A Motivic Snaith Decomposition

Abstract

The filtration $\operatorname{BGL}_{0}\subset\dots\subset\operatorname{BGL}_{n-1}\subset\operatorname{BGL}_{n}$ is split by motivic Becker-Gottlieb transfers in the motivic stable homotopy category over any scheme. This recovers results by Snaith on the splitting of $\operatorname{BGL}_{n}(\mathbb{C})$ in classical stable homotopy theory by passing to complex realizations. On the way, we extend motivic homotopy theory to smooth ind-schemes as bases and show how to construct the necessary fragment of the six operations and duality for this extension.