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

28 papers

cs.CC2026

Parameterized Complexity of Fair Coloring Problem

Ramin Javadi, Hossein Shokouhi

Given a graph $G = (V, E)$ , a (proper) $k$ -coloring for $G$ is a vertex coloring with $k$ colors such that every two adjacent vertices receive different colors. Suppose that the verte…

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…

cs.LG2026

Exact Recovery in the Data Block Model

Amir R. Asadi, Akbar Davoodi, Ramin Javadi +1

Community detection in networks is a fundamental problem in machine learning and statistical inference, with applications in social networks, biological systems, and communication…

cs.DM2025

On the structure of ( $4 K_{1}$ , $C_{4}$ , $P_{6}$ )-free graphs

Chính T. Hoàng, Ramin Javadi, Nicolas Trotignon

Determining the complexity of colouring ( $4 K_{1}, C_{4}$ )-free graph is a long open problem. Recently Penev showed that there is a polynomial-time algorithm to colour a ($4K_1, C_4, C_…

cs.CC2024

Parameterized Complexity of Fair Many-to-One Matchings

Ramin Javadi, Hossein Shokouhi

Given a bipartite graph $G = (U \cup V, E)$ , a left-perfect many-to-one matching is a subset $M \subseteq E$ such that each vertex in $U$ is incident with exactly one edge in $M$ . If $…

cs.CC2024

Parameterized Complexity of the Star Decomposition Problem

Sahab Hajebi, Ramin Javadi

A star of length $ℓ$ is defined as the complete bipartite graph $K_{1, ℓ}$ . In this paper we deal with the problem of edge decomposition of graphs into stars of varying l…

cs.DS2024

A High-Performance External Validity Index for Clustering with a Large Number of Clusters

Mohammad Yasin Karbasian, Ramin Javadi

This paper introduces the Stable Matching Based Pairing (SMBP) algorithm, a high-performance external validity index for clustering evaluation in large-scale datasets with a large…

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…

cs.CC2021

On the Parameterized Complexity of the Acyclic Matching Problem

Sahab Hajebi, Ramin Javadi

A matching is a set of edges in a graph with no common endpoint. A matching M is called acyclic if the induced subgraph on the endpoints of the edges in M is acyclic. Given a graph…

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…

cs.CC2019★ 1 cited

On the Parameterized Complexity of Sparsest Cut and Small-set Expansion Problems

Ramin Javadi, Amir Nikabadi

We present a parameterized dichotomy for the \textsc{ $k$ -Sparsest Cut} problem in weighted and unweighted versions. In particular, we show that the weighted \textsc{ $k$ -Sparsest Cu…

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 $g^{u}$ .

cs.DS2017

Multi-way sparsest cut problem on trees with a control on the number of parts and outliers

Ramin Javadi, Saleh Ashkboos

Given a graph, the sparsest cut problem asks for a subset of vertices whose edge expansion (the normalized cut given by the subset) is minimized. In this paper, we study a generali…

cs.DC2017

An Efficient Parallel Data Clustering Algorithm Using Isoperimetric Number of Trees

Ramin Javadi, Saleh Ashkboos

We propose a parallel graph-based data clustering algorithm using CUDA GPU, based on exact clustering of the minimum spanning tree in terms of a minimum isoperimetric criteria. We…

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