definition of symmetric decomposition, we introduce the concept of shape partition of a tensor and formulate a general tensor spectral problem that includes all the relevant spectral problems as special cases. We formulate irreducibility and symmetry properties of a nonnegative tensor T in terms of the associated shape partition. We recast the spectral problem for T as a fixed p...

Spatially homogeneous Bianchi type-II, VIII and IX anisotropic, as well as isotropic cosmological models can be obtained in a scalar tensor theory of gravitation proposed by Saez and Ballester (1986) when the source for energy momentum tensor is a bulk viscous fluid containing one-dimensional cosmic strings. All the models obtained and presented here are expanding, non-rotating and accelerating...

a method for deformation computation based on strain tensor elements, as an alternative to the usual way of application of gradient of displacement vector, is proposed. the method computes directly the strain tensor elements from the computed/observed changes in distances and angles between the stations of a geodetic network in two epochs of observations. displacement vector which is determined...