The center conjecture for convex subcomplexes of spherical buildings

About 17 years old · traced to

Let Δ\Delta be a (weak) spherical building and let KK be a convex chamber subcomplex of Δ\Delta. A chamber DD is opposite to a chamber CC if they are opposite in the spherical building.

Center conjecture. At least one of the following two possibilities holds:

  1. For each chamber CC in KK there is a chamber DD in KK opposite to CC.
  2. The group of automorphisms of Δ\Delta stabilizing KK stabilizes a non-trivial simplex of KK.

This conjecture is a fixed-point statement for automorphism groups stabilizing convex subcomplexes of spherical buildings. The supplied text identifies it as the center conjecture but gives no evidence of its resolution.

Equivalent formulations 1Other wordings

Other statements of this same problem, merged from separate entries. Each is equivalent to the statement above — proving any one settles them all.

  1. The Center Conjecture for convex subcomplexes of spherical buildings

    Let BB be a spherical building and let K⊆BK\subseteq B be a convex subcomplex. Center Conjecture. Then KK is a subbuilding or the action

    StabAut(B)(K)↷KStab_{Aut(B)}(K)\curvearrowright K

    of the automorphisms of BB preserving KK has a fixed point. This is a geometric version of Tits' Center Conjecture. The claim is posed here for convex subcomplexes of spherical buildings; the corresponding fixed-point question is known positively in dimensions at most 22, while the higher-dimensional cases under consideration remain open.

    source: B. Leeb and C. Ramos-Cuevas, “The Center Conjecture for spherical buildings of types F4 and E6”, arXiv:0905.0839 (2011).

References

Primary source

Koen Struyve, “(Non-)completeness of R-buildings and fixed point theorems”, arXiv:0909.3202 (2009).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.