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Wende Liu

Publications and source records attributed to Wende Liu.

32 records · Page 2Linked to original sources

Maximal Subalgebras for Lie Superalgebras of Cartan Type

The maximal graded subalgebras for four families of Lie superalgebras of Cartan type over a field of prime characteristic are studied. All maximal reducible graded subalgebras are described completely and their isomorphism classes, dimension formulas are found. The classification of maximal irreducible graded subalgebras is reduced to the classification of the maximal irreducible subalgebras for the classical Lie superalgebras $\frak{gl}(m,n)$, $\frak{sl}(m,n)$ and $\frak{osp}(m,n)$.

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Generators of simple modular Lie superalgebras

Let $X$ be one of the finite-dimensional simple graded Lie superalgebras of Cartan type $W, S, H, K, HO, KO, SHO$ or $SKO$ over an algebraically closed field of characteristic $p>3$. In this paper we prove that $X$ can be generated by one element except the ones of type $W,$ $HO$, $KO$ or $SKO$ in certain exceptional cases, in which $X$ can be generated by two elements. As a subsidiary result, we also prove that certain classical Lie superalgebras or their relatives can be generated by one or two elements.

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Superderivations for Modular Graded Lie Superalgebras of Cartan-type

Superderivations for the eight families of finite or infinite dimensional graded Lie superalgebras of Cartan-type over a field of characteristic $p>3$ are completely determined by a uniform approach: The infinite dimensional case is reduced to the finite dimensional case and the latter is further reduced to the restrictedness case, which proves to be far more manageable. In particular, the outer superderivation algebras of those Lie superalgebras are completely determined.

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Automorphism groups of the finite dimensional special odd Hamiltonian superalgebras in prime characteristic

This paper is devoted to a study of the automorphism groups of three series of finite dimensional special odd Hamiltonian superalgebras $\mathfrak{g}$ over a field of prime characteristic. Our aim is to characterize the connections between the automorphism groups of $\mathfrak{g}$ and the automorphism groups of the corresponding underlying superalgebras. Precisely speaking, we embed the former into the later. Moreover, we determine the images of the normal series of the automorphism groups and homogeneous automorphism groups of $\mathfrak{g.}$

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Derivations of the finite-dimensional special odd Hamiltonian superalgebras

The aim is to determine the derivations of the three series of finite-dimensional Z-graded Lie superalgebras of Cartan-type over a field of characteristic p > 3, called the special odd Hamiltonian superalgebras. To that end we first determine the derivations of negative Z-degree for the restricted and simple special odd Hamiltonian superalgebras by means of weight space decompositions. Then the results are used to determine the derivations of negative Z-degree for the nonrestricted and non-simple special odd Hamiltonian superalgebras. Finally the derivation algebras and the outer derivation algebras of those Lie superalgebras are completely determined.

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Filtration, automorphisms and classification of the infinite dimensional odd Contact superalgebras superalgebras

The principal filtration of the infinite-dimensional odd Contact Lie superalgebra over a field of characteristic $p>2$ is proved to be invariant under the automorphism group by investigating ad-nilpotent elements and determining certain invariants such as subalgebras generated by some ad-nilpotent elements. Then, it is proved that two automorphisms coincide if and only if they coincide on the -1 component with respect to the principal grading. Finally, all the odd Contact superalgebras are classified up to isomorphisms.

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Finite dimensional special odd contact superalgebras over a field of prime characteristic

This paper considers a family of finite dimensional simple Lie superalgebras of Cartan type over a field of characteristic $p>3$, the so-called special odd contact superalgebras. First, the spanning sets are determined for the Lie superalgebras and their relatives. Second, the spanning sets are used to characterize the simplicity and to compute the dimension formulas. Third, we determine the superderivation algebras and the first cohomology groups. Finally, the dimension formulas and the first cohomology groups are used to make a comparison between the special odd contact superalgebras and the other simple Lie superalgebras of Cartan type.

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Associative forms and second cohomologies of Lie superalgebras $HO$ and $KO$

We consider two families of finite-dimensional simple Lie superalgebras of Cartan type, denoted by HO and KO, over an algebraically closed field of characteristic p>3. Using the weight space decompositions and the principal gradings we first show that neither HO nor KO possesses a nondegenerate associative form. Then, by means of computing the superderivations from the Lie superalgebras in consideration into their dual modules, the second cohomology groups with coefficients in the trivial modules are proved to be vanishing.

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Derivations for the even part of the Hamiltonian superalgebra in positive characteristic

In this paper we consider the derivations for even part of the finite-dimensional Hamiltonian superalgebra $H$ over a field of prime characteristic. We first introduce an ideal $\frak{N}$ of $H_{\bar{0}}$ and show that the derivation space from $H_{\bar{0}}$ into $W_{\bar{0}}$ can be obtained by the derivation space from $\frak{N}$ into $W_{\bar{0}},$ the even part of the generalized Witt superalgebra $W$. For further application we also give the generating set of the ideal $\frak{N}$. Then we describe three series of exceptional derivations from $ {H}_{\bar{0}}$ into $W_{\bar{0}}.$ Finally, we determine all the derivations vanishing on the non-positive $\mathbb{Z}$-graded part of $ H_{\bar{0}}$, the odd $\mathbb{Z}$-homogeneous derivations, and negative $\mathbb{Z}$-homogeneous derivations from ${H}_{\bar{0}}$ into $W_{\bar{0}}.$

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Derivations from the even parts into the odd parts for Lie superalgebras W and S

Let $\mathcal{W}$ and $\mathcal{S}$ denote the even parts of the general Witt superalgebra $W$ and the special superalgebra $S$ over a field of characteristic $ p>3,$ respectively. In this note, using the method of reduction on $\mathbb{Z}$-gradations, we determine the derivation space $\mathrm{Der}(\mathcal{W}, W_{\bar{1}})$ from $\mathcal{W}$ into $W_{\bar{1}} $ and the derivation space $\mathrm{Der}(\mathcal{S}, W_{\bar{1}})$ from $\mathcal{S}$ into $W_{\bar{1}}. $ In particular, the derivation space $\mathrm{Der}(\mathcal{S}, S_{\bar{1}})$ is determined.

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Derivations for the even parts of modular Lie superalgebras $W$ and $S$ of Cartan type

Let $\mathbb{F}$ be the underlying base field of characteristic $p>3 $ and denote by $\mathcal{W}$ and $\mathcal{S}$ the even parts of the finite-dimensional generalized Witt Lie superalgebra $W$ and the special Lie superalgebra $S,$ respectively. We first give the generator sets of the Lie algebras $\mathcal{W}$ and $\mathcal{S}.$ Using certain properties of the canonical tori of $\mathcal{W}$ and $\mathcal{S},$ we then determine the derivation algebra of $\mathcal{W}$ and the derivation space of $\mathcal{S} $ to $\mathcal{W},$ where $\mathcal{W}$ is viewed as $\mathcal{S} $-module by means of the adjoint representation. As a result, we describe explicitly the derivation algebra of $\mathcal{S}.$ Furthermore, we prove that the outer derivation algebras of $\mathcal{W}$ and $\mathcal{S} $ are abelian Lie algebras or metabelian Lie algebras with explicit structure. In particular, we give the dimension formulae of the derivation algebras and outer derivation algebras of $\mathcal{W}$ and $\mathcal{S}.$ Thus we may make a comparison between the even parts of the (outer) superderivation algebras of $W$ and $S$ and the (outer) derivation algebras of the even parts of $W$ and $S,$ respectively.

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