Motivic Cell Structures for Spherical Varieties

In this note, we give a general method to obtain unstable motivic cell structures, following Wendt’s application of the Bialynicki-Birula algebraic Morse theory. We then apply the method to spherical varieties, with special attention to the case of rank 1, to obtain unstable motivic cell structures after a finite number of ${\mathbb{P}}^1$-suspensions. This work is a partial derivative of the first two chapters of the author’s 2016 PhD thesis.