Relating the independence number and the dissociation number
نویسندگان
چکیده
The independence number α ( G ) $\alpha (G)$ and the dissociation diss $\text{diss}(G)$ of a graph $G$ are largest orders induced subgraphs maximum degree at most 0 1, respectively. We consider possible improvements obvious inequality 2 ≥ $2\alpha (G)\ge \text{diss}(G)$ . For connected cubic graphs distinct from K 4 ${K}_{4}$ , we show 5 3 $5\alpha 3\,\text{diss}(G)$ describe rich interesting structure extremal in detail. bipartite graphs, and, more generally, triangle-free also obtain improvements. subcubic though, cannot be improved general, characterize all graphs.
منابع مشابه
On the chromatic number and independence number of hypergraph products
The hypergraph product G2H has vertex set V (G) × V (H), and edge set {e × f : e ∈ E(G), f ∈ E(H)}, where × denotes the usual cartesian product of sets. We construct a hypergraph sequence {Gn} for with χ(Gn) → ∞ and χ(Gn2Gn) = 2 for all n. This disproves a conjecture of Berge and Simonovits [2]. On the other hand, we show that if G and H are hypergraphs with infinite chromatic number, then the ...
متن کاملThe relationship between the distinguishing number and the distinguishing index with detection number of a graph
This article has no abstract.
متن کاملOn the Ramsey-Turán number with small s-independence number
Let s be an integer, f = f(n) a function, and H a graph. Define the Ramsey-Turán number RTs(n,H, f) as the maximum number of edges in an H-free graph G of order n with αs(G) < f , where αs(G) is the maximum number of vertices in a Ks-free induced subgraph of G. The Ramsey-Turán number attracted a considerable amount of attention and has been mainly studied for f not too much smaller than n. In ...
متن کاملHamiltonian properties and the bipartite independence number
By using the notion of compatibility of subgraphs with a perfect matching developed for digraphs in [1], we show that if, in a balanced bipartite graph G of minimum degree 6, the maximum cardinality ebip of a balanced independent subset satisfies ~bip ~< 26-4, then G is hamiltonian-biconnected, and if Ctbip ~< 26-2, G contains a hamiltonian path. Moreover, we give some properties of balanced bi...
متن کاملThe critical independence number and an independence decomposition
An independent set Ic is a critical independent set if |Ic|−|N(Ic)| ≥ |J | − |N(J)|, for any independent set J . The critical independence number of a graph is the cardinality of a maximum critical independent set. This number is a lower bound for the independence number and can be computed in polynomial-time. Any graph can be decomposed into two subgraphs where the independence number of one s...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Graph Theory
سال: 2023
ISSN: ['0364-9024', '1097-0118']
DOI: https://doi.org/10.1002/jgt.22965