A Kronecker coefficient is the multiplicity of the complex Specht module
in
for the symmetric
group
, where all three partitions
have the same size
. Equivalently, writing
for its group character,
It is a nonnegative integer and is symmetric in the three partitions. For example, for
contains the trivial
representation, the sign representation,
and the two-dimensional irreducible representation,
each once. Saxl's conjecture requires positivity
of these coefficients when the first two partitions
are the same staircase.