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P. Niroomand

Publications and source records attributed to P. Niroomand.

17 recordsLinked to original sources

The Bogomolov multiplier of Lie superalgebras

In this paper, we extend the notion of the Bogomolov multiplier and the commutativity preserving extension to Lie superalgebras. Moreover, we compute the Bogomolov multiplier of Heisenberg and real Lie superalgebras of dimension at most $4$.

math.RA

On the Schur multipliers of Lie superalgebras of maximal class

We categorize all non-abelian nilpotent Lie superalgebras of dimension $(m|n)$, where $1\leq s(L)\leq 10$, and $s(L)$ is a non-negative integer defined by Nayak. Furthermore, we classify the structure of all Lie superalgebras of dimension at most five such that $\dim{L^2}=\dim\mathcal{M}(L)$.

math.RA

On converse of the Schur's theorem for nilpotent Lie superalgebras

In this paper, we establish a converse to Schur's theorem for Lie superalgebras \( L \), focusing on cases where the minimal generator number pairs \((p \vert q)\) of \( L/Z(L) \) are considered, and where the superdimension \( \mathrm{sdim} L^{2} \) is finite. We introduce a new invariant \( st(L) \), which plays a key role in the classification of finite-dimensional nilpotent Lie superalgebras. Specifically, we classify the structure of all such Lie superalgebras \( L \) when \( st(L) \in \{(0,0), (1,0), (0,1), (2,0), (0,2), (1,1)\} \).

math.AC

$\tilde{B_0}$-invariant of groups

The Bogomolov multiplier of a group $G$ introduced by Bogomolov in $1988$. After that in $2012$, Moravec introduced an equivalent definition of the Bogomolov multiplier. In this paper we generalized the Bogomolov multiplier with respect to a variety of groups. Then we give some new results on this topic.

math.GR

Subgroup Theorems for the $\tilde{B_0}$-invariant of groups

U. Jezernik and P. Moravec have shown that if $G$ is a finite group with a subgroup $H$ of index $n$, then nth power of the Bogomolov multiplier of $G$, $\tilde{B_0}(G)^n$ is isomorphic to a subgroup of $\tilde{B_0}(H)$. In this paper we want to prove a similar result for the center by center by $w$ variety of groups, where $w$ is any outer commutator word.

math.GR

Characterizing nilpotent Lie algebras that satisfy on converse of the Schur's theorem

Let $ L $ be a finite dimensional nilpotent Lie algebra and $ d $ be the minimal number generators for $ L/Z(L). $ It is known that $ \dim L/Z(L)=d \dim L^{2}-t(L)$ for an integer $ t(L)\geq 0. $ In this paper, we classify all finite dimensional nilpotent Lie algebras $ L $ when $ t(L)\in \lbrace 0, 1, 2 \rbrace.$ We find also a construction, which shows that there exist Lie algebras of arbitrary $ t(L). $

math.RA

On characterizing nilpotent Lie algebra by their multiplier, $ s(L)=6, 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 $ \mathcal{M}(L) $ is the Schur multiplier of a Lie algebra $ L. $ The structures of nilpotent Lie algebras $ L $ when $ s(L)\in \lbrace 0,1,2,3,4,5\rbrace $ are determined. In this paper, we classify all non-abelian nilpotent Lie algebras $ L $ when $ s(L)=6,7. $

math.RA

Bogomolov multiplier and the Lazard correspondence

In this paper we extend the notion of CP covers for groups to the field of Lie algebras, and show that despite the case of groups, all CP covers of a Lie algebra are isomorphic. Finally we show that CP covers of groups and Lie rings which are in Lazard correspondence, are in Lazard correspondence too, and the Bogomolov multipliers are isomorphic.

math.GR

Nilpotent Lie algebras having the Schur multiplier of maximum dimension

Let $ L $ be an $ n $-dimensional nilpotent Lie algebra of nilpotency class $ c $ with the derived subalgebra of dimension $ m $. Recently, Rai proved that the dimension of Schur multiplier of $ L $ is bounded by $ \frac{1}{2}(n-m-1)(n+m)-\sum\limits_{i=2}^ {min\lbrace n-m,c\rbrace} n-m-i $. In this paper, we obtain the structure of all nilpotent Lie algebras that attain this bound.

math.AC

Classification of $p$-groups via their $2$-nilpotent multipliers

For a $p$-group of order $p^n$, it is known that the order of $2$-nilpotent multiplier is equal to $|\mathcal{M}^{(2)}(G)|=p^{\f12n(n-1)(n-2)+3-s_2(G)}$ for an integer $s_2(G)$. In this article, we characterize all of non abelian $p$-groups satisfying in $s_2(G)\in\{1,2,3\}.

math.GR

Decomposition of the nonabelian tensor product of Lie algebras via the diagonal ideal

We prove a theorem of splitting for the nonabelian tensor product $L \otimes N$ of a pair $(L,N)$ of Lie algebras $L$ and $N$ in terms of its diagonal ideal $L \square N$ and of the nonabelian exterior product $L \wedge N$. A similar circumstance was described two years ago by the second author in the special case $N=L$. The interest is due to the fact that the size of $L \square N$ influences strongly the structure of $L \otimes N$. Another question, often related to the structure of $L \otimes N$, deals with the behaviour of the operator $\square$ with respect to the formation of free products. We answer with another theorem of splitting even in this case, noting some connections with the homotopy theory.

math.RA

On the non-abelian tensor square of groups of order dividing $p^{5}$

In this paper we consider all groups of order dividing $p^5$. We obtain the explicit structure of the non-abelian tensor square, non-abelian exterior square, tensor center, exterior center, the third homotopy group of suspension of an Eilenberg-MacLain space $k(G,1) $ and $\triangledown(G)$ of such groups.

math.GR

$2$- capability and $2$- nilpotent multiplier of finite dimensional nilpotent Lie algebras

In the present context, we investigate to obtain some more results about $2$-nilpotent multiplier $\mathcal{M}^{(2)}(L)$ of a finite dimensional nilpotent Lie algebra $L$. For instance, we characterize the structure of $\mathcal{M}^{(2)}(H)$ when $H$ is a Heisenberg Lie algebra. Moreover, we give some inequalities on $ \mathrm{dim}~ \mathcal{M}^{(2)}(L)$ to reduce a well known upper bound on $2$-nilpotent multiplier as much as possible. Finally, we show that $H(m)$ is 2-capable if and only if m=1.

math.RA