3 papers
math.GR2026
Semisimple algebraic groups over real closed fields
Raphael Appenzeller
We give a self-contained introduction to linear algebraic and semialgebraic groups over real closed fields, and we generalize several key results about semisimple Lie groups to alg…
math.GR2026
Generalized affine buildings for semisimple algebraic groups over real closed fields
Raphael Appenzeller
We use real algebraic geometry to construct an affine -building associated to the -points of a semisimple algebraic group, where is a valued real cl…
math.MG2025
Flat subsets of Euclidean buildings
Raphael Appenzeller, Auguste Hébert, Alexander Lytchak
We prove that any convex flat subset in a complete Euclidean building is contained in an apartment of the maximal system of apartments.