In a 2013 article, Eike Lau constructed a canonical morphism from the stack of $n$-truncated Barsotti-Tate groups over $F_p$ to the stack of n-truncated displays. He also proved that this morphism is a gerbe banded by a commutative group scheme. This e-print is a step towards an explicit description of this group scheme.PDF: On the Lau group scheme.pdf
