C. Y. Ku

activity

20082025

D

-graphs for Nonzero Roots of the Matching Polynomial

3 citations · 4 across the 16 of their papers we have counts for

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16 papers · 1 filter

math.CO2025

An analogue of the Erd{\H o}s Matching Conjecture for permutations with fixed number of cycles

Cheng Yeaw Ku, Kok Bin Wong

Let $S_{n}$ denote the set of permutations of $[n] = {1, 2, \dots, n}$ . For each integer $k \geq 1$ , let $S_{n, k}$ be the set of all permutations of $[n]$ with exactly $k$ disjoint cy…

math.CO2025

Proof of a conjecture on eigenvalues of transposition graph

Cheng Yeaw Ku, Leyou Xu

The transposition graph $C a y (S_{n}, T_{n})$ is the Cayley graph on the symmetric group $S_{n}$ generated by the set $T_{n}$ of all transpositions. In this paper, we show that each integer i…

math.CO2014

Cayley Graph on Symmetric Group Generated by Elements Fixing $k$ Points

Kok Bin Wong, Terry Lau, Cheng Yeaw Ku

Let $S_{n}$ be the symmetric group on $[n] = {1, \dots, n}$ . The $k$ -point fixing graph $F (n, k)$ is defined to be the graph with vertex set $S_{n}$ a…

math.CO2014

An Erd{\H o}s-Ko-Rado theorem for permutations with fixed number of cycles

Cheng Yeaw Ku, Kok Bin Wong

Let $S_{n}$ denote the set of permutations of $[n] = {1, 2, \dots, n}$ . For a positive integer $k$ , define $S_{n, k}$ to be the set of all permutations of $[n]$ with exactly $k$ disjo…

math.CO2013

A generalization of the extremal function of the Davenport-Schinzel sequences

Kok Bin Wong, Cheng Yeaw Ku

Let $[n] = {1, \dots, n}$ . A sequence $u = a_{1} a_{2} \dots a_{l}$ over $[n]$ is called $k$ -sparse if $a_{i} = a_{j}$ , $i > j$ implies $i - j \geq k$ . In other words, every consecutive subsequenc…