Fang Duan

collaborators

3 papers

math.CO2026

Some classes of connected signed graphs with girth $g$ and negative inertia index $⌈ \frac{g}{2} ⌉ + 1$

BeiYan Liu, Fang Duan

Let $Γ$ be a signed graph. The number of negative eigenvalues of the adjacency matrix of $Γ$ is called the negative inertia index of $Γ$ , which is denoted by $i_{-} (Γ)$ . The length o…

math.SP2025

Inertia indices of signed graphs with given cyclomatic number and given number of pendant vertices

Jie Pu, Fang Duan

Let $Γ = (G, σ)$ be a signed graph of order $n$ with underlying graph $G$ and a sign function $σ : E (G) \to {+, -}$ . Denoted by $i_{+} (Γ)$ , $θ (Γ)$ and $p (Γ)$ the positive inert…

math.SP2025

Connected signed graphs with given inertia indices and given girth

Beiyan Liu, Fang Duan

Suppose that $Γ = (G, σ)$ is a connected signed graph with at least one cycle. The number of positive, negative and zero eigenvalues of the adjacency matrix of $Γ$ are called positiv…

Some classes of connected signed graphs with girth g and negative inertia index ⌈2g​⌉+1

Inertia indices of signed graphs with given cyclomatic number and given number of pendant vertices

Connected signed graphs with given inertia indices and given girth

Some classes of connected signed graphs with girth $g$ and negative inertia index $⌈ \frac{g}{2} ⌉ + 1$