User profiles for Italo J. Dejter

Italo Dejter

Retired Professor of Mathematics, University of Puerto Rico, Rio Piedras
Verified email at upr.edu
Cited by 985

[HTML][HTML] Efficient dominating sets in Cayley graphs

IJ Dejter, O Serra - Discrete Applied Mathematics, 2003 - Elsevier
An independent set C of vertices in a graph is an efficient dominating set (or perfect code)
when each vertex not in C is adjacent to exactly one vertex in C. An E-chain is a countable …

To graph total coloring via efficient dominating sets

IJ Dejter - arXiv preprint arXiv:2405.08781, 2024 - arxiv.org
A totally efficient coloring of a regular graph with color set formed by one unit more than its
degree is a total coloring in which each vertex color class is an efficient dominating set, that is …

[PDF][PDF] On unitary Cayley graphs

IJ Dejter, RE Giudici - J. Combin. Math. Combin. Comput, 1995 - Citeseer
AssrRAcr. We deal with a family of undirected Cayley graphs X. which are unions of disjoint
Hamilton cycles, and some of their properties, where rz runs over the positive integers. It is …

Perfect domination in regular grid graphs

IJ Dejter - arXiv preprint arXiv:0711.4343, 2007 - arxiv.org
We show there is an uncountable number of parallel total perfect codes in the integer lattice
graph ${\Lambda}$ of $\R^2$. In contrast, there is just one 1-perfect code in ${\Lambda}$ …

Representation of Dyck words in tensors that zipper merge contiguous integer compositions

IJ Dejter - arXiv preprint arXiv:2107.04584, 2021 - arxiv.org
Let $0<k\in\mathbb{Z}$. We zipper-merge integer compositions with sums $k$ and $k+1$,
equal number of parts and initial entries equal at least to 1 and 2, respectively. This yields …

Efficient Domination and Total Colorings of Multiset Star Transposition Graphs

I Dejter - Available at SSRN 4733602 - papers.ssrn.com
… This generalizes Dejter-Serra work on vertex partitions of star Cayley graphs into EDSs. To
start with, the notion of EDS of a graph is generalized to that of an efficient dominating αset, …

Quasiperfect domination in triangular lattices

IJ Dejter - arXiv preprint arXiv:0903.3685, 2009 - arxiv.org
A vertex subset $S$ of a graph $G$ is a perfect (resp. quasiperfect) dominating set in $G$ if
each vertex $v$ of $G\setminus S$ is adjacent to only one vertex ($d_v\in\{1,2\}$ vertices) of …

[PDF][PDF] A numeral system for the middle-levels graphs.

IJ Dejter - Electron. J. Graph Theory Appl., 2021 - pdfs.semanticscholar.org
A sequence S of restricted-growth strings unifies the presentation of middle-levels graphs
Mk as follows, for 0< k∈ Z. Recall Mk is the subgraph in the Hasse diagram of the Boolean …

On a {K_4, K_ {2, 2, 2}}-ultrahomogeneous graph

IJ Dejter - arXiv preprint arXiv:0704.1493, 2007 - arxiv.org
The existence of a connected 12-regular $\{K_4,K_{2,2,2}\}$-ultrahomogeneous graph $G$
is established, (ie each isomorphism between two copies of $K_4$ or $K_{2,2,2}$ in $G$ …

A Dyck-word tree that controls all odd graphs

IJ Dejter - arXiv preprint arXiv:2306.14249, 2023 - arxiv.org
An infinite ordered tree $T$ exists that has as its vertex set a collection of tight restricted-growth
strings representing all Dyck words; these stand for the cyclic (resp., dihedral) classes …