Displaying 101 – 120 of 362

Showing per page

Embedding 3 -homogeneous latin trades into abelian 2 -groups

Nicholas J. Cavenagh (2004)

Commentationes Mathematicae Universitatis Carolinae

Let T be a partial latin square and L be a latin square with T L . We say that T is a latin trade if there exists a partial latin square T ' with T ' T = such that ( L T ) T ' is a latin square. A k -homogeneous latin trade is one which intersects each row, each column and each entry either 0 or k times. In this paper, we show the existence of 3 -homogeneous latin trades in abelian 2 -groups.

Embedding complete ternary trees into hypercubes

S.A. Choudum, S. Lavanya (2008)

Discussiones Mathematicae Graph Theory

We inductively describe an embedding of a complete ternary tree Tₕ of height h into a hypercube Q of dimension at most ⎡(1.6)h⎤+1 with load 1, dilation 2, node congestion 2 and edge congestion 2. This is an improvement over the known embedding of Tₕ into Q. And it is very close to a conjectured embedding of Havel [3] which states that there exists an embedding of Tₕ into its optimal hypercube with load 1 and dilation 2. The optimal hypercube has dimension ⎡(log₂3)h⎤ ( = ⎡(1.585)h⎤) or ⎡(log₂3)h⎤+1....

Embedding properties of endomorphism semigroups

João Araújo, Friedrich Wehrung (2009)

Fundamenta Mathematicae

Denote by PSelf Ω (resp., Self Ω) the partial (resp., full) transformation monoid over a set Ω, and by Sub V (resp., End V) the collection of all subspaces (resp., endomorphisms) of a vector space V. We prove various results that imply the following: (1) If card Ω ≥ 2, then Self Ω has a semigroup embedding into the dual of Self Γ iff c a r d Γ 2 c a r d Ω . In particular, if Ω has at least two elements, then there exists no semigroup embedding from Self Ω into the dual of PSelf Ω. (2) If V is infinite-dimensional, then...

Currently displaying 101 – 120 of 362