Publications
arXiv  Google Scholar  ORCID  MathSciNet 

[87] 
The Liouville property and random walks on topological groups (joint with Martin Schneider) preprint [arXiv] 

[86] 
Aspects of padic operator algebras (joint with Anton Claußnitzer) in preparation 

[85] 
Approximation of functions by neural networks preprint [arXiv] 

[84] 
On the isometrisability of group actions on pspaces (joint with Maria Gerasimova) preprint [arXiv] 

[83] 
Inapproximability of actions and Kazhdan's property (T) (joint with Gabor Kun) preprint [arXiv] 

[82] 
Universal solvability of group equations (joint with Martin Nitsche) preprint [arXiv] 

[81] 
Short Laws for Finite Groups of Lie Type (joint with Henry Bradford) preprint [arXiv] 

[80] 
Word images in symmetric and unitary groups are dense 

[79] 
Asymptotics of Cheeger constants and unitarisability of groups 

[78] 
Stability and Invariant Random Subgroups 

[77] 
Stability, cohomology vanishing, and nonapproximable groups 

[76] 
On Projections of Free Semialgebraic Sets 

[75] 
A note on the normal subgroup lattice of ultraproducts of finite quasisimple groups 

[74] 
A note on commutators in algebras of unbounded operators (joint with Richard Kadison and Zhe Liu) submitted [pdf  arXiv] 

[73] 
BenjaminiSchramm convergence and pointwise convergence of the spectral measure (joint with Miklos Abert and Balint Virag) preprint (in preliminary form) [pdf] 

[72] 
Equivariant characteristic forms in the Cartan model and Borel equivariant cohomology (joint with Andreas Kübel) submitted [arXiv] 

[71] 
Unitarizability, MaureyNikishin factorization, and polish groups of finite type 

[70] 
Short Laws for Finite Groups and Residual Finiteness Growth (joint with Henry Bradford) Transactions of the AMS 371 (2019), no. 9, 64476462. [DOI arXiv] 

[69] 
Bounded Normal Generation and Invariant Automatic Continuity (joint with Philip Dowerk) Adv. Math. 346 (2019), 124–169. [DOI arXiv] 

[68] 
Operator algebraic approach to inverse and stability theorems for amenable groups (joint with Marcus De Chiffre and Narutaka Ozawa) Mathematika 65 (2019), no. 1, 98–118. [DOI arXiv] 

[67] 
Some geometric properties of metric ultraproducts of finite simple groups (joint with John Wilson) Israel J. Math. 227 (2018), no. 1, 113–129. [DOI arXiv] 

[66] 
Equivariant Differential Cohomology (joint with Andreas Kübel) Trans. Amer. Math. Soc. 370 (2018), no. 11, 8237–8283. [DOI arXiv] 

[65] 
Finitary approximations of groups and their applications Proc. of ICM 2018 [arXiv] 

[64] 
L²Betti numbers of totally disconnected groups and their approximation by Betti numbers of lattices (joint with Henrik Densing Petersen and Roman Sauer) Journal of Topology, 11(1), March 2018, 257282 [DOI arXiv] 

[63] 
On Følner sets in topological groups (joint with Friedrich Martin Schneider) Compositio Mathematica, 154 (7), July 2018 , 13331361 

[62] 
An exotic group as limit of finite special linear groups (joint with Alessandro Carderi) Ann. Inst. Fourier 68 (2018), 257–273. [DOI arXiv] 

[61] 
Some remarks on finitarily approximable groups 

[60] 
Quadratic Modules, C*Algebras, and Free Convexity (joint with Vadim Alekseev and Tim Netzer) Transactions of the AMS (2017) [DOI arXiv] 

[59] 
Bounded normal generation for projective unitary groups of certain infinite operator algebras 

[58] 
Cantor systems and quasiisometry of groups 

[57] 
About the solvability of matrix polynomial equations 

[56] 
Spectrahedral Containment and Operator Systems with FiniteDimensional Realization 

[55] 
About the length of laws for finite groups Israel Journal of Mathematics, 219 (2017), 469–478. [DOI arXiv] 

[54] 
Topological matchings and amenability 

[53] 
New topological methods to solve equations over groups 

[52] 
Measured Group Theory, Abstracts from the Oberwolfach workshop held in August 29 September 03, 2016 (organized jointly with Miklos Abert and Damien Gaboriau) Oberwolfach Reports 13(3) (2016), 2347–2397. [DOI] 

[51] 
C*algebras, Abstracts from the Oberwolfach workshop held in August 21 August 27, 2016 (organized jointly with Mikael Rørdam, Stefaan Vaes and Dan Voiculescu) Oberwolfach Reports 13(3) (2016), 2269–2345. [DOI] 

[50] 
The expected degree of minimal spanning forests Combinatorica 36 (2016), no. 5, 591–600. [DOI arXiv] 

[49] 
Character rigidity for special linear groups (joint with Jesse Peterson) J. Reine Angew. Math. 716 (2016), 207–228. [DOI arXiv] 

[48] 
Jost Bürgi’s Method for Calculating the Sines (joint with Menso Folkerts and Dieter Launert) Historia Math. 43 (2016), no. 2, 133–147. [DOI arXiv] 

[47] 
Invariant Coupling of Determinantal Measures on Sofic Groups (joint with Russell Lyons) Ergodic Theory and Dynamical Systems, 36(2) (2016), 574607. [DOI arXiv] 

[46] 
Divisibility and Laws in Finite Simple Groups (joint with Gady Kozma) Math. Ann. 364(1), (2016), 7995. [DOI arXiv] 

[45] 
On the LévyKhinchin decomposition of generating functionals (joint with Uwe Franz und Malte Gerhold) Communications on Stochastic Analysis, Vol. 9, No. 4 (2015), 529544. [publication arXiv] 

[44] 
A new proof of extreme amenability of the unitary group of the hyperfinite II1 factor (joint with Philip Dowerk) Bull. Belg. Math. Soc. Simon Stevin 22 (2015), no. 5, 837–841. [publication arXiv] 

[43] 
Some remarks on the entropy for algebraic actions of amenable groups (joint with NhanPhu Chung) Trans. Amer. Math. Soc. 367 (2015), no. 12, 8579–8595. [DOI arXiv] 

[42] 
On the length of the shortest nontrivial element in the derived and the lower central series (joint with Abdelrhman Elkasapy) J. Group Theory 18 (2015), no. 5, 793–804. [DOI arXiv] 

[41] 
A note on normal generation and generation of groups Communications in Mathematics 23 (1) (2015) 111. [publication arXiv] 

[40] 
Kazhdan’s Property (T) ia semidefinite optimization (joint with Tim Netzer) Experimental Mathematics 24 (3) (2015) 371374. [DOI arXiv] 

[39] 
Palindromic words in simple groups (joint with Elisabeth Fink) Internat. J. Algebra Comput. 25 (2015), no. 3, 439–444. [DOI arXiv] 

[38] 
A remark about the spectral radius Int. Math. Res. Not. IMRN (2015), no. 10, 2856–2864. [DOI arXiv] 

[37] 
Positivstellensätze for quantum multigraphs (joint with Tim Netzer) J. Algebra 422 (2015), 504–519. [DOI arXiv] 

[36] 
About Gotô’s method showing surjectivity of word maps (joint with Abdelrhman Elkasapy) Indiana Univ. Math. J. 63 No. 5 (2014), 1553–1565. [cite arXiv] 

[35] 
Can you compute the operator norm? (joint with Tobias Fritz and Tim Netzer) Proc. Amer. Math. Soc. 142 (2014), no. 12, 42654276. [DOI arXiv] 

[34] 
Hyperbolic polynomials and generalized Clifford algebras (joint with Tim Netzer) Discrete Comput. Geom. 51 (2014), no. 4, 802–814. [DOI arXiv] 

[33] 
Metric ultraproducts of finite simple groups (joint with John Wilson) C. R. Acad. Sci. Paris, Ser. I 352 (2014), no. 6, 463466. [DOI arXiv] 

[32] 
On the lattice of normal subgroups in ultraproducts of compact simple groups (joint with Abel Stolz) Proc. London Math. Soc. 108 (2014), no. 1, 73–102. [DOI arXiv] 

[31] 
Entropy, Determinants, and L²Torsion (joint with Hanfeng Li) J. Amer. Math. Soc. 27 (2014), no. 1, 239–292. [DOI arXiv] 

[30] 
Group Theory, Measure, and Asymptotic Invariants, Abstracts from the Oberwolfach workshop held in August 1923, 2013 (organized jointly with Miklos Abert and Damien Gaboriau) Oberwolfach Reports 10(3) (2013), 23752422. [DOI] 

[29] 
Determinantal representations and the Hermite matrix (joint with Tim Netzer and Daniel Plaumann) Michigan Math. J. Volume 62, Issue 2 (2013), 407420. [DOI arXiv] 

[28] 
Real Closed Separation Theorems and Applications to Group Algebras (joint with Tim Netzer) Pacific Journal of Mathematics Vol. 263 (2013), no. 2, 435452. [DOI arXiv] 

[27] 
Convergent sequences in discrete groups Canad. Math. Bull. 56 (2013), no. 2, 424433. [DOI arXiv] 

[26] 
Applications of Følner's condition to quantum groups (joint with David Kyed) J. Noncommut. Geom. 7 (2013), no. 2, 547–561. [DOI arXiv] 

[25] 
On Ulam stability (joint with Marc Burger and Narutaka Ozawa) Israel J. Math. 193 (2013), no. 1, 109–129. [DOI arXiv] 

[24] 
Normal generation and l²Betti numbers of groups (joint with Denis Osin) Math. Ann., Volume 355, Issue 4 (2013), 13311347. [DOI arXiv] 

[23] 
Algebraic Geometry of Topological Spaces I (joint with Guillermo Cortiñas) Acta Math. 209 (2012), no. 1, 83131. [DOI arXiv] 

[22] 
Polynomials with and without determinantal representations (joint with Tim Netzer) Linear Algebra and its Applications 437 (2012) 1579–1595. [DOI arXiv] 

[21] 
Is an irng singly generated as an ideal? (joint with Nicolas Monod and Narutaka Ozawa) International Journal of Algebra and Computation, Volume 22, Issue No. 4., (2012) 1250036. [DOI arXiv] 

[20] 
About the metric approximation of Higman's group J. Group Theory, Volume 15, Issue 2 (2012), 301310. [DOI arXiv] 

[19] 
Integer operators in finite von Neumann algebras J. Topology & Analysis 3 (2011), no. 4, 433–450. [DOI arXiv] 

[18] 
Finitedimensional Approximations of Discrete Groups, Abstracts from the Oberwolfach workshop held May 1521, 2011, (organized jointly with Goulnara Arzhantseva and Alain Valette), Oberwolfach Reports, 8(2) (2011), 14291467. [DOI] 

[17] 
A remark about the Connes fusion tensor product Theory Appl. Categ. 25 (2011), no. 2, 3850. [publication arXiv] 

[16] 
Group cocycles and the ring of affiliated operators (joint with Jesse Peterson) Inventiones math., Volume 185, Issue 3 (2011), 561592. [DOI arXiv] 

[15] 
Tracial algebras and an embedding theorem (joint with Tim Netzer) J. Funct. Anal., Volume 259, Issue 11 (2010), 29392960. [DOI arXiv] 

[14] 
A spectral sequence to compute L²Betti numbers of groups and groupoids (joint with Roman Sauer) J. London Math. Soc., Volume 81 (2010), no 3, 747773. [DOI arXiv] 

[13] 
Examples of hyperlinear groups without factorization property Groups Geom. Dyn. 4, no. 1 (2010), 195208. [DOI arXiv] 

[12] 
Low degree bounded cohomology and L²invariants for negatively curved groups Groups Geom. Dyn. 3, no. 2 (2009), 343358. [DOI arXiv] 

[11] 
Homology of free quantum groups (joint with Benoit Collins and Johannes Härtel) C. R. Math. Acad. Sci. Paris 347, Issues 56, March (2009), 271276. [DOI arXiv] 

[10] 
L²Betti numbers for subfactors J. Operator Theory, 61:2, (2009), 295299. [Stable URL arXiv] 

[9] 
Sofic groups and diophantine approximation Comm. Pure Appl. Math., Vol. LXI, (2008), 11551171. [DOI arXiv] 

[8] 
L²cohomology for von Neumann algebras Geom. Funct. Anal., Vol. 18, (2008), 251270. [DOI arXiv] 

[7] 
Comparison between algebraic and topological Ktheory of locally convex algebras (joint with Guillermo Cortiñas) Adv. Math. 218, no 1, (2008), 266307. [DOI arXiv] 

[6] 
L²invariants and Rank Metric C*algebras and Elliptic Theory II, Trends in Mathematics, Birkhäuser Verlag (2007), 267–280. [DOI arXiv] 

[5] 
Bivariant algebraic Ktheory (joint with Guillermo Cortiñas) J. Reine Angew. Math. 610 (2007), 71123. [DOI arXiv] 

[4] 
On a conjecture of Gottlieb (joint with Thomas Schick) Algebr. Geom. Topol. 7 (2007), 779784. [DOI arXiv] 

[3] 
Duality for topological abelian group stacks and Tduality (joint with Ulrich Bunke, Thomas Schick and Markus Spitzweck) Ktheory and Noncommutative Geometry, Valladolid 2006, Series of Congress reports, EMS (2008), 227347. [DOI arXiv] 

[2] 
Algebraic Ktheory and locally convex algebras (joint with Joachim Cuntz) Math. Ann. 334 (2006), no 2, 339371. [DOI arXiv] 

[1] 
Connective Etheory and bivariant homology Thesis, Univ. Münster, MathematischNaturwissenschaftliche Fakultät, 127 p. (2003), Preprint of the SFB 478, Heft 289, [pdf] 