Lin-Lu-Yau curvature is a notion of curvature on a finite connected simple graph with at least two vertices. For , let
give mass
to vertex
and distribute the remaining mass equally among its neighbors.
For distinct vertices
and
, define
where
is graph distance and
is the Wasserstein distance
for that distance. The Lin-Lu-Yau curvature is
Zhou and Zhang (2026) proved that a graph with graph diameter at least 3 has edge connectivity , where
is its minimum vertex degree and
is the minimum Lin-Lu-Yau curvature over edges.
For graph diameter 2, they proved
.