R. Javadi

activity

20082026

most citedOn The Isoperimetric Spectrum of Graphs and Its Approximations

15 citations · 26 across the 27 of their papers we have counts for

collaborators

Showing math.COShow all

16 papers · 1 filter

math.CO2026

The multicolor induced size-Ramsey number of long subdivisions

Ramin Javadi, Yoshiharu Kohayakawa, Meysam Miralaei

For a positive integer $k$ and a graph $H$ , the $k$ -color induced size-Ramsey number $R^_{ind} (H, k)$ is the minimum integer $m$ for which there exists a graph $G$ wi…

math.CO2026

The Multicolor Size-Ramsey Number of Bipartite Long Subdivisions

Ramin Javadi, Yoshiharu Kohayakawa, Meysam Miralaei

For a positive integer $r$ , the $r$ -color size-Ramsey number~ $R_{r} (H)$ of a graph $H$ is the minimum number of edges in a graph $G$ such that every $r$ -edge coloring of $G…

math.CO2024

A Conjecture on Rainbow Hamiltonian Cycle Decomposition

Ramin Javadi, Meysam Miralaei

Wu in 1999 conjectured that if $H$ is a subgraph of the complete graph $K_{2 n + 1}$ with $n$ edges, then there is a Hamiltonian cycle decomposition of $K_{2 n + 1}$ such that each edge…

math.CO2022

The Game of Cops and Robber on (Claw, Even-hole)-free Graphs

Ramin Javadi, Ali Momeni

In this paper, we study the game of cops and robber on the class of graphs with no even hole (induced cycle of even length) and claw (a star with three leaves). The cop number of a…

math.CO2021

On a Conjecture of Erd\H os on Size Ramsey Number of Star Forests

Akbar Davoodi, Ramin Javadi, Azam Kamranian +1

Given graphs $F_{1}, F_{2}$ and $G$ , we say that $G$ is Ramsey for $(F_{1}, F_{2})$ and we write $G \to (F_{1}, F_{2})$ , if for every edge coloring of $G$ by red and blue, there is eithe…

math.CO2021

Multicolor Size-Ramsey Number of Cycles

Ramin Javadi, Meysam Miralaei

Given a positive integer $r$ , the $r$ -color size-Ramsey number of a graph $H$ , denoted by $R^(H, r)$ , is the smallest integer $m$ for which there exists a graph $ G…

math.CO2019

On the packing for triples

Ramin Javadi, Ehsan Poorhadi, Farshad Fallah

For positive integers $n \geq k \geq t$ , a collection $B$ of $k$ -subsets of an $n$ -set $X$ is called a $t$ -packing if every $t$ -subset of $X$ appears in at most one s…

math.CO2018

The spectrum for large sets of $(3, λ)$ -GDDs of type $g^{u}$

X. Niu, H. Cao, R. Javadi

In this paper, we completely solve the existence of large sets of $(3, λ)$ -GDDs of type $g^{u}$ and the existence of a simple $(3, λ)$ -GDD of type $g^{u}$ .

math.CO2017

On a question of Erdos and Faudree on the size Ramsey numbers

Ramin Javadi, Gholamreza Omidi

For given simple graphs $G_{1}$ and $G_{2}$ , the size Ramsey number $R^(G_{1}, G_{2})$ is the smallest positive integer $m$ , where there exists a graph $G$ with $m$ edges such that in…

math.CO2017

On the size-Ramsey number of cycles

Ramin Javadi, Farideh Khoeini, Gholam Reza Omidi +1

For given graphs $G_{1}, \dots, G_{k}$ , the size-Ramsey number $R^(G_{1}, \dots, G_{k})$ is the smallest integer $m$ for which there exists a graph $H$ on $m$ edges such that in every $…

math.CO2016

Decompositions of complete uniform multi-hypergraphs into Berge paths and cycles of arbitrary lengths

Ramin Javadi, Afsaneh Khodadadpour, Gholamreza Omidi

In 1981, Alspach conjectured that the complete graph $K_{n}$ could be decomposed into cycles of arbitrary lengths, provided that the obvious necessary conditions would hold. This…

math.CO2016★ 5 cited

Edge Clique Cover of Claw-free Graphs

Ramin Javadi, Sepehr Hajebi

The smallest number of cliques, covering all edges of a graph $G$ , is called the (edge) clique cover number of $G$ and is denoted by $cc (G)$ . It is an easy observation that f…

math.CO2015

Sigma clique covering of graphs

Akbar Davoodi, Ramin Javadi, Behnaz Omoomi

The sigma clique cover number (resp. sigma clique partition number) of graph G, denoted by scc(G) (resp. scp(G)), is defined as the smallest integer k for which there exists a coll…

math.CO2014★ 1 cited

Pairwise Balanced Designs and Sigma Clique Partitions

Akbar Davoodi, Ramin Javadi, Behnaz Omoomi

In this paper, we are interested in minimizing the sum of block sizes in a pairwise balanced design, where there are some constraints on the size of one block or the size of the la…

math.CO2012★ 1 cited

Local Clique Covering of Graphs

Ramin Javadi, Zeinab Maleki, Behnaz Omoomi

A k-clique covering of a simple graph G, is an edge covering of G by its cliques such that each vertex is contained in at most k cliques. The smallest k for which G admits a k-cliq…

math.CO2008★ 15 cited

On The Isoperimetric Spectrum of Graphs and Its Approximations

Amir Daneshgar, Hossein Hajiabolhassan, Ramin Javadi

In this paper we consider higher isoperimetric numbers of a (finite directed) graph. In this regard we focus on the $n$ th mean isoperimetric constant of a directed graph as the min…