Research interests

My research is situated on the interface of functional analysis and analytic group theory. My main research interests are:

• Rigidity properties for group actions
• Banach space expansion and large-scale geometry of infinite graphs
• Operator algebras constructed from groups

Publications

• Dynamical propagation and Roe algebras of warped spaces (with Federico Vigolo and Jeroen Winkel),
  preprint (2023), arXiv version.
  
  
• Unitary L^p+-representations of almost automorphism groups (with Antje Dabeler, Emilie Mai Elkiær and Maria Gerasimova),
  to appear in C.R. Math., arXiv version.
  
  
• Actions of higher rank groups on uniformly convex Banach spaces (with Mikael de la Salle),
  preprint, arXiv version.
  
  
• Spectral gap and origami expanders (with Goulnara Arzhantseva, Dawid Kielak and Damian Sawicki),
  to appear in Comment. Math. Helv., arXiv version.
  
  
• Weak*-continuity of invariant means on spaces of matrix coefficients (with Safoura Zadeh),
  J. Math. Anal. Appl. 506 (2022), Paper No. 125669, published version, arXiv version.
  
  
• Group C*-algebras of locally compact groups acting on trees (with Dennis Heinig and Timo Siebenand),
  Int. Math. Res. Not., rnad259, published version, arXiv version.
  
  
• Exotic group C*-algebras of simple Lie groups with real rank one (with Timo Siebenand),
  Ann. Inst. Fourier (Grenoble) 71 (2021), 2117-2136, published version, arXiv version.
  
  
• The Fourier algebra of a rigid C*-tensor category (with Yuki Arano and Jonas Wahl),
  Publ. Res. Inst. Math. Sci. 54 (2018), 393-410, published version, arXiv version.
  
  
• Superexpanders from group actions on compact manifolds (with Federico Vigolo),
  Geom. Dedicata 200 (2019), 287-302, published version, arXiv version.
  
  
• Banach space actions and L2-spectral gap (with Mikael de la Salle),
  Anal. PDE 14 (2021), 45-76, published version, arXiv version.
  
  
• Howe-Moore type theorems for quantum groups and rigid C*-tensor categories (with Yuki Arano and Jonas Wahl),
  Compos. Math. 154 (2018), 328-341, published version, arXiv version.
  
  
• On strong property (T) and fixed point properties for Lie groups (with Masato Mimura and Mikael de la Salle),
  Ann. Inst. Fourier (Grenoble) 66 (2016), 1859-1893, published version, arXiv version.
  
  
• A complete characterization of connected Lie groups with the Approximation Property (with Uffe Haagerup and Søren Knudby),
  Ann. Sci. Éc. Norm. Supér. 49 (2016), 927-946, published version, arXiv version.
  
  
• Approximation properties for noncommutative Lp-spaces of high rank lattices and nonembeddability of expanders (with Mikael de la Salle),
  J. Reine Angew. Math. 737 (2018), 49-69, published version, arXiv version.
  
  
• Strong property (T) for higher rank simple Lie groups (with Mikael de la Salle),
  Proc. London Math. Soc. 111 (2015), 936-966, published version, arXiv version.
  
  
• Simple Lie groups without the Approximation Property II (with Uffe Haagerup),
  Trans. Amer. Math. Soc. 368 (2016), 3777-3809, published version, arXiv version.
  
  
• On the Grothendieck Theorem for jointly completely bounded bilinear forms,
  T.M. Carlsen et al. (eds.), Operator Algebra and Dynamics, Springer Proc. Math. Stat., Vol. 58, pp. 211-221, Springer, Heidelberg, 2013, published version, arXiv version.
  
  
• Approximation properties for noncommutative Lp-spaces associated with lattices in Lie groups,
  J. Funct. Anal. 264 (2013), 2300-2322, published version, arXiv version.
  
  
• Simple Lie groups without the Approximation Property (with Uffe Haagerup),
  Duke Math. J. 162 (2013), 925-964, published version, arXiv version.
  
  
• On the Regularization of the Kepler Problem (with Gert Heckman),
  J. Symplectic Geom. 10 (2012), 463-473, published version, arXiv version.

Theses

• Approximation properties for Lie groups and noncommutative Lp-spaces,
  PhD thesis in Mathematics (2013), University of Copenhagen (Denmark),
  Advisors: Magdalena Musat and Uffe Haagerup.
  
  
• Regularization and Quantization of the Kepler Problem,
  Master thesis in Mathematics (2010), Radboud University Nijmegen (The Netherlands),
  Supervisor: Gert Heckman.

Other writings

• Origami expanders (joint work with Goulnara Arzhantseva, Dawid Kielak and Damian Sawicki),
  Geometric Structures in Group Theory, Oberwolfach Rep.
  
  
• Group C*-algebras of locally compact groups acting on trees (joint work with Dennis Heinig and Timo Siebenand),
  Geometric Structures in Group Theory, Oberwolfach Rep. 17 (2020), 884-886.
  
  
• Mini-Workshop: Superexpanders and Their Coarse Geometry,
  Abstracts from the mini-workshop held April 15 - 21, 2018, organized by A. Khukhro, T. de Laat and M. de la Salle,
  Oberwolfach Rep. 15 (2018), 1117-1160.
  
  
• Howe-Moore type theorems for quantum groups and rigid C*-tensor categories (joint work with Yuki Arano and Jonas Wahl),
  C*-Algebras, Oberwolfach Rep. 13 (2016), 2322-2324.
  
  
• A complete characterization of connected Lie groups with the Approximation Property (joint work with Uffe Haagerup and Søren Knudby),
  Noncommutative Geometry, Oberwolfach Rep. 12 (2015), 1643-1645.