Work

Component factors and degree sum conditions in graphs

Year: 2024
Type: article
Abstract: For a set π’œ of connected graphs, an π’œ-factor is a spanning subgraph of a graph, whose connected components are isomorphic to graphs from the set π’œ. An π’œ-factor is also referred as a component factor. A graph G is called an (π’œ, m)-factor deleted graph if for every Eβ€² βŠ† E(G) with |Eβ€²| = m, G βˆ’ Eβ€² admits an π’œ-factor. A graph G is called an (π’œ, l)-factor critical graph if for every Vβ€² βŠ† V (G) with |Vβ€²| = l, G βˆ’ Vβ€² admits an π’œ-factor. Let m, l and k be three positive integers with k β‰₯ 2, and write β„± = {P2, C3, P5, 𝒯 (3)} and β„‹ = {K1,1, K1,2, . . . , K1,k, 𝒯 (2k + 1)}, where 𝒯 (3) and 𝒯 (2k + 1) are two special families of trees. Inspired by finding a sufficient condition to check for the existence of path-factors with some special restraints, we focus on the sufficient conditions based on a graphic parameter called degree sum: σκ(G) = min⁑XβŠ†V(G) {Ξ£x∈XdG(x):X is an independent set of k vertices}. In this article, we verify that: (i) an (l + 2)-connected graph G of order n is an (β„±, l)-factor critical graph if Οƒ3(G) β‰₯ 6n+9l/5 ; (ii) a (2m + 1)-connected graph G of order n is an (β„±, m)-factor deleted graph if Οƒm+2(G) β‰₯ 6/5n ; (iii) an (l + 2)-connected graph G of order n is an (β„‹, l)-factor critical graph if Οƒ2k+1(G) β‰₯ 6n+(6k+3)l/2k+3 ; (iv) a (2m + 1)-connected graph G of order n is an (β„‹, m)-factor deleted graph if Οƒm+2(G) β‰₯ 6n/2k+3 .
Language: English
Open Access status: diamond
OpenAlex ID: W4401687526
FWCI: 0.196
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Cited by: 1
Related to: 10