2023/08/03 by Johnson, Will, Yao, Ningyuan · 1 citation
#03C60 #FOS: Mathematics #Logic (math.LO)
paper · doi:10.48550/arxiv.2308.01527
We generalize two of our previous results on abelian definable groups in p-adically closed fields to the non-abelian case. First, we show that if G is a definable group that is not definably compact, then G has a one-dimensional definable subgroup which is not definably compact. This is a p-adic analogue of the Peterzil-Steinhorn theorem for o-minimal theories. Second, we show that if G is a group definable over the standard model ℚp, then G0 = G00. As an application, definably amenable groups over ℚp are open subgroups of algebraic groups, up to finite factors. We also prove that G0 = G00 when G is a definable subgroup of a linear algebraic group, over any model.