Boij-Söderberg Decompositions of Lex-segment Ideals

Abstract: Boij-S\"oderberg theory describes the scalar multiples of Betti diagrams of graded modules over a polynomial ring as a linear combination of pure diagrams with positive coefficients. There are a few results that describe Boij-S\"oderberg decompositions explicitly. In this paper, we focus on the Betti diagrams of lex-segment ideals and describe the Boij-S\"oderberg decomposition of a lex-segment ideal in terms of Boij-S\"oderberg decompositions of some other related lex-segment ideals.