Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 296 https://internationalpubls.com Even Vertex Odd Edge Root Square Mean Labelling of Path Related Graphs K. N. Babu1, S. Meenakshi2 1 Research Scholar, Department of Mathematics, Vels Institute of Science, Technology and Advanced Studies (VISTAS), Associate Professor, Sri Malolan College of Arts and Science. Email: babumalolan@gmail.com 2 Research Supervisor, Vels Institute of Science, Technology and Advanced Studies (VISTAS), Chennai, India. Email: meenakshikarthikeyan@yahoo.in Article History: Received: 14-09-2024 Revised: 22-10-2024 Accepted: 02-11-2024 Abstract: Consider G be a graph with p vertices and q edges. A graph G is said to be even vertex odd edge root square mean labelling if there exist an injective map f : V(G) → {0,1,2,3, … , 2q} such that the induced edge labels are odd and distinct which can be obtained by f ∗ (e) = ⌈√ f(u)2 +f(v)2 2 ⌉ or ⌊√ f(u)2 +f(v)2 2 ⌋. Any graph which admits even vertex odd edge root square mean labelling then it is called as even vertex odd edge root square mean labelling graph. Keywords: EVOE – RSML, Graph, Ladder, Corona graph 1.Introduction: Throughout the work, we consider a simple graph. The terminology and the definitions of graph were followed in [1]. For a complete analysis of labeling studied by Gallian [1]. In 1960’s graph labeling was introduced by Rosa. Odd vertex even edge root square mean labeling discussed in [5] which motivated to construct the above said labeling pattern. We study a few paths related graphs which satisfies the above pattern. Mean labeling, root square mean and super root square mean labeling were discussed in [4,6,7,8]. 2 Preliminary: Definition 2.1 [5] A graph G is said to be odd vertex even edge root square mean labelling if there exist an injective map f : V(G) → {1,2,3, … , 2q + 1} such that the induced edge labels are odd and distinct which can be obtained by f ∗ (e) = ⌈√f(u)2 +f(v)2 2 ⌉ or ⌊√f(u)2 +f(v)2 2 ⌋ . Any graph which admits even vertex odd edge root square mean labelling then it is called as odd vertex even edge root square mean labelling graph. Definition 2.2 A graph G is said to be even vertex odd edge root square mean labelling if there exist an injective map f : V(G) → {0,1,2,3, … , 2q} such that the induced edge labels are odd and distinct which can be obtained by f ∗ (e) = ⌈√f(u)2 +f(v)2 2 ⌉ or ⌊√f(u)2 +f(v)2 2 ⌋ . Any graph which admits even vertex odd edge root square mean labelling then it is called as even vertex odd edge root square mean labelling graph. mailto:babumalolan@gmail.com Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 297 https://internationalpubls.com Definition 2.3 [6]: A graph G with p vertices and q edges, is a mean graph if there is an injective function f from the vertex set to { 1, 2, 3…q} when each edge uv is labelled with 𝑓(𝑢)+𝑓(𝑣) 2 if f(u)+f(v) is even and 𝑓(𝑢)+𝑓(𝑣)+1 2 if f(u)+f(v)+1 is odd then the labelling edges are distinct. Definition 2.4 [4]: A graph G with p vertices and q edges is called a Root Square Mean graph if is possible to label the vertices v with distinct labels f(x) from 1, 2, 3,… q+1 in such a way that when each edge e = uv is labelled with f(e ) =⌊√ ( f(u)2 +f(v)2 2 ) ⌋ or ⌈√ ( f(u)2 +f(v)2 2 ) ⌉ then each labels are distinct. Definition 2.5 [4]: The corona graph is obtained by taking one copy of path Pn and n copies of K1 then joining the ith vertex of Pn with an edge to every vertex in the ith copy of K1. It is denoted by Pn K1. Definition 2.6 [7]: TW(Pn) is a graph which is obtained from a path by identifying k1,2 to all the vertices of the path except one pendent vertex (Twing graph) A path with a least vertex is connected and has two terminal vertices while all other vertices have degree 2. Theorem 3.1: A path Pn is an even vertex odd edge root square mean labelling graph. Proof: Let G be a Path Pn, where V(G)= {ui:1≤ 𝑖 ≤ 𝑛} and E(G) = {ui, ui+1: 1≤ 𝑖 ≤ 𝑛 − 1} It is evident that G allows an even-vertex odd-edge root square mean labeling, as labels can be assigned to its vertices and edges in a sequential manner. Hence, G is classified as an even-vertex odd-edge root square mean graph. Illustration: Figure 1 shows G = P7 is Even vertex odd edge root square mean labelling. Figure 1 Even vertex odd edge root square mean labelling of P7 Theorem 3.2: Pn ʘ K1 is an even vertex odd edge root square mean labelling graph. Proof: Let G = Pn ʘ K1 The vertex set and edge set of G is defined as follows; V(G) = {ui , u′i ; 1≤ 𝑖 ≤ 𝑛} and E(G) = {ui u′i ; 1≤ 𝑖 ≤ 𝑛 and ui u′i+1 ; 1≤ 𝑖 ≤ 𝑛-1 } We define a map f: V(G) → {0,1, 2, 3…….2q}. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 298 https://internationalpubls.com The labelling pattern of vertices can be defined as follows; f (u2i−1) = 8i – 6 and f (u2i) = 8i – 4; 1≤ 𝑖 ≤ 𝑛 f (u′2i−1) = 8(i-1) and f (u′2i) = 8i-2; 1≤ 𝑖 ≤ 𝑛 Then the induced edge labels are f ′ ( uiu′i) = 4i – 3; 1 ≤ i ≤ n f ′ ( uiu′i+1) = 4i - 1 ; 1 ≤ i ≤ n − 1 Thus G = Pn ʘ K1 admit even vertex odd edge root square mean labelling graph. Illustration: Figure 2 illustrate the G = P4 ʘ K1 is even vertex odd edge root square mean labeling Figure 2 G = P4 ʘ K1 Theorem 3.3: Pn ʘ K1,2 is an even vertex odd edge root square mean labelling graph. Proof: Let G = Pn ʘ K1,2 is a graph formed by attaching a K1,2 (a star with one central vertex and two leaves) to each vertex of the path Pn. Let V(G) = {ui , u′i , u′′i ; 1≤ 𝑖 ≤ 𝑛} and E(G) = {ui u′i , ui u′′ i : 1≤ 𝑖 ≤ 𝑛 and ui u′i+1 : 1≤ 𝑖 ≤ 𝑛-1} This describes the standard labeling of the vertices and edges of G. We define a map f: 𝑉(𝐺) → {0, 1, 2, ……2q} by f(𝑢𝑖) = 6𝑖 – 4 ∶ 𝑖 ≤ 𝑖 ≤ 𝑛 f ( u′i ) = 6(i-1) and f ( u′′i ) = 6i - 2: 1≤ 𝑖 ≤ 𝑛 It is evident that the included edge labels are both odd and distinct. Hence G = Pn ʘ K1,2 is an even vertex odd edge root square mean labelling. Illustration: Figure 3 illustrate the G = P4 ʘ K1,2 is even vertex odd edge root square mean labeling Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 299 https://internationalpubls.com Figure 3 G = P4 ʘ K1,2 Theorem 3.4: The graph SLn is an even vertex odd edge mean square labelling graph. Proof: Let G = SLn Let the vertex set V(G) = {𝑢𝑖, 𝑣𝑖 ∶ 1 ≤ 𝑖 ≤ 𝑛} and edge set E (G) = { ui ui + 1 ∶ 1 ≤ i ≤ n − 1 vi vi + 1 ∶ 1 ≤ i ≤ n − 1 vi+2 vi ∶ 2 ≤ i ≤ n − 1 Define a map f: V(G) → {0,1, 2, ……2q} by f (u1) = 0, f(𝑣𝑛) = 2𝑞, further f (ui) = 6𝑖 – 10 ∶ 2 ≤ 𝑖 ≤ 𝑛, f (vi) = 6𝑖 – 2 ∶ 1 ≤ 𝑖 ≤ 𝑛 − 1 Then the induced edge labels are defined as follows; 𝑓′ (vivi+1) = 6𝑖 + 1∶ 1 ≤ 𝑖 ≤ 𝑛 − 2, 𝑓′ (vn−1vn) = 2𝑞 – 1 ∶ 1 ≤ 𝑖 ≤ 𝑛 − 2 and 𝑓′ (ui+1vi) = 6𝑖 − 3∶ 1 ≤ 𝑖 ≤ 𝑛 − 1. Hence, SLn admits even vertex odd edge mean square labelling graph. Illustration: Figure 4 illustrate the G = SL6 is even vertex odd edge root square mean labeling Figure 4 G = SL6 Theorem 3.5:[5] Let Gp be a graph formed by attaching a pendant edge to each internal vertex of a path. This graph Gp is an even vertex odd edge root mean square labelling graph. Proof: Let V(G) = { ui : 1 ≤ i ≤ n and u′i : 2 ≤ i ≤ n − 1 and Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 300 https://internationalpubls.com E(G) = { ui ui+1 : 1 ≤ i ≤ n − 2 ui u′i ∶ i = 2,3,4,5 . . . . n − 2 be the vertex set and edge set of G respectively. Define a map f: V(G) → { 0,2,4, . . . 2q} by f(u) where f(u) is determined based on the following two cases. Case 1: For n is odd f (ui) = 4(i -1) and f (u′i ) = 4i-6: i = 3, 5, … f (ui) = 4i -6 and f (u′i ) = 4(i-1): i = 2, 4, … The labels of the edges are then defined as follows f′(ui u′i ) = 4i – 5, i = 2, 4,…. n-1 and f′(ui ui+1 ) = 4i – 3, i = 1, 2 ,….n-1 Case 2: For n is even f (ui) = 4i -5 and f (u′i ) = 4i-6: i = 3, 5, … f (ui) = 4i -6 and f (u′i ) = 4(i-1): i = 2, 4, … Then the induced edge labels are defined as follows: f′(𝐮𝐢 𝐮′𝐢 ) = 4i – 5, i = 2, 4,….n-1 and f′(𝐮𝐢 𝐮𝐢+𝟏 ) = 4i – 3, i = 1, 2 ,….n-1 Hence f is an even vertex odd edge root square mean labelling of graph G. Therefore, G is classified as an even vertex odd edge root square mean labelling of graph with respect to f. Theorem 3.6: TW(Pn) is an even vertex odd edge root square mean labelling of graph. Proof: Let G = TW(Pn) V(G) = { ui : 1 ≤ i ≤ n and u′i and u′′i ∶ 2 ≤ i ≤ n E(G) = { uiui+1 : 1 ≤ i ≤ n − 1 and uiu′i and uiu′′ i ∶ 2 ≤ i ≤ n be the vertex set and edge set of G respectively. We define a map f: V(G) → 0,2,4, … 2q by f(u) = 0; f (u′i) = 2(i + j -1) i = 2 and j = 1, 2; f (u′i) = 6(i-1), i = 3,4, …n; f (u′′i) = 6i-10, i = 3, 4,…n Then the induced edge labels are defined as follows; f′(ui u′i ) = 6i – 9, f′(ui u′′i ) = 6i – 7, i = 2,4, …, n-1 and f′(ui ui+1 ) = 6i-5; i =1, 2,…n-1 Hence G is an even vertex odd edge root square mean labelling of graph since f is an even vertex odd edge root square mean labelling of graph G. Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 301 https://internationalpubls.com Illustration: Figure 5 illustrate the Gp on 6 vertices is even vertex odd edge root square mean labeling Figure 5 Gp on 6 vertices Theorem 3.5: K1,n an even vertex odd edge mean square labelling graph. if n ≤ 3. Proof: Let the vertex and edge sets of K1,n be defined as {u, v1, v2, … , vn}and {e1, e2, … , en} respectively. For n ≤ 3 , it exhibits an odd vertex even edge mean square labelling graph. This demonstrates the figures that are admitted as an odd vertex even edge mean square labelling graph. If n = 4 K 1 ,4 is not even vertex and odd edge labelling graph Since the graph depicts that the edge label 5 repeated two times If n = 5 Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 302 https://internationalpubls.com Since the graph depicts that the edge label 5 repeated two times In general, n > 3 Case (i) Let f(u) = 0, then f (ui) = {2, 4, 6, …, 2q} In this case, (0,6), (0, 8), will get same labels, which is contradiction to the definition. Case (ii) Let f(u) = 2q, then no edge can get the label 1. Since (0, 2q) = √2(q)2 = √2 q, which is not possible. Case (iii) If f(u) = {2 or 4 or 6 or …. 2(q-1)}, then we get the repetition of odd edge labelling. So, clearly one can check labelling of a graph. Theorem 3.6 A subdivision of Pn ʘ K1 is an even vertex odd edge root square mean labelling graph. Proof: The vertex set and edge set of, G, is defined as follows; V(G) = {ui ; 1≤ 𝑖 ≤ 𝑛} ∪ {vi 1 ≤ i ≤ n − 1} ∪ {ui , u′′i 1 ≤ i ≤ n} and E(G) ={ {ui u′i} ∪ {ui , u′′i } ∪ {ui vi} ∪ {ui vi + 1 } : 1≤ 𝑖 ≤ 𝑛-1 } We define a map f: V(G) → {0,1, 2, 3,…2q}. The labelling pattern of vertices can be defined as follows; f (ui) = 4i ; i = 1,2 f (ui) = 8i – 6 ; i = 3,4,5…, n-1 f(vi) = 6i ; i = 1,2 f (vi) = 8i – 2 ; i = 3,4,5…, n f (u′i) = 8i -6 ; i = 1,2 f(u′i) = 8(i – 8) ; i = 3,4,5…, n-1 f (u′′i) = 14(i-1); i = 1,2 f (u′′i) = 8i - 4; i = 3,4,5…, n-1 and f (un ) = 2(q − 1) Communications on Applied Nonlinear Analysis ISSN: 1074-133X Vol 32 No. 2s (2025) 303 https://internationalpubls.com Then the induced edge labels are f ′ (uivi) = 6i – 1; i = 1,2 f ′ (uivi) = 8i – 3; i = 3,4,5…, n-1 f ′(viui+1) = 8i – 1; 1≤ 𝑖 ≤ 𝑛-1 f ′ ( uiu′i) = 6i – 3; i = 1,2 f ′ ( uiu′i) = 8i – 7; i = 3,4,5…, n-1 f ′ ( u′iu′′i) = 12i – 11; i = 1,2 f ′ ( u′iu′′i) = 8i – 5; i = 3,4,5…, n-1 Thus, subdivision of G = Pn ʘ K1 admit even vertex odd edge root square mean labelling graph. Illustration: Figure 6 illustrate a subdivision of Pn ʘ K1 on 8 vertices is an even vertex odd edge root square mean labeling Figure 6 Pn ʘ K1 on 8 vertices Conclusion : In conclusion, this paper presents a new labeling pattern based on the root square mean, which has been successfully applied to path-related graphs, the subdivision of path corona graphs, and star graphs. The results demonstrate the effectiveness of this approach in enhancing graph labeling techniques and offer potential for further research in related areas. References [1] J.A.Gallian, ‘A dynamic survey of graphs labelling’,The electronic journal of combinatorics,18 (2015). [2] B.Gayathri and R.Gobi, ‘(k, d) even mean labelling of corona graphs, International Journal of Mathematics and Soft Computing, Vol.(1), 17-23, Aug (2011). [3] B.Gayathri and R.Gobi, ‘Necessary condition for mean labelling, In- ternational Journal of Engineering Science, Advanced Computing and Bio Technology’, Vol. 4(3), 43-52, July-Sep. (2013). [4] R.Ramdani, A.Y Fanisa, S. Gumilar, S Sabini, ‘Root square Mean la- belling of some graphs obtained from paths ‘ Journal of Physics Confer- ence Series (2021). [5] V. Senthilkumar , K. Venkatesan, “ Odd vertex even edge root square mean labelling graphs” Journal of Interdisciplinary Mathematics, Vol. 27 (2024), No. 5, pp. 1001–1008 [6] S.Somasundaram and R.Ponraj, ‘Mean labelling of graphs’, National academy science letters, 26, 210-213 (2003). [7] S. Sandiya, S. Somasundaram and S.Arun,‘Root square mean label- ling graphs’ Internal Journal Contemporary Math. Science, Vol.9(14), page no. 667-676 (2014). [8] K. Thirugnasambandam and K. Venkatesan,’ Super root square mean labelling of graphs’, International Journal of Mathematics and Soft Com- puting, Vol. 5(2), page no. 189-198 (2025).