\n \n \n
\n
\n\n \n \n Bergen, J.; and Wilson, M. C.\n\n\n \n \n \n \n \n X-inner automorphisms of semi-commutative quantum algebras.\n \n \n \n \n\n\n \n\n\n\n
Journal of Algebra, 220(1): 152-173. 1999.\n
\n\n
\n\n
\n\n
\n\n \n \n paper\n \n \n\n \n\n \n link\n \n \n\n bibtex\n \n\n \n \n \n abstract \n \n\n \n\n \n \n \n \n \n \n \n\n \n \n \n \n \n\n\n\n
\n
@article{bergen1999x,\n title={X-inner automorphisms of semi-commutative quantum algebras},\n author={Bergen, Jeffrey and Wilson, Mark C.},\n journal={Journal of Algebra},\n volume={220},\n number={1},\n pages={152-173},\n year={1999},\n publisher={Academic Press},\n keywords={algebra},\n url_Paper={https://www.sciencedirect.com/science/article/pii/S0021869399979279},\n abstract={Many important quantum algebras such as quantum symplectic space,\nquantum euclidean space, quantum matrices, $q$-analogs of the Heisenberg\nalgebra and the quantum Weyl algebra are semi-commutative. In addition,\nenveloping algebras $U(L_+)$ of even Lie color algebras are also\nsemi-commutative. In this paper, we generalize work of Montgomery and\nexamine the X-inner automorphisms of such algebras. The theorems and\nexamples in our paper show that for algebras $R$ of this type, the\nnon-identity X-inner automorphisms of $R$ tend to have infinite order.\nThus if $G$ is a finite group of automorphisms of $R$, then the action\nof $G$ will be X-outer and this immediately gives useful information\nabout crossed products $R∗_t G$.}\n}\n\n
\n
\n\n\n
\n Many important quantum algebras such as quantum symplectic space, quantum euclidean space, quantum matrices, $q$-analogs of the Heisenberg algebra and the quantum Weyl algebra are semi-commutative. In addition, enveloping algebras $U(L_+)$ of even Lie color algebras are also semi-commutative. In this paper, we generalize work of Montgomery and examine the X-inner automorphisms of such algebras. The theorems and examples in our paper show that for algebras $R$ of this type, the non-identity X-inner automorphisms of $R$ tend to have infinite order. Thus if $G$ is a finite group of automorphisms of $R$, then the action of $G$ will be X-outer and this immediately gives useful information about crossed products $R∗_t G$.\n
\n\n\n
\n\n\n
\n
\n\n \n \n Riley, D.; and Wilson, M. C.\n\n\n \n \n \n \n \n Associative algebras satisfying a semigroup identity.\n \n \n \n \n\n\n \n\n\n\n
Glasgow Mathematical Journal, 41(3): 453-462. 1999.\n
\n\n
\n\n
\n\n
\n\n \n \n paper\n \n \n\n \n\n \n link\n \n \n\n bibtex\n \n\n \n \n \n abstract \n \n\n \n\n \n \n \n \n \n \n \n\n \n \n \n \n \n\n\n\n
\n
@article{riley1999associative,\n title={Associative algebras satisfying a semigroup identity},\n author={Riley, D.M. and Wilson, Mark C.},\n journal={Glasgow Mathematical Journal},\n volume={41},\n number={3},\n pages={453-462},\n year={1999},\n publisher={Cambridge University Press},\n keywords={algebra},\n url_Paper={https://www.cambridge.org/core/journals/glasgow-mathematical-journal/article/associative-algebras-satisfying-a-semigroup-identity/89A9FE38678C0635AE59E0B3286291CA},\n abstract={Denote by $(R,\\cdot)$ the multiplicative semigroup of an associative\nalgebra $R$ over an infinite field, and let $(R,\\circ)$ represent $R$\nwhen viewed as a semigroup via the circle operation $x\\circ y=x+y+xy$.\nIn this paper we characterize the existence of an identity in these\nsemigroups in terms of the Lie structure of $R$. Namely, we prove that\nthe following conditions on $R$ are equivalent: the semigroup\n$(R,\\circ)$ satisfies an identity; the semigroup $(R,\\cdot)$ satisfies a\nreduced identity; and, the associated Lie algebra of $R$ satisfies the\nEngel condition. When $R$ is finitely generated these conditions are\neach equivalent to $R$ being upper Lie nilpotent.}\n}\n\n
\n
\n\n\n
\n Denote by $(R,·)$ the multiplicative semigroup of an associative algebra $R$ over an infinite field, and let $(R,∘)$ represent $R$ when viewed as a semigroup via the circle operation $x∘ y=x+y+xy$. In this paper we characterize the existence of an identity in these semigroups in terms of the Lie structure of $R$. Namely, we prove that the following conditions on $R$ are equivalent: the semigroup $(R,∘)$ satisfies an identity; the semigroup $(R,·)$ satisfies a reduced identity; and, the associated Lie algebra of $R$ satisfies the Engel condition. When $R$ is finitely generated these conditions are each equivalent to $R$ being upper Lie nilpotent.\n
\n\n\n
\n\n\n
\n
\n\n \n \n Riley, D.; and Wilson, M. C.\n\n\n \n \n \n \n \n Group algebras and enveloping algebras with nonmatrix and semigroup identities.\n \n \n \n \n\n\n \n\n\n\n
Communications in Algebra, 27(7): 3545-3556. 1999.\n
\n\n
\n\n
\n\n
\n\n \n \n paper\n \n \n\n \n\n \n link\n \n \n\n bibtex\n \n\n \n \n \n abstract \n \n\n \n\n \n \n \n \n \n \n \n\n \n \n \n \n \n\n\n\n
\n
@article{riley1999group,\n title={Group algebras and enveloping algebras with nonmatrix and semigroup identities},\n author={Riley, D.M. and Wilson, Mark C.},\n journal={Communications in Algebra},\n volume={27},\n number={7},\n pages={3545-3556},\n year={1999},\n publisher={Taylor \\& Francis},\n keywords={algebra},\n url_Paper={https://www.tandfonline.com/doi/abs/10.1080/00927879908826645},\n abstract={Let $K$ be a field of characteristic $p>0$. Denote by $\\omega(R)$ the\naugmentation ideal of either a group algebra $R=K[G]$ or a restricted\nenveloping algebra $R=u(L)$ over $K$. We first characterize those $R$\nfor which $\\omega(R)$ satisfies a polynomial identity not satisfied by\nthe algebra of all $2\\times 2$ matrices over $K$. Then, we examine those\n$R$ for which $\\omega(R)$ satisfies a semigroup identity (that is, a\npolynomial identity which can be written as the difference of two\nmonomials).}\n}\n\n
\n
\n\n\n
\n Let $K$ be a field of characteristic $p>0$. Denote by $ω(R)$ the augmentation ideal of either a group algebra $R=K[G]$ or a restricted enveloping algebra $R=u(L)$ over $K$. We first characterize those $R$ for which $ω(R)$ satisfies a polynomial identity not satisfied by the algebra of all $2× 2$ matrices over $K$. Then, we examine those $R$ for which $ω(R)$ satisfies a semigroup identity (that is, a polynomial identity which can be written as the difference of two monomials).\n
\n\n\n
\n\n\n
\n
\n\n \n \n Riley, D.; and Wilson, M. C.\n\n\n \n \n \n \n \n Associative rings satisfying the Engel condition.\n \n \n \n \n\n\n \n\n\n\n
Proceedings of the American Mathematical Society, 127(4): 973-976. 1999.\n
\n\n
\n\n
\n\n
\n\n \n \n paper\n \n \n\n \n\n \n link\n \n \n\n bibtex\n \n\n \n \n \n abstract \n \n\n \n\n \n \n \n \n \n \n \n\n \n \n \n \n \n\n\n\n
\n
@article{riley1999associative,\n title={Associative rings satisfying the Engel condition},\n author={Riley, D.M. and Wilson, Mark C.},\n journal={Proceedings of the American Mathematical Society},\n volume={127},\n number={4},\n pages={973-976},\n year={1999},\n keywords={algebra},\n url_Paper={https://www.ams.org/journals/proc/1999-127-04/S0002-9939-99-04643-2/S0002-9939-99-04643-2.pdf},\n abstract={Let $C$ be a commutative ring, and let $R$ be an associative $C$-algebra\ngenerated by elements $\\{x_1,\\ldots,x_d\\}$. We show that if $R$\nsatisfies the Engel condition of degree $n$ then $R$ is upper Lie\nnilpotent of class bounded by a function that depends only on $d$ and\n$n$. We deduce that the Engel condition in an arbitrary associative ring\nis inherited by its group of units, and implies a semigroup identity.}\n}\n\n
\n
\n\n\n
\n Let $C$ be a commutative ring, and let $R$ be an associative $C$-algebra generated by elements $\\{x_1,…,x_d\\}$. We show that if $R$ satisfies the Engel condition of degree $n$ then $R$ is upper Lie nilpotent of class bounded by a function that depends only on $d$ and $n$. We deduce that the Engel condition in an arbitrary associative ring is inherited by its group of units, and implies a semigroup identity.\n
\n\n\n
\n\n\n\n\n\n