Segre powers of posets preserve EL-shellability

Yifei Li, Sheila Sundaram

For a bounded and graded poset $P$, we show that if $P$ is EL-shellable, then so is its $t$-fold Segre power $P^{(t)}=P\circ \cdots \circ P$ ($t$ factors), as defined by Björner an…