Research
Research interests of the group include
 Geometry: Tits buildings, symmetric spaces, nonpositive curvature, metric geometry, isoparametric submanifolds.
 Groups: Geometric group theory, Lie groups, transformation groups, isometric actions, algebraic groups, classical groups.
 Topology: Geometric topology, homogeneous spaces, group cohomology.
Postdocs
 Dr. Rupert McCallum
 Dr. Petra Schwer
 Dr. Daniel Skodlerack
 Dr. Stefan Witzel
Current PhD Projects
 Antoine Beljean
 Olga Varghese
Research Grants and Funding
 SFB 878 Project B4 Reductive groups and combinatorial structures (Kramer)
 DFG Project Exceptional groups and geometrical structures (Kramer and Weiss)
 DFG Project Hadamard spaces: rigidity and recognition theorems (Schwer)
 Promotionsstipendien: DAAD, Studienstiftung des Deutschen Volkes, TelekomStiftung
Current Research Projects
 Structure of nondiscrete affine buildings (Kramer, Schwer, Beljean)
 Cubical complexes and systolic geometry (Schwer)
 Embeddings between BruhatTits Buildings (Skodlerack)
 Lattices and geometric group theory (Witzel)
 Buildings and topological groups (McCallum, Kramer)
 Actions of Aut(F_{n}) (Varghese)
 Buildings and group cohomology (Kramer)
 Buildings and exceptional groups (Kramer joint with R. Weiss)
 Classification of isoparametric hypersurfaces (Kramer joint with S. Stolz)
Preprints from our group

M. Fluch, S. Witzel,
Brown's criterion in Bredon homology.
Preprint. 
S. Witzel,
Abels's groups revisited.
Preprint. 
M. Fluch, M. Schwandt, S. Witzel, M.C.B. Zaremsky,
The BrinThompson groups sV are of type F_{∞}.
Preprint.  O. Varghese,
Fixed points for actions of Aut(F_{n}) on CAT(0) spaces.
Submitted.  D. Skodlerack,
On intertwining implies conjugacy for classical groups.
Preprint.  J. Essert,
On Wagoner complexes.
Submitted.  F. Magata,
An integration formula for polar actions.
Preprint.  L. Kramer,
Notes on completely reducible subcomplexes of spherical buildings.
Lecture notes from April 2008.
Publications from our group since 2010
 D. Skodlerack,
Field embeddinngs which are conjugate under a padic classical group.
Manuscripta Math. 144 (2014), no. 12, 277–301.  D. Skodlerack,
Embeddings of local fields in simple algebras and simplicial structures.
Publ. Mat. 58 (2014), no. 2, 499–516.  L. Kramer, R. Weiss,
Coarse equivalences of Euclidean buildings.
Adv. Math. 253 (2014), no 1, 149.  J. Essert,
A geometric construction of panelregular lattices in buildings of types
\(\tilde A_2\) and \(\tilde C_2\).
Algebr. Geom. Topol. 13 (2013), no. 3, 1531–1578. 
K.H. Hofmann, L. Kramer,
Transitive actions of locally compact groups on locally contractible spaces.
To appear in J. Reine Angew. Mathematik.  J. Essert,
Homological stability of classical groups.
Israel J. Math. 198 (2013), no. 1, 169–204.  R. McCallum,
A localtoglobal result for topological spherical buildings.
Adv. Geom. 13 (2013), no. 3, 435–448.  K.U. Bux, R. Köhl, S. Witzel,
Higher finiteness properties of reductive arithmetic groups in positive characteristic: the Rank Theorem.
Ann. of Math. (2) 177 (2013), no. 1, 311–366.  D. Skodlerack,
The centralizer of a classical group and Bruhat Tits buildings.
Ann. Inst. Fourier (Grenoble) 63 (2013), no. 2, 515–546.  T. Grundhofer, L. Kramer, H. Van Maldeghem, R. M. Weiss,
Compact totally disconnected Moufang buildings.
Tohoku Math. Journal 64 (2012) no 3.  R. Köhl, S. Witzel,
The sphericity of the Phan geometries of type B_{n} and C_{n} and the Phantype theorem of type F_{4}.
To appear in Transactions AMS.  P. Schwer, K. Struyve,
Λbuildings and base change functors.
Geom. Dedicata, 157 (2012) 291  317.  L. Kramer,
Metric properties of euclidean buildings.
In: Global Differential Geometry, Springer Proceedings in Mathematics, Volume 17 (2012).  L. Kramer,
The topology of a semisimple Lie group is essentially unique.
Adv. Math. 228 (2011), no. 5, 26232633.  L. Kramer,
On the local structure and the homology of CAT(κ) spaces and euclidean buildings.
Advances in Geometry 11 (2011), 347369.  P. Hitzelberger,
Nondiscrete affine buildings and convexity.
Advances in Mathematics, 227 (2011) 210  244.  T. Kurth, R. Gramlich and L. Kramer,
The real quadrangle of type E_{6}.
Advances in Geometry 11 (2011), 347369.  E. BornbergBauer and L. Kramer,
Robustness versus evolvability: a paradigm revisited.
HFSP J. Volume 4, Issue 3, pp. 105108, 2010/06.  F. Magata,
A general Weyltype Integration Formula for Isometric Group Actions.
Transformation Groups 15, no. 1 (2010).  P. Hitzelberger, L. Kramer, R. Weiss,
Nondiscrete Euclidean Buildings for the Ree and Suzuki groups.
Amer. J. Math 132, no. 4 (2010).  L. Kramer and K. Tent,
A Maslov cocycle for unitary groups..
Proc. London Math. Soc. 100, no. 3 (2010), 91115.  P. Hitzelberger,
Kostant convexity for affine buildings.
Forum Mathematicum, vol. 22, no. 5 (2010) 959971.