Rectangular symmetries for coefficients of symmetric functions
  We show that some of the main structural constants for symmetric functions (Littlewood-Richardson coefficients, Kronecker coefficients, plethysm coefficients, and the Kostka--Foulkes polynomials) share symmetries related to the operations of taking complements with respect to rectangles and adding rectangles. 
Emmanuel Briand, Rosa Orellana and Mercedes Rosas
math.CO