<?xml version="1.0" encoding="UTF-8"?>
<article article-type="Research Article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher">journal-of-discrete-mathematical-sciences-and-cryptography</journal-id>
      <journal-title-group>
        <journal-title>Journal of Discrete Mathematical Sciences and Cryptography</journal-title>
      </journal-title-group>
      <issn publication-format="electronic">2169-0065</issn>
      <issn publication-format="print">0972-0529</issn>
      <publisher>
        <publisher-name>Taru Publications</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.47974/JDMSC-2701</article-id>
      <title-group>
        <article-title>In-domination and out-domination numbers of unidirectional graphs</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Kumar</surname>
            <given-names>Sanal</given-names>
          </name>
          <aff>Department of Sciences and Mathematics, Faculty of Mathematics, University of Technology and Applied Sciences, Sultanate of Oman</aff>
        </contrib>
      </contrib-group>
      <volume>29</volume>
      <issue>7</issue>
      <fpage>2897</fpage>
      <lpage>2904</lpage>
      <pub-date date-type="pub">
        <day>17</day>
        <month>07</month>
        <year>2026</year>
      </pub-date>
      <abstract>
        <p>The diverging unidirectional star graph is the unidirectional star graph with n+1 nodes(vertices) and n arcs, n nodes of in-degree 1 and out-degree 0. The converging unidirectional graph consisting of n+1 vertices and n arcs, where n vertices have out-degree one and in-degree zero, with all arcs oriented towards the single central vertex. A diverging unidirectional perfect binary tree is a directed tree where each internal vertex, except for the root, has an out-degree of two and in-degree of one, with all leaves at the same depth; conversely, a converging unidirectional perfect tree has the opposite structure. Here, we investigate the in-domination and out-domination numbers associated with these classes of directed graph. Explicit expressions for the same numbers are derived for the afore mentioned families of graphs as well as for unidirectional non-homogeneous super caterpillar graphs.</p>
      </abstract>
      <kwd-group>
        <kwd>Digraph</kwd>
        <kwd>Domination number</kwd>
        <kwd>In-domination</kwd>
        <kwd>Out-domination</kwd>
        <kwd>Unidirectional graph</kwd>
      </kwd-group>
      <custom-meta-group>
        <custom-meta>
          <meta-name>access</meta-name>
          <meta-value>open</meta-value>
        </custom-meta>
        <custom-meta>
          <meta-name>retracted</meta-name>
          <meta-value>no</meta-value>
        </custom-meta>
      </custom-meta-group>
    </article-meta>
  </front>
</article>
