Research interests

  • Quantum groups
  • Operator algebras
  • Operator spaces and their approximation properties
  • Non-commutative Lp-spaces
  • Harmonic analysis on non-commutative spaces

Papers and preprints

Any comment, suggestion or question is more than welcome. "Final version" indicates that the ArXiv-version agrees with the version that was sent for the publication process.

  • "On the best constants of Schur multipliers of second order divided difference functions".
    With Jesse Reimann.

Papers (in press)
  • "Classification of right-angled Coxeter groups with a strongly solid von Neumann algebra".
    With Matthijs Borst.
    Accepted for Journal de Mathématiques Pures et Appliquées.

  • "Local and multilinear noncommutative de Leeuw theorems".
    with Bas Janssens, Amudhan Krishnaswamy-Usha and Lukas Miaskiwskyi.
    Math. Ann. 388 (2024), no. 4, 4251-4305.
    preprint (final version).

  • "Bimodule coefficients, Riesz transforms on Coxeter groups and strong solidity".
    with Matthijs Borst and Mateusz Wasilewski.
    Groups Geom. Dyn. 18 (2024), no. 2, 501–549.
    preprint (final version).

  • "A Sobolev estimate for radial Lp-multipliers on a class of semi-simple Lie groups".
    Trans. Amer. Math. Soc. 376 (2023), no. 12, 8919–8938.
    preprint (final version).

  • "On the isomorphism class of q-Gaussian W*-algebras for infinite variables".
    preprint (final version).
    C. R. Math. Acad. Sci. Paris 361 (2023), 1711–1716.

  • "Multilinear transference of Fourier and Schur multipliers acting on non-commutative Lp-spaces".
    with Amudhan Krishnaswamy-Usha and Gerrit Vos.
    Canad. J. Math. 75 (2023), no. 6, 1986–2006.

  • "Overcompleteness of coherent frames for unimodular amenable groups".
    with Jordy Timo van Velthoven.
    Ark. Mat. 61 (2023), no. 2, 277-299.

  • "Relative Haagerup property for arbitrary von Neumann algebras".
    with Mario Klisse, Adam Skalski, Gerrit Vos and Mateusz Wasilewski.
    Adv. Math. 421 (2023), Paper No. 109017.

  • "On the isomorphism class of q-Gaussian C*-algebras for infinite variables".
    with Matthijs Borst, Mario Klisse and Mateusz Wasilewski.
    Proc. Amer. Math. Soc. 151 (2023), no. 2, 737–744.
    preprint (final version).

  • "Riesz transforms on compact quantum groups and strong solidity".
    J. Inst. Math. Jussieu 21 (2022), no. 6, 2135–2171
    preprint (final version).

  • "Density conditions with stabilizers for lattice orbits of Bergman kernels on bounded symmetric domains".
    with Jordy Timo van Velthoven.
    Math. Z. 302, 609–628 (2022).
    preprint (final version).

  • "BMO spaces of sigma-finite von Neumann algebras and Fourier-Schur multipliers on quantum SU(2)".
    with Gerrit Vos.
    Studia Math. 262 (2022), no. 1, 45–91.
    preprint (final version).

  • "Weak (1,1) estimates for multiple operator integrals and generalized absolute value functions".
    with Fedor Sukochev and Dmitriy Zanin.
    Israel J. Math. 244 (2021), no. 1, 245–271.
    preprint (final version).

  • "L2-cohomology, derivations and quantum Markov semi-groups on q-Gaussian algebras".
    with Yusuke Isono and Mateusz Wasilewski.
    Int. Math. Res. Not. IMRN 2021, no. 9, 6405–6441.
    preprint (final version).

  • "Gradient forms and strong solidity of free quantum groups".
    Math. Ann. 379 (2021), no. 1-2, 271–324.
    preprint (final version).

  • "Graph product Khintchine inequalities and Hecke C*-algebras: Haagerup inequalities, (non)simplicity, nuclearity and exactness".
    with Mario Klisse and Nadia Larsen.
    J. Funct. Anal. 280 (2021), no. 1, 108795.
    preprint (final version).

  • "Absence of Cartan subalgebras for right-angled Hecke von Neumann algebras".
    Anal. PDE 13 (2020), no. 1, 1--28.
    preprint (final version), erratum.

  • "BMO-estimates for non-commtutative vector valued Lipschitz functions".
    with Marius Junge, Fedor Sukochev, Dima Zanin.
    J. Funct. Anal. 278 (2020), no. 3, 108317.
    preprint (final version).

  • "On MASAs in q-deformed von Neumann algebras".
    with Adam Skalski and Mateusz Wasilewski.
    Pacific J. Math. 302 (2019), no. 1, 1--21.
    preprint (final version).

  • "Weak type commutator and Lipschitz estimates: resolution of the Nazarov-Peller conjecture".
    with Denis Potapov, Fedor Sukochev and Dmitriy Zanin.
    Amer. J. Math. 141 (2019), no. 3, 593–610.
    preprint (final version).

  • "On the complete bounds of Lp-Schur multipliers".
    with Guillermo Wildschut.
    Arch. Math. (Basel) 113 (2019), no. 2, 189–200.
    preprint (final version).

  • "On C*-completions of discrete quantum group rings".
    with Adam Skalski.
    Bull. London Math. Soc. 51 (2019), no. 4, 691-704.
    preprint (final version).

  • "Harmonic analysis and BMO-spaces of free Araki-Woods factors".
    Studia Math. 246 (2019), no. 1, 71–107.
    preprint (final version).

  • "Weak type operator Lipschitz and commutator estimates for commuting tuples".
    with Fedor Sukochev and Dmitriy Zanin.
    Ann. Inst. Fourier (Grenoble) 68 (2018), no. 4, 1643–1669.
    preprint (final version).

  • "Graph products of operator algebras".
    with Pierre Fima.
    J. Noncommut. Geom. 11 (2017), no. 1, 367-411.
    preprint (final version).

  • "Connes embeddability of graph products".
    Infin. Dimens. Anal. Quantum Probab. Relat. Top. 19 (2016), no. 1, 1650004, 13 pp.
    preprint (final version).

  • "Operator biflatness of the L1-algebras of compact quantum groups".
    with Hun Hee Lee and Eric Ricard.
    J. Reine Angew. Math. 700 (2015), 235-244.
    preprint (final version).

  • "Schur and Fourier multipliers of an amenable group acting on non-commutative Lp-spaces".
    with Mikael de la Salle.
    Trans. Amer. Math. Soc. 367 (2015), no. 10, 6997-7013.
    preprint (final version).

  • "The Haagerup approximation property for von Neumann algebras via quantum Markov semigroups and Dirichlet forms".
    with Adam Skalski.
    Comm. Math. Phys. 336 (2015), no. 3, 1637-1664.
    preprint (final version).

  • "Noncommutative de Leeuw theorems".
    with Javier Parcet, Mathilde Perrin, Eric Ricard.
    Forum of Mathematics - Sigma 3 (2015), e21.
    preprint (not final but journal is open access).

  • "The Haagerup property for arbitrary von Neumann algebras".
    with Adam Skalski.
    Int. Math. Res. Not. IMRN 2015, no. 19, 9857-9887.
    preprint (final version).

  • "Weak type estimates for the absolute value mapping".
    with Denis Potapov, Fedor Sukochev and Dima Zanin.
    J. Operator Theory 73 (2015), no. 2, 361-384.
    preprint (final version).

  • "The best constants for operator Lipschitz functions on Schatten classes".
    with Stephen Montgomery-Smith, Denis Potapov and Fedor Sukochev.
    J. Funct. Anal. 267 (2014), no. 10, 3557-3579.
    preprint (final version).

  • "Weak amenability of locally compact quantum groups and approximation properties of extended quantum SU(1,1)".
    Comm. Math. Phys. 331 (2014), no. 3, 1041-1069.
    preprint (final version).

  • "Generalisations of the Haagerup approximation property to arbitrary von Neumann algebras".
    with Rui Okayasu, Adam Skalski, Reiji Tomatsu.
    C. R. Acad. Sci. Paris, Ser. I 352 (2014) 507-510
    preprint (final version).

  • "The Walsh basis in the Lp-spaces of hyperfinite III_\lambda factors, 0 < \lambda <=1".
    with Denis Potapov and Fedor Sukochev.
    J. Math. Anal. Appl. 408 (2013), 154-164
    preprint (final version), journal.

  • "The L^p-Fourier transform on locally compact quantum groups".
    J. Operator Theory 69 (2013), 161-193
    preprint (final version), journal

  • "Spherical Fourier transforms on locally compact quantum Gelfand pairs".
    SIGMA 7 (2011), 087, 39 pages.
    paper (final version), journal.

  • "Modular properties of matrix coefficients of corepresentations of a locally compact quantum group".
    Together with Erik Koelink.
    J. Lie Theory 21 (2011), no. 4, 905-928.
    preprint (final version), journal.

  • "Intuitionistic quantum logic of an n-level system".
    Together with Chris Heunen, Klaas Landsman and Bas Spitters.
    Foundations of Physics 39 (2009), No. 7, 731-759.
    preprint (final version), journal.

  • "Profcast" interview with Dave Boomkens and Marieke Kootte (in Dutch), 2021.
    See spotify or (soon) the webpage.
    My thanks to Klaas Landsman and Erik Koelink for their contributions!

  • "Weight theory for ultraproducts".
    Preprint contains a mistake and the main result should be extended to non-semifinite weights. I am happy to discuss with anyone who has ideas.

  • "Quantum Symmetry". 2021
    Oberwolfach Snapshot - popular article describing the fundamental idea of quantum groups.

  • "Mini-workshop: operator algebraic quantum groups". 2020.
    with Michael Brannan, Moritz Weber, Anna Wysoczanska-Kula.
    Oberwolfach Rep. 16 (2020), no. 4, 2821–2867.

  • "On the endpoints of De Leeuw restriction theorems". 2018.
    Chapter in Festschrift on the occassion of Ben de Pagter's 65th anniversary.

  • "Locally compact quantum groups". Lecture notes, Bedlewo 2015.
    Banach Center Publications 111 (2017), 153-184.

  • "Noncommutative De Leeuw theorems". Noncommutative geometry. Oberwolfach Reports 2 (2015), 1631-1700.

  • "Hecke von Neumann algebras, operator spaces and absence of Cartan subalgebras". Noncommutative geometry and operator spaces in interaction. Oberwolfach Reports, 2016.

  • "Gradient forms and strong solidity of free quantum groups". Interactions between Operator Space Theory and Quantum Probability with Applications to Quantum Information. Oberwolfach Reports, 2018.

  • "Quantum groups and special functions". Winter school in Bizerte, Tunisia, 2010.
    Prepared together with Erik Koelink.

  • "Non-commutative integration on locally compact quantum groups" (PhD Thesis 2012).
    Adviser: Erik Koelink
    Download: Thesis.

  • "Gelfand spectra of C*-algebras in topos theory" (MSc. Thesis 2008).
    Under supervision of Klaas Landsman.
    Awarded with the GQT MSc. thesis prize.