# On a general form of join matrices associated with incidence functions

Authors: Korkee, Ismo1; Haukkanen, Pentti2

Source: aequationes mathematicae, Volume 75, Numbers 1-2, March 2008 , pp. 29-42(14)

Publisher: Springer

OR

Price: \$47.00 plus tax (Refund Policy)

Abstract:

Let $$(P,\leq) = (P, \vee)$$ be a join-semilattice with finite principal order filters and let $$\Psi_{\vee}$$ denote the function on P  × P defined by where f and g are incidence functions of P and h is a complex-valued function on P. We calculate the determinant and the inverse of the matrix $$[\Psi_{\vee}(x_i, x_j)]$$ , where S = {x 1, x 2,...,x n } is a join-closed subset of P and (x i , x j S, x i  ≤ x j  ≤ z) ⇒ f(x i , z) = f(x j , z) holds for all zP.

As special cases we obtain formulae for join matrices $$([S]_h)_{ij} = h(x_i \vee x_j)$$ . The determinant formulae obtained for join matrices are known in the literature, whereas the inverse formulae are new. We also obtain new results for LCM and LCUM matrices, which are number-theoretic special cases of join matrices.

Document Type: Research Article

Affiliations: 1: Department of Mathematics, Statistics and Philosophy, University of Tampere, FI-33014, Tampere, Finland, Email: ismo.korkee@uta.fi 2: Department of Mathematics, Statistics and Philosophy, University of Tampere, FI-33014, Tampere, Finland, Email: pentti.haukkanen@uta.fi

Publication date: March 1, 2008

Related content

#### Key

Free content
New content
Open access content
Subscribed content
Free trial content

#### Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. Print this page