Smooth scheme morphisms: a fresh view
arXiv:1602.06569
Abstract
Relations between some kinds of formal and standard smoothness, for morphisms of schemes, are clarified in surprisingly simple and direct ways, bypassing much of the customarily employed machinery. Even the deep local-to-global property of formal smoothness has a fairly elementary proof, under mild additional hypotheses.
v3: New title. Introduction largely rewritten, other minor alterations. 11 pages