I am Sven Raum, working as associate professor at Stockholm University in Sweden. My research focuses on the interaction between operator algebras, group theory and representation theory. The major link between these topics is created by group operator algebras, such as the reduced group C*-algebras and the group von Neumann algebra. Both can be associated with arbitrary locally compact groups. Other relevant topics for my work are C*-tensor categories, quantum groups, topolgical dynamics, ergodic theory and totally disconnected locally compact groups.
Besides research mathematics, I enjoy thinking about didactics of higher education. In my free time, I like learning languages, doing sports and cooking.
HAOART Seminar
Due to the Corona pandemic, our seminar on Harmonic Analysis, Operator Algebras and Representation Theory (pronounced "Howard") is currently suspended in favor of Wednesday's Zoom Seminar.
All abstracts can be found in the SMC calender:
Link
Spring 2020
-
04.03.2020
Rolf Källström (Högskolan i Gävle)
Decompositions of D-modules over finite maps and the correspondence with representations of finite groups
-
26.02.2020
Michael Hartz (University of Hagen)
Multipliers and operator space structure of weak products
-
05.02.2020
Eskil Rydhe (Lund University)
On Laplace-Carleson embeddings, and some aspects of the Fourier transform
-
29.01.2020
Wushi Goldring (Stockholm University)
Propagating algebraicity of automorphic representations via Langlands functoriality
Autumn 2019
-
04.12.2019
Odysseas Bakas (Lund University)
Remarks on a theorem of Pichorides
-
27.11.2019
Christian Bönicke (University of Glasgow)
Regularity properties for ample groupoids
-
13.11.2019
Yash Lodah (EPFL)
Finitely generated infinite simple groups of homeomorphisms of the real line
-
13.11.2019
Asaf Horev (Stockholm University)
Geometric representation theory and factorization homology on surfaces
(Joint with the NT seminar at 11 o`clock, room 306)
-
30.10.2019
Arno Kret (University of Amsterdam)
Construction of Galois representations for GSO_2n
-
04.09.2019
Ulrik Enstad (University of Oslo)
Time-frequency analysis on the adeles
Spring 2019
-
29.05.2019
Constanze Liaw (University of Delaware)
Generalizations of Aleksandrov-Clark theory
-
22.05.2019
David Kyed (University of Southern Denmark)
Uniqueness questions for C*-norms on group rings
-
15.05.2019
Alan Sola (University of Stockholm)
The Dirichlet space of the bidisk: a survey
-
08.05.2019
Nadia Larsen (University of Oslo)
Phase transitions and arithmetic subalgebras for Hecke C*-algebras from number fields
-
24.04.2019
Magnus Goffeng (University of Gothenburg/Chalmers)
The dynamics and (noncommutative) geometry of Smale spaces
Publications
All my publications can be found on
MathSciNet,
zbMATH and
ArXiv.
Preprints
-
An algebraic characterization of ample type I groupoids
with Gabriel Favre
ArXiv (2020)
-
Amenability, proximality and higher order syndeticity
with Matthew Kennedy and Guy Salomon
ArXiv (2020)
-
Factorial multiparameter Hecke von Neumann algebras and representations of groups acting on right-angled buildings
with Adam Skalski
ArXiv (2020)
Peer-reviewed articles
-
Measure equivalence for non-unimodular groups
with Juhani Koivisto and David Kyed
To appear in Transform. Groups
ArXiv (2018)
-
Measure equivalence and coarse equivalence for locally compact amenable groups
with Juhani Koivisto and David Kyed
To appear in Group, Geom. and Dyn.
ArXiv (2017)
-
Cartan subalgebras in dimension drop algebras
with Selçuk Barlak
J. Inst. Math. Jussieu (2019) and the
ArXiv version
-
Locally compact groups acting on trees, the type I conjecture and non-amenable von Neumann algebras
with Cyril Houdayer
Comm. Math. Helv. 76 (2019) No. 1, 185-219. and the ArXiv version
-
C*-simplicity of locally compact Powers groups
J. Reine Angew. Math. 748 (2019) 173-205 and the ArXiv version
-
C*-superrigidity of 2-step nilpotent groups
with Caleb Eckhardt
Adv. Math. 338 ( 2018), 175-195 and the ArXiv version
-
Higher l2-Betti numbers of universal quantum groups
Julien Bichon and David Kyed
Can. Math. Bull. 61 (2018), No. 2, 225-235 and the ArXiv version
-
Traces on reduced group C*-algebras
with Matthew Kennedy
Bull. Lond. Math. Soc. 49 (2017) No. 6, 988-990 and the ArXiv version
-
L2-Betti numbers of rigid C*-tensor categories and discrete quantum groups
with David Kyed, Stefaan Vaes and Matthias Valvekens
Analysis & PDE 10 (2017), No. 7, 1757-1791 and the ArXiv version
-
On the l2-Betti numbers of universal quantum groups
with David Kyed
Math. Ann. 369 (2017), No. 3-4, 957–975 and the
ArXiv version
-
Cocompact amenable closed subgroups: weakly inequivalent representations in the left-regular representation
Int. Math. Res. Not., (2016), No. 24, 7671-7685 and the ArXiv version
-
The full classification of orthogonal easy quantum groups
with Moritz Weber
Commun. Math. Phy. 341 (2016) No. 3, 751-779 and the
ArXiv
-
Easy quantum groups and quantum subgroups of a semi-direct product quantum group
with Moritz Weber
J. Noncommu. Geo. 9 (2015) No. 4, 1261-1293 and the ArXiv version
-
Asymptotic structure of free Araki-Woods factors
with Cyril Houdayer
Math. Ann. 363 (2015) No. 1-2, 237-267 and the ArXiv version
-
Baumslag-Solitar groups, relative profinite completions and measure equivalence rigidity
with Cyril Houdayer
J. Topol. 8 (2015), 295-313 and the ArXiv
-
The combinatorics of an algebraic class of easy quantum groups
with Moritz Weber
Infin. Dimens. Anal. Quantum Probab. Relat. Top. 17, No. 3 (2014) and the ArXiv version
-
Amalgamated free product type III factors with at most one Cartan subalgebra
with Rémi Boutonnet and Cyril Houdayer
Compositio Math. 150 (2014), 143-174 and the ArXiv version
-
On the classification of free Bogoljubov crossed product von Neumann algebras by the integers
Groups, Geom. and Dyn. 8 (2014) No. 4, 1207-1245 and the ArXiv version
-
Tensor C*-categories arising as bimodule categories of II1 factors
with Sébastien Falguières
Adv. Math. 237 (2013), 331-359 and the ArXiv version
-
Stable orbit equivalence of Bernoulli actions of free groups and isomorphism of some of their factor actions
with Niels Meesschaert and Stefaan Vaes
Expo. Math. 31 (2013), 274-294 and the ArXiv version
-
Isomorphisms and fusion rules of orthogonal free quantum groups and their complexifications
Proc. Amer. Math. Soc. 140 (2012), No. 9, 3207-3218 and the ArXiv version
Other work
-
C*-simplicity after Breuillard, Haagerup, Kalantar, Kennedy and Ozawa
Lecture notes for the Séminaire Bourbaki, January 2019
-
Lecture notes about Creutz-Peterson's "Character rigidity for lattices and commensureators"
Written for the Arbeitsgemeinschaft "Superrigidity" at MFO, 2014
Lecture C3 and Lecture C4
-
A connection between easy quantum groups, varieties of groups and reflection groups
with Moritz Weber
This is an arXiv preprint from 2012 which is not intended for publication. Please cite instead the appropriate article among my remaining work with Moritz.
-
Categories of representations and classification of von Neumann algebras and quantum groups
My PhD thesis under the supervision of Stefaan Vaes submitted in 2013 at KU Leuven.
Talks
Conference talks and lecture series
2019
-
October 2019:
"C*-superrridity"
at MFO, Oberwolfach, Germany during the mini-workshop "Operator algebraic quantum groups".
-
September 2019:
"C*-superrridity"
at BIRS, Banff, Canada during the workshop "Classification problems in von Neumann algebras".
-
July 2019:
"Group C*-algebras: classical and modern"
series of five lectures at the Sophus Lie Center, Nordfjordeid, Norway during the summer school "Analysis, Geometry and PDE".
-
June 2019:
"Cartan subalgebras in dimension drop algebras"
at ICMAT, Madrid, Spain during the International Conference "Operator Algebras, Groups and Applications to Quantum Information".
-
February 2019:
"C*-superrigidity"
two lectures at the Fields Insitute, Toronto, Canada during the Southern Ontario Operator Algebras Seminar 2019.
-
January 2019:
"C*-superrigidity"
series of four lectures at IMP, Tehran, Iran during the workshop "Quantum groups".
2018
-
May 2018:
"C*-superrigidity of 2-step nilpotent groups"
at the University of Münster, Germany, at the occasion of the conference NCGOA 2018.
-
March 2018:
"L2-Betti numbers of universal quantum groups"
at the Université de Caen, France, during the Journées de catégories tensorielles et analyse.
-
February 2018:
"C*-superrigidity"
at the American Institute of Mathematics, San José, CA, USA, during the Workshop "Classification of group von Neumann algebras".
2017
-
October 2017:
"Groups acting on trees: representation theory and operator algebras"
in Sendai, Japan, during the Workshop "Ergodic and Geometric Group theory in Sendai".
-
October 2017:
"C*-superrigidity of virtually Abelian groups"
at IMPAN, Poland, during the Workshop "Operator Algebras, Geometry, and Actions".
-
July 2017:
"C*-superrigidity of virtually Abelian groups"
at Institut Henri Poincaré, France, during the Workshop "Von Neumann algebras and measured group theory".
2016
-
October 2016:
"Operator algebras of locally compact groups acting on trees"
at Université de Bordeaux, France, during the Workshop "Groupes et algèbres de von Neumann".
-
August 2016:
"Non-amenable von Neumann algebras of groups acting on trees"
in MFO, Germany, during the Workshop "C*-algebras".
-
July 2016:
"Operator algebras of locally compact groups acting on trees"
at HIM, Bonn, Germany, during the workshop "Von Neumann algebras".
-
June 2016:
"Operator algebras of locally compact groups acting on trees"
at Université de Paris 6, France, during the conference "Polish groups and geometry".
-
April 2016:
"Operator algebras of locally compact groups acting on trees"
at the Mittag-Leffler Institute, Sweden, during the workshop "Classification and dynamical systems II: Von Neumann Algebras".
-
January 2016:
"Locally compact C*-simple groups"
lecture series at IPM, Tehran, Iran at the occasion of the workshop "C*-dynamics".
2015
-
July 2015:
"The classification of orthogonal easy quantum groups"
in Herstmonceux, UK at the occasion of the Fields institute conference on quantum groups and quantum information theory.
-
June 2015:
"Locally compact C*-simple groups"
in MFO, Germany, during the Workshop "Noncommutative geometry".
-
June 2015:
"Powers group methods for locally compact groups acting on trees"
in Copenhagen, Denmark at the occasion of the workshop "Representation theory of groups, quantum groups, and operator algebras".
-
May 2015:
"Powers group methods for locally compact groups acting on trees"
in Neuchâtel, Switzerland at the Group Theory Day.
-
May 2015:
"Powers group methods for locally compact groups acting on trees"
in Nashville, USA, at the occasion of the conference NCGOA 2015.
-
April 2015:
"Powers group methods for locally compact groups acting on trees"
in Münster, Germany, at the occasion of the workshop "C*-algebras: Structure and Classification".
2014
-
September 2014:
"Baumslag-Solitar groups, relative profinite completions and measure equivalence rigidity"
in Kyoto, Japan, at the occasion of the workshop on recent developments in operator algebras.
-
July 2014:
"The classification of easy quantum groups"
in Amsterdam, the Netherlands, at the occasion of the international workshop on operator theory and its applications.
-
May 2014:
"Structure theory for von Neumann algebras: solidity"
at the University of Franche-Comté in Besançon, France, during the journées d'analyse fonctionelle Besonçon-Neuchâtel.
-
March 2014:
"Character rigidity for lattices and commensurators (after Creutz-Peterson)"
in MFO, Germany, during the Arbeitsgemeinschaft "Superrigidity".
2013 and before
-
December 2013:
"Baumslag-Solitar groups, relative profinite completions, and measure equivalence rigidity"
in Caen, France, at the occasion of the Arbre de Noël.
-
January 2013:
"A duality between easy quantum groups and reflection groups"
in Tokyo, Japan, at the occasion of a workshop on operator algebras.
-
September 2012:
"Sur la classification des produits croisés de Bogoliubov libre"
in Lyon, France, at the occasion of the meeting of the ANR project NEUMANN.
-
May 2011:
"All finite C*-tensor categories are bimodule categories of a II1 factor"
in Paris, France, at the occasion of the Franco-Italien meeting of GDRE GREFI-GENCO.
-
September 2010:
"Is every finite C*-tensor category the bimodule category of a II1 factor?"
in Caen, France, at the occasion of the focused semester on quantum groups of the EU Noncommutative Geometry Network.
-
September 2010:
"Every finite C*-tensor category is the bimodule category of a II1 factor"
in Brussels, Belgium, at the occasion of the PhD day of the Belgium Mathematical Society.
-
February 2010:
"Fusion rules of free orthogonal quantum groups"
in Cardiff, UK, at the occasion of the period on planar algebras and physics.
-
January 2010:
"Fusion rules of free orthogonal quantum groups"
in Copenhagen, Denmark, at the occasion of the masterclass on von Neumann algebras and group actions.
Colloquium and seminar talks
2020
-
October 2020:
"Structure of Hecke von Neumann algebra and appications to representation theory"
in the Tokyo-Kyoto online operator algebra seminar.
-
July 2020:
"C*-superrigidity"
in the UK virtual operator algebra seminar.
-
February 2020:
"From Poisson boundaries to proximal boundaries"
at the University of Copenhagen, Denmark, in the operator algebra seminar.
2019
-
December 2019:
"C*-superrigidity of 2-step nilpotent groups"
at University Paris-Sud, France, in the research seminar GAN.
-
April 2019:
"C*-superrigidity of 2-step nilpotent groups"
at the University of Glasgow, UK, in the analysis seminar.
-
March 2019:
"C*-superrigidity of 2-step nilpotent groups"
at the University of Oslo, Norway, in the operator algebra seminar.
-
January 2019:
"C*-simpllicity"
at IHP, Paris, France, in the Séminaire Bourbaki.
2018
-
December 2018:
"Superrigidity for group operator algebas"
at the University of Waterloo, Canada, in the Pure Math Colloquium.
-
August 2018:
"C*-superrigidity of 2-step nilpotent groups"
at Chalmers, Gothenburg, Sweden, in the Analysis and Probability seminar.
-
May 2018:
"C*-superrigidity of nilpotent groups"
at EPFL, Switzerland, in the topology seminar.
-
February 2018:
"C*-superrigidity"
at RIMS, Kyoto University, Japan.
-
February 2018:
"Cartan subalgebras in dimension drop algebras"
at Nagoya University, Japan, in the research seminar of the analysis group.
2017
-
November 2017:
"Cartan subalgebras in dimension drop algebras"
at Copenhagen University, Denmark, in the research seminar of the operator algebra work group.
-
November 2017:
"Groups acting on trees: representation theory and operator algebras"
at the University of Southern Denmark, Odense, Denmark, in the research seminar of the operator algebra work group.
-
August 2017:
"C*-superrigidity of virtually abelian groups"
at Chiba University, Japan, in the analysis seminar.
-
June 2017:
"Groups acting on trees: representation theory and operator algebras"
at the Isaac Newton Institute, Cambridge, UK, in the operator algebras seminar.
-
May 2017:
"C*-superridigity of virtually abelian groups"
at Université de Neuchâel, Switzerland, in the groups and analysis seminar.
2016
-
December 2016:
"On the type I conjecture for groups acting on trees"
at EPFL, Switzerland, in the EGG seminar.
-
November 2016:
"On the type I conjecture for groups acting on trees"
at ETH Zürich, Switzerland, in the geometry seminar.
-
April 2016:
"Algèbres d'opérateurs de groupes agissants sur les arbres"
at Université Catholique de Louvain, Belgium, in the group theory seminar.
-
April 2016:
"C*-simplicity: from discrete to locally compact groups"
at Hokkaido University, Japan, in the analysis research seminar.
-
March 2016:
"C*-simple and non-C*-simple locally compact groups"
at University Paris-Sud, France, in the research seminar GAN.
-
March 2016:
"C*-simple and non-C*-simple locally compact groups"
at Copenhagen University, Denmark, in the research seminar of the operator algebra work group.
-
March 2016:
"C*-simple and non-C*-simple locally compact groups"
at EPFL, Switzerland, in the research seminar for ergodic and geometric group theory.
2015
-
November 2015:
"Locally compact C*-simple groups"
at the University of Münster, Germany, in the research seminar of the noncommutative geometry workgroup.
-
October 2015:
"Locally compact C*-simple groups"
at the University of Glasgow, Scotland, in the analysis seminar.
-
July 2015:
"Generalised symmetries of quantum spaces"
at Keio University in Yokohama, Japan, in the monthly colloquium of the math department.
-
July 2015:
"C*-simplicity of locally compact Powers groups"
at Ochanomizu University in Tokyo, Japan, in the operator algebras seminar.
-
January 2015:
"Free probability aspects of easy quantum groups"
at Kyushu University in Fukuoka, Japan, in the operator algebras seminar.
-
January 2015:
"Character rigidity for lattices in higher rank Lie groups (after Creutz-Peterson and Peterson)"
at RIMS in Kyoto, Japan, in the Kansai operator algebras seminar.
2014
-
October 2014:
"The classification of easy quantum groups"
at Tokyo University, Japan, in the operator algebras seminar.
2013 and before
-
November 2013:
"The classification of orthogonal partition quantum groups (easy quantum groups)"
at the University of Franche-Comté in Besançon, France, in the functional analysis seminar.
-
May 2013:
"Group von Neumann algebras of locally compact HNN-extensions"
at the University of Oxford, UK, in the junior geometric group theory seminar.
-
December 2012:
"What is ... superrigidity?"
at KU Leuven, Belgium, in the PhD-Colloquium.
-
November 2012:
"On the classification of free Bogoliubov crossed products of the integers"
at Université catolique de Louvain, Belgium, in the group theory seminar.
-
October 2012:
"Tensor C*-categories arising as bimodule categories of a II1 factor"
at the University of Münster, Germany, in the research seminar of the noncommutative geometry workgroup.
-
June 2012:
"Von Neumann algebras and their bimodule categories"
at Saarland University, Germany, in the functional analysis seminar.
-
May 2012:
"Les C*-catégories tensorielles, qui sont les catégories de bimodules d'un facteur II1"
at Institut de Mathématiques de Jussieu, Paris, France, in the operator algebras seminar.
-
April 2012:
"Tensor C*-categories arising as bimodule categories of II1 factors"
at KU Leuven, Belgium, in the operator algebras seminar.
-
June 2009:
"On the corepresentation theory of complexified quantum groups"
at KU Leuven, Belgium, in the operator algebras seminar.
Teaching and supervision
Taught courses
Supervision of PhD students
Supervision of Master theses
2017/18 |
On groups of type I |
2016/17 |
C*-simplicity and factorial group von Neumann algebras |
2011/12 |
Equivalence relations with prescribed fundamental group (co-supervision) |
2010/11 |
Orbit equivalence of Bernoulli actions over free groups (co-supervision) |
2009/10 |
There is no universal II1 factor (co-supervision) |
Supersion of Bachelor theses
2019/20
|
Quantum computing: From Shor’s algorithm to the hidden subgroup problem
The travelling salesman in Sweden (teacher student)
Classical finite simple groups
The spectral theorem for normal operators
|
2018/19
|
Wallpaper groups (teacher student)
|
2017/18
|
K-theory and Bott periodicity
|
2016/17
|
Classification of closed surfaces
|
Teaching material
Lie groups. Spring term 2018
Homology and Cohomology. Spring term 2018
Abstract harmonic analysis. Spring term 2017
Abstrakte harmonische Analysis. Sommersemester 2016
Von Neumann Algebren und messbare Gruppentheorie. Wintersemester 2015/16
Vita
Born on 9th April 1985 in Kassel, Germany.
Current Employment
Since Sep 2018 |
Associate Professor at Stockholm University, Sweden |
Previous Employment
Sep - Dec 2020 |
Visiting Professor at IMPAN, Poland |
2016 - 2018 |
Lecturer at EPFL, Switzerland |
2015 - 2016 |
Marie Curie International Outgoing Fellow at the University of Münster, Germany |
2014 - 2015 |
Marie Curie International Outgoing Fellow at RIMS, Kyoto, Japan |
2013 - 2014 |
Post doctoral scholar at ENS Lyon, France |
2009 - 2013 |
PhD scholar at KU Leuven, Belgium |
2007 - 2009 |
Student teaching assistant at the University of Münster |
Education
Oct 2019 |
Docent in Mathematics at Stockholm University, Sweden |
Sep 2009 - Jun 2013 |
PhD in Mathematics at KU Leuven, Belgium |
Oct 2005 - May 2009 |
Diplom Mathematik at the University of Münster, Germany |
Languages
German |
Mother tongue |
English |
Fluent |
French |
Fluent (B2) |
Dutch |
Fluent (C1) |
Swedish |
Good |
Japanese |
Baisc knowledge (JLPT N5) |
Persian |
Basic knowledge |
Links
Coauthors
Places
Family