Pointed irreducible bialgebras
Pointed irreducible bialgebras
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尖不可约双代数
DOI:
10.1016/0021-8693(79)90208-4
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发表时间:
1979
影响因子:
0.9
通讯作者:
Warren D. Nichols
中科院分区:
文献类型:
--
作者:
Warren D. Nichols
It is well-known [5, p. 274, Theorem 13.0. 11 that a pointed irreducible cocommutative bialgebra B over a field of characteristic zero is isomorphic as a bialgebra to U (P (B)), the universal enveloping algebra of the Lie algebra P (B) of primitives of B. One method of proof is first to show that B and U@‘(B)) are each coalgebra-isomorphic to the cofree pointed irreducible cocommutative coalgebra on the vector space P (B), and then to use these coalgebra isomorphisms to induce a bialgebra isomorphism.In this paper we prove a dual version of the above. Let B be a pointed irreducible commutative bialgebra over a field of characteristic zero. Write I for its augmentation ideal, and Q (B)= l/r2. Then B is isomorphic as a bialgebra to the appropriate universal object UIC (Q (B)). We first show that each is isomorphic as an algebra to Sym (Q (B)), and then use these algebra isomorphisms to induce a bialgebra isomorphism.