On Boolean intervals of finite groups

Balodi, Mamta and Paleoux, Sebastien (2018) On Boolean intervals of finite groups. In: JOURNAL OF COMBINATORIAL THEORY SERIES A, 157 . pp. 49-69.

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Abstract

We prove a dual version of circle divide ystein Ore's theorem on distributive intervals in the subgroup lattice of finite groups, having a nonzero dual Euler totient phi. For any Boolean group-complemented interval, we observe that phi = phi not equal 0 by the original Ore's theorem. We also discuss some applications in representation theory. We conjecture that cp is always nonzero for Boolean intervals. In order to investigate it, we prove that for any Boolean group-complemented interval H, G], the graded coset poset P=C (H,G) is Cohen Macaulay and the nontrivial reduced Betti number of the order complex Delta(P) is phi, so nonzero. We deduce that these results are true beyond the group-complemented case with vertical bar G : H vertical bar < 32. One observes that they are also true when H is a Borel subgroup of G. (C) 2018 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF COMBINATORIAL THEORY SERIES A
Publisher:	ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
Additional Information:	Copy right for this article belong to ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
Department/Centre:	Division of Physical & Mathematical Sciences > Mathematics
Date Deposited:	08 May 2018 19:04
Last Modified:	08 May 2018 19:04
URI:	http://eprints.iisc.ac.in/id/eprint/59807

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