Zobrazeno 1 - 10
of 261
pro vyhledávání: '"Stevanović, Dragan"'
Autor:
Radanović, Luka, Fellague, Abdelkadir, Ostojić, Dragutin, Stevanović, Dragan, Davidović, Tatjana
We consider the problem of characterizing graphs with the maximum spectral radius among the connected graphs with given numbers of vertices and edges. It is well-known that the candidates for extremal graphs are threshold graphs, but only a few parti
Externí odkaz:
http://arxiv.org/abs/2406.19209
We describe here how the recent Wagner's approach for applying reinforcement learning to construct examples in graph theory can be used in the search for critical graphs for small Ramsey numbers. We illustrate this application by providing lower boun
Externí odkaz:
http://arxiv.org/abs/2403.20055
We reimplement here the recent approach of Adam Zsolt Wagner [arXiv:2104.14516], which applies reinforcement learning to construct (counter)examples in graph theory, in order to make it more readable, more stable and much faster. The presented concep
Externí odkaz:
http://arxiv.org/abs/2403.18429
Autor:
Stevanović, Dragan, Ghebleh, Mohammad, Caporossi, Gilles, Vijayakumar, Ambat, Stevanović, Sanja
The triangle-degree of a vertex v of a simple graph G is the number of triangles in G that contain v. A simple graph is triangle-distinct if all its vertices have distinct triangle-degrees. Berikkyzy et al. [Discrete Math. 347 (2024) 113695] recently
Externí odkaz:
http://arxiv.org/abs/2401.10971
Autor:
Alizadeh, Yaser, Bašić, Nino, Damnjanović, Ivan, Došlić, Tomislav, Pisanski, Tomaž, Stevanović, Dragan, Xu, Kexiang
A nonnegative integer $p$ is realizable by a graph-theoretical invariant $I$ if there exist a graph $G$ such that $I(G) = p$. The inverse problem for $I$ consists of finding all nonnegative integers $p$ realizable by $I$. In this paper, we consider a
Externí odkaz:
http://arxiv.org/abs/2312.13083
Publikováno v:
MATCH Commun. Math. Comput. Chem. 90 (2023) 197-202
We note here that the problem of determining extremal values of Sombor index for trees with a given degree sequence fits within the framework of results by Hua Wang from [Cent. Eur. J. Math. 12 (2014) 1656-1663], implying that the greedy tree has the
Externí odkaz:
http://arxiv.org/abs/2211.11920
Autor:
Damnjanović, Ivan, Stevanović, Dragan
Publikováno v:
Publ. Inst. Math. 113 (2023) 57-65
Recently, Gutman [MATCH Commun. Math. Comput. Chem. 86 (2021) 11-16] defined a new graph invariant which is named the Sombor index $\mathrm{SO}(G)$ of a graph $G$ and is computed via the expression \[ \mathrm{SO}(G) = \sum_{u \sim v} \sqrt{\mathrm{de
Externí odkaz:
http://arxiv.org/abs/2211.05559
Publikováno v:
Linear Algebra Appl. 657 (2023) 163-196
We investigate the spectral properties of balanced trees and dendrimers, with a view toward unifying and improving the existing results. Here we find a semi-factorized formula for their characteristic polynomials. Afterwards, we determine their spect
Externí odkaz:
http://arxiv.org/abs/2210.08337
For a graph $G$, its energy $\mathcal{E}(G)$ is the sum of absolute values of the eigenvalues of its adjacency matrix, the matching number $\mu(G)$ is the number of edges in a maximum matching of $G$, while $\Delta$ is the maximum vertex degree of $G
Externí odkaz:
http://arxiv.org/abs/2111.15303