t. We study the k-core of a random (multi)graph on n vertices with a given degree sequence. We let n → ∞. Then, under some
regularity conditions on the degree sequences, we give conditions on
the asymptotic shape of the degree sequence that imply that with high
probability the k-core is empty, and other conditions that imply that
with high probability the k-core is non-empty and the sizes of its vertex
and edge sets satisfy a law of large numbers; under suitable assumptions
these are the only two possibilities. In particular, we recover the result
by Pittel, Spencer and Wormald [19] on the existence and size of a k-core
in G(n, p) and G(n, m), see also Molloy [17] and Cooper [3].
Our method is based on the properties of empirical distributions of
independent random variables, and leads to simple proofs.