RUS  ENG
Full version
JOURNALS // Vladikavkazskii Matematicheskii Zhurnal // Archive

Vladikavkaz. Mat. Zh., 2020 Volume 22, Number 2, Pages 48–52 (Mi vmj723)

This article is cited in 1 paper

Tosha-degree equivalence signed graphs

R. Rajendraa, P. Siva Kota Reddyb

a Mangalore University, Mangalagangothri 574199, Karnataka, India
b Sri Jayachamarajendra College of Engineering, JSS Science and Technology University, Mysuru 570 006, Karnataka, India

Abstract: The Tosha-degree of an edge $\alpha $ in a graph $\Gamma$ without multiple edges, denoted by $T(\alpha)$, is the number of edges adjacent to $\alpha$ in $\Gamma$, with self-loops counted twice. A signed graph (marked graph) is an ordered pair $\Sigma=(\Gamma,\sigma)$ ($\Sigma =(\Gamma, \mu)$), where $\Gamma=(V,E)$ is a graph called the underlying graph of $\Sigma$ and $\sigma : E \rightarrow \{+,-\}$ ($\mu : V \rightarrow \{+,-\}$) is a function. In this paper, we define the Tosha-degree equivalence signed graph of a given signed graph and offer a switching equivalence characterization of signed graphs that are switching equivalent to Tosha-degree equivalence signed graphs and $ k^{th}$ iterated Tosha-degree equivalence signed graphs. It is shown that for any signed graph $\Sigma$, its Tosha-degree equivalence signed graph $T(\Sigma)$ is balanced and we offer a structural characterization of Tosha-degree equivalence signed graphs.

Key words: signed graphs, balance, switching, Tosha-degree of an edge, Tosha-degree equivalence signed graph, negation.

UDC: 519.17

MSC: 05C22

Received: 24.06.2019

Language: English

DOI: 10.46698/m4113-7350-5686-a



© Steklov Math. Inst. of RAS, 2024