‎Let $G$ be a finite $p$-group of order $p^n$ and‎ ‎$|{mathcal M}(G)|=p^{frac{1}{2}n(n-1)-t(G)}$‎, ‎where ${mathcal M}(G)$‎ ‎is the Schur multiplier of $G$ and $t(G)$ is a nonnegative integer‎. ‎The classification of such groups $G$ is already known for $t(G)leq‎ ‎6$‎. ‎This paper extends the classification to $t(G)=7$.

Let L be an n-dimensional non-abelian nilpotent Lie algebra and $$ s(L)=\frac{1}{2}(n-1)(n-2)+1-\dim {\mathcal {M}}(L) where is the Schur multiplier of a L. The structures algebras when s(L)\in \lbrace 0,1,2,3,4,5\rbrace are determined. In this paper, we classify all s(L)=6,7.

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A method for the analytical enumeration of circulant graphs with p2 vertices, p a prime, is proposed and described in detail. It is based on the use of S-rings and P olya's enumeration technique. Two di erent approaches, \structural" and \multiplier", are developed and compared. As a result we get counting formulae and generating functions (by valency) for non-isomorphic p2-vertex directed and ...

let $g$ be a $p$-group of nilpotency class $k$ with finite exponent $exp(g)$ and let $m=lfloorlog_pk floor$. we show that $exp(m^{(c)}(g))$ divides $exp(g)p^{m(k-1)}$, for all $cgeq1$, where $m^{(c)}(g)$ denotes the c-nilpotent multiplier of $g$. this implies that $exp( m(g))$ divides $exp(g)$, for all finite $p$-groups of class at most $p-1$. moreover, we show that our result is an improvement...

An improvement of a bound of Yankosky (2003) is presented in this paper, thanks to a restriction which has been recently obtained by the authors on the Schur multiplier M(L) of a finite dimensional nilpotent Lie algebra L. It is also described the structure of all nilpotent Lie algebras such that the bound is attained. An important role is played by the presence of a derived subalgebra of maxim...

We prove an integral version of the Schur–Weyl duality between the specialized Birman–Murakami–Wenzl algebra Bn(−q , q) and the quantum algebra associated to the symplectic Lie algebra sp2m. In particular, we deduce that this Schur–Weyl duality holds over arbitrary (commutative) ground rings, which answers a question of Lehrer and Zhang ([37]) in the symplectic case. As a byproduct, we show tha...

We compute the norm of the restriction of a Schur multiplier, arising from a multiplication operator, to a coordinate subspace. This result is used to generalize Wielandt’s minimax inequality. Furthermore, we compute various s-numbers of an elementary Schur multiplier and determine criteria for membership of such multipliers in certain operator ideals.