Foliations on the space of $p$-divisible groups were studied by Oort in 2004. In his theory, special leaves called central streams play an important role. In this paper, we give a complete classification of the boundary components of the central streams for an arbitrary Newton polygon in the unpolarized case. Hopefully this classification would help us to know the boundaries of other leaves and more detailed structure of the boundaries of central streams.
This research is partially supported by Grant-in-Aid
for JSPS Fellows.
I thank the referee for careful reading and helpful comments. This paper is written when the author was a Ph.D. student. I thank the supervisor Professor Harashita for the constant support from the early stage of this paper.
"On the Boundary Components of Central Streams." Taiwanese J. Math. Advance Publication 1 - 35, 2021. https://doi.org/10.11650/tjm/210304