*Article* **Secure Total Domination in Rooted Product Graphs**

### **Abel Cabrera Martínez, Alejandro Estrada-Moreno and Juan A. Rodríguez-Velázquez \***

Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Spain; abel.cabrera@urv.cat (A.C.M.); alejandro.estrada@urv.cat (A.E.-M.)

**\*** Correspondence: juanalberto.rodriguez@urv.cat

Received: 16 March 2020; Accepted: 14 April 2020; Published: 15 April 2020

**Abstract:** In this article, we obtain general bounds and closed formulas for the secure total domination number of rooted product graphs. The results are expressed in terms of parameters of the factor graphs involved in the rooted product.

**Keywords:** secure total domination; total domination; domination; rooted product graph
