We characterize the initial terms under a diagonal term order of the supersymmetric Schur/Weyl module S(V V ) associated to a row-convex shape D. We show the biwords corresponding to the initial terms of S are closed under dual-Knuth equivalence and that the recording tableaux for these words are decomposable in the sense of [10]. We consider the natural action of bases of S in which the elemen...

We study the large scale geometry of the upper triangular subgroup of PSL2(Z[ 1 n ]), which arises naturally in a geometric context. We prove a quasi-isometry classification theorem and show that these groups are quasi-isometrically rigid with infinite dimensional quasi-isometry group. We generalize our results to a larger class of groups which are metabelian and are higher dimensional analogue...

Article history: Received 12 September 2015 Accepted 21 December 2015 Available online xxxx Submitted by R. Brualdi MSC: primary 05E15 secondary 15A21

In this paper, we investigate the recently defined notion of inverse along an element in the context of matrices over a ring. Precisely, we study the inverse of a matrix along a lower triangular matrix, under some conditions.

For the all-ones lower triangular matrices, the upper and lower bounds on rigidity are known to match [13]. In this short note, we apply these techniques to the allones extended lower triangular matrices, to obtain upper and lower bounds with a small gap between the two; we show that the rigidity is θ( 2 r ).

In this paper, a new algorithm of approximating rational triangular B-B surfaces using polynomial triangular B-B surfaces is presented. This algorithm has a simple expression and insured convergence. The core idea of the algorithm is to yield a polynomial triangular B-B surface, which has the same degree and new control vertices of the degree-elevated rational triangular B-B surface, to approxi...

Ducted propeller is a method on the modification which added duct/nozzle propeller. application aimed to increase thrust, efficiency, and decrease noise vibration. In this research, numerical simulation was conducted using ANSYS Fluent 2020 R2 with k-epsilon solver model. The aim of research analyze effect duct geometry Ld/D (duct length/duct diameter) ratio. done two variations at three differ...