Let be a simplicial complex. We study the expansions of mainly to see how the algebraic and combinatorial properties of and its expansions are related to each other. It is shown that is Cohen–Macaulay, sequentially Cohen–Macaulay, Buchsbaum or k-decomposable, if and only if an arbitrary expansion of has the same property. Moreover, some homological invariants like the regularity and the projective dimension of the Stanley– Reisner ideals of and those of their expansions are compared. Intr
