A. Taherkhani

activity

20082026

collaborators

Showing math.COShow all

12 papers · 1 filter

math.CO2022

Partitioning of a graph into induced subgraphs not containing prescribed cliques

Yaser Rowshan, Ali Taherkhani

Let $K_{p}$ be a complete graph of order $p \geq 2$ . A $K_{p}$ -free $k$ -coloring of a graph $H$ is a partition of $V (H)$ into $V_{1}, V_{2} \dots, V_{k}$ such that $H [V_{i}]$ does not contain $K…

math.CO2020

A Catlin-type Theorem for Graph Partitioning Avoiding Prescribed Subgraphs

Yaser Rowshan, Ali Taherkhani

As an extension of the Brooks theorem, Catlin in 1979 showed that if $H$ is neither an odd cycle nor a complete graph with maximum degree $Δ (H)$ , then $H$ has a vertex $Δ (H)$ -color…

math.CO2019

Size and structure of large $(s, t)$ -union intersecting families

Ali Taherkhani

A family $\F$ of sets is said to be intersecting if any two sets in $\F$ have nonempty intersection. The celebrated Erd{\H o}s-Ko-Rado theorem determines the size and structure of…

math.CO2018

On the random version of the Erdős matching conjecture

Meysam Alishahi, Ali Taherkhani

The Kneser hypergraph $KG_{n, k}^{r}$ is an $r$ -uniform hypergraph with vertex set consisting of all $k$ -subsets of ${1, \dots, n}$ and any collection of $r$ vertices forms an…

math.CO2018

Extremal $G$ -free induced subgraphs of Kneser graphs

Meysam Alishahi, Ali Taherkhani

The Kneser graph $KG_{n, k}$ is a graph whose vertex set is the family of all $k$ -subsets of $[n]$ and two vertices are adjacent if their corresponding subsets are disjoint. T…

math.CO2017

Coloring Properties of Categorical Product of General Kneser Hypergraphs

Roya Abyazi Sani, Meysam Alishahi, Ali Taherkhani

More than 50 years ago Hedetniemi conjectured that the chromatic number of categorical product of two graphs is equal to the minimum of their chromatic numbers. This conjecture has…