Some Schemes Related to the Commuting Variety
نویسنده
چکیده
The commuting variety is the pairs of n × n matrices (X, Y) such that XY = YX. We introduce the diagonal commutator scheme, { (X, Y) : XY − YX is diagonal } , which we prove to be a reduced complete intersection, one component of which is the commuting variety. (We conjecture there to be only one other component.) The diagonal commutator scheme has a flat degeneration to the scheme { (X, Y) : XY lower triangular, YX upper triangular } , which is again a reduced complete intersection, this time with n! components (one for each permutation). The degrees of these components give interesting invariants of permutations.
منابع مشابه
Maximal subsets of pairwise non-commuting elements of some finite p-groups
Let G be a group. A subset X of G is a set of pairwise noncommuting elements if xy ̸= yx for any two distinct elements x and y in X. If |X| ≥ |Y | for any other set of pairwise non-commuting elements Y in G, then X is said to be a maximal subset of pairwise non-commuting elements. In this paper we determine the cardinality of a maximal subset of pairwise non-commuting elements in any non-abelian...
متن کاملOn the commuting graph of some non-commutative rings with unity
Let $R$ be a non-commutative ring with unity. The commuting graph of $R$ denoted by $Gamma(R)$, is a graph with a vertex set $Rsetminus Z(R)$ and two vertices $a$ and $b$ are adjacent if and only if $ab=ba$. In this paper, we investigate non-commutative rings with unity of order $p^n$ where $p$ is prime and $n in lbrace 4,5 rbrace$. It is shown that, $Gamma(R)$ is the disjoint ...
متن کاملSome notes on ``Common fixed point of two $R$-weakly commuting mappings in $b$-metric spaces"
Very recently, Kuman et al. [P. Kumam, W. Sintunavarat, S. Sedghi, and N. Shobkolaei. Common Fixed Point of Two $R$-Weakly Commuting Mappings in $b$-Metric Spaces. Journal of Function Spaces, Volume 2015, Article ID 350840, 5 pages] obtained some interesting common fixed point results for two mappings satisfying generalized contractive condition in $b$-metric space without the assumption of the...
متن کاملPairwise non-commuting elements in finite metacyclic $2$-groups and some finite $p$-groups
Let $G$ be a finite group. A subset $X$ of $G$ is a set of pairwise non-commuting elements if any two distinct elements of $X$ do not commute. In this paper we determine the maximum size of these subsets in any finite non-abelian metacyclic $2$-group and in any finite non-abelian $p$-group with an abelian maximal subgroup.
متن کامل