Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Enveloping algebras with just infinite Gelfand-Kirillov dimension
AU - Iyudu, Natalia K.
AU - Sierra, Susan J.
PY - 2020/3/4
Y1 - 2020/3/4
N2 - Let $\mf g$ be the Witt algebra or the positive Witt algebra. It is well known that the enveloping algebra $U(\mf g )$ has intermediate growth and thus infinite Gelfand-Kirillov (GK-) dimension. We prove that the GK-dimension of $U(\mf g)$ is {\em just infinite} in the sense that any proper quotient of $U(\mf g)$ has polynomial growth.This proves a conjecture of Petukhov and the second named author for the positive Witt algebra.We also establish the corresponding results for quotients of the symmetric algebra $S(\mf g)$ by proper Poisson ideals.In fact, we prove more generally that any central quotient of the universal enveloping algebra of the Virasoro algebra has just infinite GK-dimension. We give several applications. In particular, we easily compute the annihilators of Verma modules over the Virasoro algebra.
AB - Let $\mf g$ be the Witt algebra or the positive Witt algebra. It is well known that the enveloping algebra $U(\mf g )$ has intermediate growth and thus infinite Gelfand-Kirillov (GK-) dimension. We prove that the GK-dimension of $U(\mf g)$ is {\em just infinite} in the sense that any proper quotient of $U(\mf g)$ has polynomial growth.This proves a conjecture of Petukhov and the second named author for the positive Witt algebra.We also establish the corresponding results for quotients of the symmetric algebra $S(\mf g)$ by proper Poisson ideals.In fact, we prove more generally that any central quotient of the universal enveloping algebra of the Virasoro algebra has just infinite GK-dimension. We give several applications. In particular, we easily compute the annihilators of Verma modules over the Virasoro algebra.
KW - Witt algebra
KW - positive Witt algebra
KW - Virasoro algebra
KW - Gelfand-Kirillov dimension
U2 - 10.4310/ARKIV.2020.v58.n2.a4
DO - 10.4310/ARKIV.2020.v58.n2.a4
M3 - Journal article
VL - 58
SP - 285
EP - 306
JO - Arkiv för Matematik
JF - Arkiv för Matematik
SN - 0004-2080
IS - 2
ER -