Search arXivSearch

arXiv · 1911.04516

Boolean lattices in finite alternating and symmetric groups

Abstract

Given a group $G$ and a subgroup $H$, we let $\mathcal{O}_G(H)$ denote the lattice of subgroups of $G$ containing $H$. This paper provides a classification of the subgroups $H$ of $G$ such that $\mathcal{O}_{G}(H)$ is Boolean of rank at least $3$, when $G$ is a finite alternating or symmetric group. Besides some sporadic examples and some twisted versions, there are two different types of such lattices. One type arises by taking stabilizers of chains of regular partitions, and the other type arises by taking stabilizers of chains of regular product structures. As an application, we prove in this case a conjecture on Boolean overgroup lattices, related to the dual Ore's theorem and to a problem of Kenneth Brown.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Andrea Lucchini, Mariapia Moscatiello, Sebastien Palcoux, Pablo Spiga. 2019-11-11. Boolean lattices in finite alternating and symmetric groups. https://doi.org/10.1017/fms.2020.49

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Strongly Doubly Reversible Pairs in Quaternionic Unitary Group of Signature $(n,1)$

Let $\mathrm{PSp}(n,1)$ denote the isometry group of quaternionic hyperbolic $n$--space $\h^n$. A pair $(g_1,g_2)\in\mathrm{PSp}(n,1)^2$ is \emph{strongly doubly reversible} if $(g_1,g_2)$ and $(g_1^{-1},g_2^{-1})$ are simultaneously conjugate by an involution. Equivalently, there exist involutions $i_1,i_2,i_3\in\mathrm{PSp}(n,1)$ such that $g_1=i_1i_2$ and $g_2=i_1i_3$. We prove that the set of strongly doubly reversible pairs has Haar measure zero in $\mathrm{PSp}(n,1)\times\mathrm{PSp}(n,1)$. The same conclusion holds for $\mathrm{PSp}(n)\times\mathrm{PSp}(n)$ and $\mathrm{SU}(n,1)\times\mathrm{SU}(n,1)$ for $n\ge2$, and for $\mathrm{SO}_0(n,1)\times\mathrm{SO}_0(n,1)$ and $\mathrm{SO}(n+1)\times\mathrm{SO}(n+1)$ for $n\ge4$. In the compact rank-one case, every pair in $\mathrm{PSp}(1)$ is strongly doubly reversible, which gives a short proof of the theorem of Basmajian and Maskit that every pair in $\mathrm{SO}(4)$ is strongly doubly reversible. For hyperbolic pairs, we prove that double reversibility and strong double reversibility are equivalent in $\mathrm{PSp}(1,1)$. In higher dimension, we prove the same implication when one member of the pair is regular, with pairwise distinct non-real unit eigenvalue classes. Finally, in $\mathrm{PSp}(1,1)$, for a hyperbolic element in normal form, we give a complete explicit matrix criterion characterizing all elements that form a strongly doubly reversible pair with it.

math.GR

Non-split sharply 2- and 3-transitive groups in SL_n(\mathbb Z)

We prove that $\mathrm{SL}_3(\mathbb{Z})$ contains a non-split sharply 2-transitive subgroup, answering a question of Glasner and Gulko. We also prove that $\mathrm{SL}_4(\mathbb{Z})$ contains a non-split sharply 3-transitive subgroup, but that $\mathrm{SL}_3(\mathbb{Z})$ does not contain an infinite sharply 3-transitive subgroup.

math.GR

The Fourth Continuous Bounded Cohomology of the Complex Symplectic Group

We prove that $H_{\mathrm{cb}}^4(\Sp(4,\CC);\RR)=0$. Together with Blatz's secondary stability and the rank-one theorem of Bucher--Savini, this gives degree-four vanishing for all complex symplectic and odd complex orthogonal groups. In normalized symplectic Gram coordinates, we establish a bounded-primitive estimate and compute the measurable cohomology of the projective action. An explicit rational cocycle has divergent periods on a family of finite orbit cycles of uniformly bounded $\ell^1$-mass. A two-cone averaging construction extends the period estimate to measurable cochains and excludes bounded representatives of every nonzero degree-four measurable action class.

math.GR