Q. Ji

activity

20092026

collaborators

5 papers

math.CO2026

A linear algebraic proof of the Laplacian spread conjecture

Bocheng Li, Qingzhong Ji

For a graph $G,$ let $α (G)$ denote its second smallest Laplacian eigenvalue. The Laplacian Spread Conjecture is that $α (G) + α (G) \geq 1,$ where $G$ is the comp…

math.CO2023

The graphs which are cospectral with the generalized pineapple graph

Borchen Li, Qingzhong Ji

Let $p, k, q$ be positive integers with $p - 2 ⩾ k$ and let $K_{p, k}^{q}$ be the generalized pineapple graph which is obtained by joining independent set of $q$ vertices with…

math.NT2013

Lehmer's totient problem over $F_{q} [x]$

Qingzhong Ji, Hourong Qin

In this paper, we consider the function field analogue of the Lehmer's totient problem. Let $p (x) \in F_{q} [x]$ and $φ (q, p (x))$ be the Euler's totient function of $p (x)$ over…

math.NT2011

Higher $K$ -Groups of Smooth Projective Curves Over Finite Fields

Qingzhong Ji, Hourong Qin

Let $X$ be a smooth projective curve over a finite field $F$ with $q$ elements. For $m \geq 1,$ let $X_{m}$ be the curve $X$ over the finite field $F_{m}$ , the $m$ -th…

math.NT2009

On the periodicity of some Farhi arithmetical functions

Qing-Zhong Ji, Chun-Gang Ji

Let $k \in N$ . Let $f (x) \in Z [x]$ be any polynomial such that $f (x)$ and $f (x + 1) f (x + 2) ... f (x + k)$ are coprime in $Q [x]$ . We call $$g_{k,f}(n):=\frac{|f(n)f(n+…

A linear algebraic proof of the Laplacian spread conjecture

The graphs which are cospectral with the generalized pineapple graph

Lehmer's totient problem over Fq​[x]

Higher K-Groups of Smooth Projective Curves Over Finite Fields

On the periodicity of some Farhi arithmetical functions

Lehmer's totient problem over $F_{q} [x]$

Higher $K$ -Groups of Smooth Projective Curves Over Finite Fields