Homepages

(hier geht es zur ggf. vollständigeren Homepage im alten Layout)
(this way to the possibly more complete Homepage in the old layout)

Publications

• Tree amalgamations and quasi-isometries
  Journal of Combinatorial Theory (Series B) 173 (2025), 83-101
  
  
• Quasi-transitive K_∞-minor free graphs
  European Journal of Combinatorics 124 (2025), Paper No. 104056
  
  
• with A. Georgakopoulos
  A full Halin grid theorem
  Discrete & Computational Geometry (2024)
  
  
• Minor exclusion in quasi-transitive graphs
  Discrete Mathematics 347 (2024), 113738
  
  
• with A. Georgakopoulos
  The planar Cayley graphs are effectively enumerable II
  European Journal of Combinatorics 110 (2023), Paper No. 103668
  
  
• with F. Lehner, B. Miraftab & T. Rühmann
  A Stallings type theorem for quasi-transitive graphs
  Journal of Combinatorial Theory (Series B) 157 (2022), 40-69
  
  
• with J. Carmesin & B. Miraftab
  Canonical trees of tree-decompositions
  Journal of Combinatorial Theory (Series B) 152 (2022), 1-26
  
  
• with A. Georgakopoulos
  The planar Cayley graphs are effectively enumerable I: consistently planar graphs
  Combinatorica 39 (2019), 993-1019
  
  
• Self-embeddings of trees
  Discrete Mathematics 342 (2019), 111586
  
  
• Planar transitive graphs
  Electronic Journal of Combinatorics 25 (2018), Paper 4.8
  
  
• Accessibility in transitive graphs
  Combinatorica 38 (2018), 847-859
  
  
• On the tree-likeness of hyperbolic spaces
  Math. Proc. Cambridge Philos. Soc. 164 (2018), 345-361
  
  
• The classification of finite and locally finite connected-homogeneous digraphs
  Combinatorica 37 (2017), 183-222
  
  
• with D. Weißauer
  Bounding connected tree-width
  SIAM Journal on Discrete Mathematics 30 (2016), 1391-1400
  
  
• Groups acting on metric spaces: fixed points and free subgroups
  Abhandlungen des Mathematischen Seminars der Universität Hamburg 87 (Special Issue: Rudolf Halin) (2017), 245-263
  
  
• with F. Lehner & J. Pott
  Extending cycles locally to Hamilton cycles
  Electronic Journal of Combinatorics 23 (2016), Paper 1.49
  
  
• with J. Carmesin, R. Diestel & F. Hundertmark
  Canonical tree-decompositions of finite graphs II. Essential parts
  Journal of Combinatorial Theory (Series B) 118 (2016), 268-283
  
  
• with J. Carmesin, R. Diestel & F. Hundertmark
  Canonical tree-decompositions of finite graphs I. Existence and algorithms
  Journal of Combinatorial Theory (Series B) 116 (2016), 1-24
  
  
• Spanning trees in hyperbolic graphs
  Combinatorica 36 (2016), 313-332
  
  
• Generating the cycle space of planar graphs
  Electronic Journal of Combinatorics 22 (2015), Paper 2.34
  
  
• with J. Carmesin, R. Diestel & F. Hundertmark
  k-Blocks: a connectivity invariant for graphs
  SIAM Journal on Discrete Mathematics 28 (2014), 1876-1891
  extended version
  
  
• Homogeneous 2-partite digraphs
  Discrete Mathematics 327 (2014), 36-39
  
  
• with F. Hundertmark
  The classification of connected-homogeneous digraphs with more than one end
  Transactions of the AMS 365 (2013), 531-553
  
  
• with J. Pott
  Transitivity conditions in infinite graphs
  Combinatorica 32 (2012), 649-688
  
  
• with A. Georgakopoulos
  On fixing boundary points of transitive hyperbolic graphs
  Archiv der Mathematik 99 (2012), 91-99
  
  
• End-transitive graphs
  Israel Journal of Mathematics 189 (2012), 437-459
  
  

Preprints

• Countable connected-homogeneous digraphs
  submitted
  
  
• Tree amalgamations and hyperbolic boundaries
  submitted
  
  
• Asymptotic dimension of multi-ended quasi-transitive graphs
  submitted
  
  
• with B. Miraftab
  Two characterisations of accessible quasi-transitive graphs
  submitted
  
  
• Quasi-isometry invariance of hyperbolicity in semimetric spaces, digraphs and semigroups
  submitted
  
  
• A boundary for hyperbolic digraphs and semigroups
  submitted
  
  
• Free submonoids of hyperbolic monoids
  submitted
  
  
• with T. Abrishami, L. Esperet, U. Giocanti, P. Knappe, R.G. Möller
  Periodic colorings and orientations in infinite graphs
  submitted
  
  
• with K. Heuer
  An end degree for digraphs
  submitted
  
  
• with K. Heuer
  Infinite grids in digraphs
  submitted
  
  
• with S. Albrechtsen
  Asymptotic half-grid and full-grid minors
  submitted
  
  

Theses

• Connected-homogeneous digraphs
  Habilitationsschrift, University of Hamburg, Department of Mathematics, September 2014
  
  
• Infinite graphs with a treelike structure
  PhD Thesis, University of Hamburg, Department of Mathematics, June 2011
  
  
• Über die lokale Struktur endlicher Gruppen lokaler Charakteristik p vom Rang 2
  Diplomarbeit, Christian-Albrechts-Universität zu Kiel, Mathematisches Seminar, October 2007