# Researchers

## Faculty | |||||||

Dr. D. Ara | (algebraic topology) | RU | Homepage | Publications | |||

Prof. Dr E. van den Ban | (Lie groups) | UU | Biography | Homepage | Publications | ||

Dr. R. Bocklandt | UvA | ||||||

Dr. S. Brain | (Mathematical Physics) | RU | Biography | Publications | |||

Dr. G. Carlet | (Integrable systems) | UvA | Homepage | Publications | |||

Dr. G. Cavalcanti | (symplectic and complex geometry) | UU | Biography | Homepage | Publications | ||

Prof. Dr. G. Cornelissen | (algebraic geometry) | UU | Biography | Homepage | Publications | ||

Prof. Dr. M. Crainic | (differential geometry, Lie theory) | UU | Homepage | Publications | |||

Prof Dr R.H. Dijkgraaf | (mathematical physics) | UvA | Biography | Homepage | Publications | ||

Prof Dr C.F. Faber | (algebraic geometry) | UU | Publicaties | ||||

Dr. P. Frejlich | (Poisson Geometry and Topology) | UU | |||||

Prof.Dr. G. van der Geer | (algebraic geometry) | UvA | Biography | Homepage | Publications | ||

Dr. M. Groth | (algebraic topology) | RU | Biography | Homepage | Publications | ||

Dr. J.J. Gutiérrez | (algebraic topology) | RU | Biography | Homepage | Publications | ||

Dr. Y. Harpaz | (algebraic topology) | RU | Biography | Homepage | Publications | ||

Prof. Dr. G.J. Heckman | (Lie theory) | RU | Biography | Homepage | Publications | ||

Dr. G.F. Helminck | (Lie groups) | UvA | Homepage | Publications | |||

Dr. A. Henriques | (topology and mathematical physics) | UU | Homepage | Publications | |||

Dr. S. Igonin | (integrable systems) | UU | Publications | ||||

Dr. B. Janssens | (differential geometry/representation theory) | UU | Biography | Homepage | publications | ||

Dr. M. de Jeu | (representation theory) | Leiden | Homepage | Publications | |||

Dr. W. van der Kallen | (algebraic groups) | UU | Biography | Homepage | Publications | ||

Prof. Dr. H.T. Koelink | (quantum groups) | RU | Biography | Homepage | Publications | ||

Prof. Dr. N.P. Landsman | (mathematical physics) | RU | Biography | Homepage | Publications | ||

Dr. J. van de Leur | (integrable systems) | UU | Homepage | Publications | |||

Dr. S. Liu | (representation theory) | UvA | Biography | Homepage | Publications | ||

Prof. Dr. E.J.N. Looijenga | (geometry) | UU | Biography | Homepage | Publications | ||

Prof.dr. H. Maassen | (mathematical physics) | RU/UvA | Homepage | Publications | |||

Prof. Dr. I. Moerdijk | (topology) | RU | Biography | Homepage | Publications | ||

Prof.Dr. B. Moonen | (algebraic geometry) | RU | Biography | Homepage | Publications | ||

Dr. I. Marcut | (differential geometry) | UU | Biography | ||||

Dr. M. Mueger | (mathematical physics) | RU | Biography | Homepage | Publications | ||

Prof. D. Notbohm | (pure mathematics) | VU | Biography | Homepage | Publications | ||

Prof. Dr. E.M. Opdam | (representation theory) | UvA | Biography | Homepage | Publications | ||

Dr. H. Posthuma | (mathematical physics) | UvA | Homepage | Publications | |||

Dr. M. Prezma | (algebraic topology) | RU | |||||

Prof.Dr. N. Reshetikhin | UvA | Homepage | Publications | ||||

Dr. D. Roytenberg | (derived geometry with mathematical physics) | UU | Biography | Homepage | Publications | ||

Dr. U. Schreiber | (higher structures in mathematical physics) | RU | Biography | Homepage | Publications | ||

Dr. D. Sepe | (Integrable Hamiltonian Systems) | UU | Homepage | ||||

Prof. S. Shadrin | (geometry) | UvA | Homepage | Publications | |||

Prof. Dr. D. Siersma | (singularity theory) | UU | Biography | Homepage | Publications | ||

Dr. M. Solleveld | (representation theory) | RU | Biography | Homepage | Publications | ||

Prof. Dr. J.H.M. Steenbrink | (algebraic geometry) | RU | Biography | Homepage | Publications | ||

Dr. J. Stienstra | (algebraic geometry) | UU | Biography | Homepage | Publications | ||

Prof.dr. J. Stokman | (quantum groups) | UvA/RU | Homepage | Publications | |||

Dr. W. van Suijlekom | (mathematical physics) | RU | Biography | Homepage | Publications | ||

Dr. M. Tavakol | (Algebraic Geometry) | UvA | Homepage | Publications | |||

Dr. R. van der Veen | (representation theory) | UvA | Biography | Homepage | Publications | ||

Dr. B.H.M. Vlaar | () | UvA | |||||

Dr. F. Ziltener | (Symplectic Geometry) | UU | Biography | Homepage | Publications | ||

## In Memoriam |
|||||||

Dr. F. Clauwens | April 17th, 1950 - July 22nd, 2011 | (algebraic topology) | RU | Biography | Publications | ||

Prof Dr J.J. Duistermaat | December 20th, 1942 - March 19th, 2010 | (geometric analysis) | UU | In Memoriam | Publications | ||

## PhD students |
|||||||

Noud Aldenhoven | RU | ||||||

Arjen Baarsma | UU | ||||||

Dana Balibanu | UU | ||||||

Matija Basic | RU | ||||||

Arie Blom | UvA | ||||||

Jord Boeijink | RU | ||||||

Thijs van den Broek | RU | ||||||

Giovanni Caviglia | RU | ||||||

Johan Commelin | RU | ||||||

Petr Dunin-Barkovskiy | UvA | ||||||

Yongqi Feng | UvA | ||||||

Marcelo Goncalves de Martino | UvA | ||||||

Roberta Iseppi | RU | ||||||

Valentijn Karemaker | UU | ||||||

Ralph Klaasse | UU | ||||||

Sebastian Klein | UU | ||||||

Jules Lammers | UU | ||||||

Joey van der Leer Duran | UU | ||||||

Danilo Lewanski | UvA | ||||||

Bert Lindenhovius | RU | ||||||

João Nuno Mestre | UU | ||||||

Joost Nuiten | RU | ||||||

Boris Osorno Torres | UU | ||||||

Alexandr Popolitov | UvA | ||||||

Arie Peterson | UvA | ||||||

Frank Roumen | RU | ||||||

Rudy Salomon | UvA | ||||||

Shan Shah | UU | ||||||

Sohail Sheikh | RU | ||||||

Dali Shen | UU | ||||||

Julius Witte | RU | ||||||

Roy Wang | UU | ||||||

Sander Wolters | RU | ||||||

Qizheng Yin | UvA | ||||||

Ori Yudilevich | UU | ||||||

## Former PhD students | |||||||

Camillo Arias Abad | UU | ||||||

Representations up to homotopy and cohomology of classifying spaces | advisors: Ieke Moerdijk and Marius Crainic | December 2008 | |||||

Rogier Bos | RU | ||||||

Groupoids in geometric quantization | advisor: Klaas Landsman | September 2007 | |||||

Alex Boer | UU | ||||||

A unitary structure for the graded quotient of conformal coblocks | advisor: Eduard Looijenga | November 2008 | |||||

Fokko van de Bult | UvA | ||||||

Hyperbolic Hypergeometric Functions | advisor: E.M. Opdam, J.V. Stokman | November 2007 | |||||

Alexandr Buryak | UvA | ||||||

Topology of the moduli space of curves and integrable hierarchies | advisor: Sergey Shadrid | April 2013 | |||||

Jakub Byszewski | UU | ||||||

Cohomological Aspects of Equivalent Deformation Theory | advisor: Gunther Cornelissen | Juni 2009 | |||||

Martijn Caspers | RU | ||||||

Noncommutative integration on locally compact quantum groups | advisor: Erik Koelink | June 2012 | |||||

David Carchedi | UU | ||||||

Categorical Properties of Topological and Differentiable Stacks | advisor: Ieke Moerdijk | September 2011 | |||||

Bart van den Dries | UU | ||||||

Degenerations of cubic fourfolds and holomorphic symplectic geometry | advisor: Eduard Looijenga | Maart 2012 | |||||

Pieter Eendebak | UU | ||||||

Contact Structures of Partial Differential Equations | advisor: Hans Duistermaat | January 2007 | |||||

Erdal Emsiz | UvA | ||||||

Affine Weyl groups and integrable systems with delta-potentials | advisors: Erik Opdam and Jasper Stokman | August 2006 | |||||

Chris Heunen | RU | ||||||

Categorical quantum models and logics | advisors: Klaas Landsman and Bart Jacobs | January 2010 | |||||

Peter Hochs | RU | ||||||

Quantisation commutes with reduction for cocompact Hamiltonian group actions | advisors: Klaas Landsman and Gert Heckman | April 2008 | |||||

Maarten Hoeve | UvA | ||||||

Stratifications on moduli spaces of abelian varieties and Deligne-Lusztig varieties | advisors: Gerard van der Geer and Ben Moonen | June 2010 | |||||

Lotte Hollands | UvA | ||||||

Topological Strings and Quantum Curves | advisor: Robbert Dijkgraaf | September 2009 | |||||

Bas Janssens | UU | ||||||

Transformation & Uncertainty. Some thoughts on Quantum Probability Theory, Quantum Stochastics, and Natural Bundles | advisor: Roberto Fernández | October 2010 | |||||

Jan Willem de Jong | UU | ||||||

Zeta function rigidity; a view from noncommutative geometry | advisor: Gunther Cornelissen | September 2011 | |||||

Janne Kool | UU | ||||||

Curves and Dynamics | advisor: Gunther Cornelissen | May 2013 | |||||

Niels Kowalzig | UvA/UU | ||||||

Hopf Algebroids and Their Cyclic Theory | advisors: Ieke Moerdijk and Klaas Landsman | June 2009 | |||||

Job Kuit | UU | ||||||

Radon transformation on reductive symmetric spaces: support theorems | advisor: Erik van den Ban | May 2011 | |||||

Oliver Lorscheid | UU | ||||||

Toroidal automorphic forms for function fields | advisor: Gunther Cornelissen | May 2008 | |||||

Andor Lukacs | UU | ||||||

Algebraïsche structuren in de topologie | advisor: Ieke Moerdijk | October 2010 | |||||

Jan Manschot | UvA | ||||||

Partition function for supersymmetric black holes | advisor: E.P. Verlinde | December 2008 | |||||

Michel van Meer | UvA | ||||||

Bispectral quantum Knizhnik-Zamolodchikov equations | advisor: E. Opdam and J. Stokman | July 2010 | |||||

Ioan Marcut | UU | ||||||

Normal forms in Poisson geometry | advisor: Marius Crainic | February 2013 | |||||

Miek Messerschmidt | Leiden | ||||||

Positive representations on ordered Banach spaces | advisor: M. de Jeu, Promotor: A. Doelman | November 2013 | |||||

Pieter Naaijkens | RU | ||||||

Anyons in infinite quantum systems | advisor: K. Landsman, M. Mueger | May 2012 | |||||

Andrey Opimakh | UvA | ||||||

Deforming commuting directions in the space of Z x Z-matrices | advisor: Niclai Reshetikhin and Gerard Helminck | February 2011 | |||||

Maarten van Pruijssen | RU | ||||||

Matrix valued orthogonal polynomials related to compact Gel'fand pairs of rank one |
advisor: Gert Heckman, Erik Koelink, copromotor: Pablo Romn | December 2012 | |||||

Vincent van der Noort | UU | ||||||

Analytic parameter dependence of Harish-Chandra modules for real reductive Lie groups: A family affair | advisor: Erik van den Ban | December 2009 | |||||

Maria Amelia Salazar P. | UU | ||||||

Pfaffian | advisor: Marius Crainic | May 2013 | |||||

Loek Spitz | UvA | ||||||

Hurwitz numbers, moduli of curves, topological recursion, Givental's theory and their relations | advisor: Sergey Shadrin | January 2014 | |||||

Roland van der Veen | UvA | ||||||

Asymptotics of quantum spin networks | advisor: Eric Opdam and Stavros Garoufalidis | September 2010 | |||||

Alexander Quintero Velez | UU | ||||||

Equivalence of D-brane categories | advisors: Hans Duistermaat and Jan Stienstra | March 2009 | |||||

Sheer El-Showk | UvA | ||||||

Puzzles in Quantum Gravity. What can a Black Hole Microstates teach us about Quantum Gravity? | advisor: J. de Boer | September 2009 | |||||

Maarten Solleveld | UvA | ||||||

Periodic cyclic homology of affine Hecke algebras | advisor: Eric Opdam | January 2007 | |||||

Christian Svensson | Leiden | ||||||

Crossed product algebras associated with topological dynamical systems | advisor: Marcel de Jeu | March 2009 | |||||

Rogier Swierstra | UU | ||||||

Moduli spaces of cubic hypersurfaces through a period map | advisor: Eduard Looijenga | April 2008 | |||||

Giorgio Trentinaglia | UU | ||||||

Tannaka duality for Lie groupoids | advisor: Ieke Moerdijk | September 2008 | |||||

Jan Jitse Venselaar | UU | ||||||

Classification and equivalences of noncommutative tori and quantum lens spaces | advisor: Gunther Cornelissen | August 2012 | |||||

Ittay Weiss | UU | ||||||

Dendroidal Sets | advisor: Ieke Moerdijk | September 2007 | |||||

Roel Willems | RU | ||||||

Polynomiale automorfismen en Mathieu-deelruimtes | advisor: Gert Heckman | July 2011 |

Marten Wortel | Leiden | ||||

Group representations in Banach spaces and
Banach lattices |
advisor: Sjoerd Verduyn Lunel, copromotors: Marcel de Jeu, Ben de Pagter | April 2012 | |||

## Advisors and Fellows

### Board of Advisors:

Prof Dr G. 't Hooft (Theoretical physics, Utrecht)

Prof Dr V. Kac (MIT, USA)

Prof Dr M. Kontsevich (IHES, France)

Prof Dr A.N. Schellekens (Theoretical physics, Nijmegen, and NIKHEF)

Prof Dr E. Verlinde (Theoretical physics, Amsterdam)

Prof Dr A. Weinstein (UC Berkeley, USA)

Prof Dr E. Witten (Princeton, USA)

### Fellows:

Prof Dr C.F. Faber (Utrecht University, algebraic geometry)

Prof Dr A.J. de Jong (Columbia, algebraic geometry)

Prof Dr L.N.M. van Geemen (Milan, Italy, algebraic geometry)

Prof Dr R. Sjamaar (Cornell University, USA, symplectic geometry)

Prof Dr D. van Straten (University of Mainz, Germany, singularity theory)

# Curricula Vitae

### Erik van den Ban

Erik van den Ban (1956) studied mathematics at Utrecht University where he obtained his PhD in 1982. In the academic year 1982/1983 he was a member at the Institute for Advanced Study in Princeton. After having been post-doc at the Mathematical Centre (now CWI) in Amsterdam he became assistent professor in the Department of Mathematics of Utrecht University. He occupied short term visiting positions in Berkeley and in Copenhagen and in 1995 a four month visiting position at the Mittag-Leffler Institute in Djursholm, Sweden. In 2002 he was promoted to associate professor and in 2007 to professor in Lie theory.

Van den Ban's research area is analysis and representation theory for reductive Lie groups and symmetric spaces. He investigated the asymptotic behaviour of matrix coeffients, and the role of the principal series of representations in harmonic analysis on reductive symmetric spaces. In a long collaboration with Henrik Schlichtkrull from the University of Copenhagen he succeeded in obtaining Plancherel and Paley-Wiener theorems for such spaces.

Van den Ban is editor of Transactions and Memoirs of the American Mathematical Society.

### Simon Brain

Simon Brain studied Mathematics at the University of Oxford from 1996 to 2000 and was awarded his PhD in 2005 by the same institution, with a dissertation supervised by Dr K.C. Hannabuss. Brain has previously held post-doc positions in SISSA (Trieste, Italy), the University of Luxembourg and the University of Trieste. Since December 2013 he is a post-doc at the IMAPP in Nijmegen. Brain's research is in the field of noncommutative geometry; in particular the study of gauge theories on noncommutative four-manifolds.

### Gil Cavalcanti

Gil Cavalcanti (1977) did his D.Phil. in Oxford University under the supervision of Nigel Hitchin and finished his degree in 2004. After that he held an EPSRC scholarship to work in Oxford as Hitchin's post-doctoral research assistant from 2005 to 2008. At the same time he was also a Junior Research Fellow in Jesus College. At the end of his post-doc, in 2007, Cavalcanti was awarded a Veni grant from NWO and a Marie Curie IEF grant from the European Research Council to work in the mathematics department in Utrecht, from 2008. In 2009 Cavalcanti was appointed as assistant professor in Utrecht.

Cavalcanti's area of research is generalized complex geometry and nearby areas of complex and symplectic geometry. He is currently working on questions concerning generalized complex structures on 4-manifolds, including a possible Lefschetz fibration structure for those as well as differential invariants which might be associated to such manifolds. Some of his long term collaborators are Marco Gualtieri (University of Toronto) and Henrique Bursztyn (IMPA).

### Frans Clauwens

Frans Clauwens (1950) studied mathematics at the Katholieke Universiteit Nijmegen (now Radboud Universiteit), where he obtained his PhD in 1975 and became an assistant professor. His research interests include algebraic and differential topology, in particular surgery theory, algebraic K- theory and algebraic L-theory. He is researching the peculiarities of lambda-rings with a view to using these to provide methods for calculating K- and L- groups in the nonfinite cases.

### Gunther Cornelissen

Gunther Cornelissen (1971) works on automorphic forms over global function fields, the theory of non-archimedean uniformization and its links with non-commutative geometry, deformation theory of group actions on curves and complexity questions about rational points.

He received his Ph.D. in 1997 from the University of Gent (Belgium) under the supervision of Jan Van Geel and Ernst-Ulrich Gekeler on a grant from the Belgian National Science Foundation, and then spent four years at the Max-Planck-Institute in Bonn (Germany), before accepting a position as lecturer-researcher at the University of Utrecht in 2001. In 2004-2009, he is the principal investigator of a VIDI-Innovational Research grant from the Dutch National Science Foundation. In 2007, he took up a Profile Chair in Mathematical Physics (interaction between mathematical physics and arithmetic geometry) at Utrecht University, initially funded by the GQT-cluster.

A description of research interest can be found here.

### Robert Dijkgraaf

Robbert Dijkgraaf (1960) holds the chair of Mathematical Physics at the University of Amsterdam since 1992 (and is since 1998 Faculty Professor in the Faculty of Science). He studied theoretical physics and mathematics in Utrecht, where he obtained his PhD cum laude under supervision of Gerard 't Hooft in 1989. Subsequently he held a postdoctoral position at Princeton University and was a long-term member at the Institute for Advanced Study. He has been a visiting professor in Berkeley, MIT, IAS, among others. Dijkgraaf research group works in string theory, quantum gravity, and the interface of mathematics and particle physics. He manages the FOM programs "Mathematical Physics" and "String Theory and Quantum Gravity."

Dijkgraaf gave an invited lecture at the ICM in Berlin (1998) and was a plenary lecturer at the International Congress of Mathematical Physics (London, 2000) and the European Congress of Mathematics (Barcelona, 2000). Dijkgraaf is a member of the Royal Netherlands Academy of Arts and Sciences (KNAW) and the Koninklijke Hollandse Maatschappij van Wetenschappen. He was the recipient of the 2001 Physica Prize of the Dutch Physical Society. In 2003 he was awarded the Spinoza Prize, the highest scientific award in the Netherlands.

Dijkgraaf is editor of Nuclear Physics B, Journal of Differential Geometry, Journal of Geometry and Physics, Advances in Theoretical and Mathematical Physics, International Mathematical Research Notices, Journal of Mathematical Physics, Reviews of Mathematical Physics, Elsevier Mathematical Library, Academische Boekengids, and was an editor of Communications in Mathematical Physics from 1992 to 2002. Dijkgraaf was a director of the spring school at the ICTP Trieste (1992-1996) and has served on various international scientific committees among other for the Isaac Newton Institute for Mathematical Sciences in Cambridge, Max-Planck-Institut fur Mathematik in Bonn, Erwin Schroedinger Institut fur Mathematische Physik in Vienna, and the International Review of UK Mathematics.

### Hans Duistermaat

J.J. (Hans) Duistermaat (1942) studied mathematics at Utrecht University from 1959-65 and obtained his PhD degree there in 1968. After a postdoctoral year 1969-70 in Lund (Sweden), where he learned Fourier integral operators from Hörmander, he went in 1971-74 to Nijmegen, where he became full professor in 1972. In 1974 he returned to Utrecht on the chair of professor Freudenthal, where he has stayed until now.

He became member of the KNAW (Royal Dutch Academy of Arts and Sciences) in 1982, and Academy Professor in 2004, which means that he is supposed to do research without being distracted by administrative duties until his retirement.

He has been `promotor' of 17 PhD students, of which 10 as the main thesis advior. Several of these were NWO projects, and one was research paid by Shell.

Duistermaat's current interests include classical mechanics, symplectic differential geometry, high-frequency asymptotics of solutions of linear partial differential equations, the differential geometric theory of arbitrarily nonlinear partial differential equations, and stochastically perturbed dynamical systems. Apart from 43 articles in refereed international journals, he has written 7 books, of which probably the introduction to Fourier integral operators is the most well known. His best known research is probably his article with Guillemin on spectra of elliptic operators and periodic bicharacteristics, his article with Heckman on the Duistermaat-Heckman formula, and his article with Grünbaum on the bispectral problem.

At the moment his main editing task is being co-ordinating editor of Indagationes Mathematicae, the mathematics journal of the KNAW.

### Gerard van der Geer

Gerard van der Geer (1950) studied mathematics at the University of Leiden. He received his PhD from that university in 1977. Subsequently he worked at the Sonderforschungsbereich at Bonn University and then got a position at the University of Amsterdam, where he has been full professor in Algebra since 1987. He spent long visits at research institutes like MSRI at Berkeley and the Max-Planck-Institut at Bonn, and foreign universities like Harvard, the University of Tokyo and Kyoto University.

Van der Geer has been managing editor of Compositio Mathematica for more than ten years and is editor of Geometriae Dedicata and of the EMS Monograph series. He is member of the scientific committees of the Max-Planck-Institut fuer Mathematik in Bonn and the Research Institute in Oberwolfach. He has successfully supervised seven PhD theses (including those of C. Faber and G. Farkas) and is currently supervising another three. He was one of the initiators of the big NWO projects "Moduli" and "Algebraic curves and Riemann surfaces". He started the well-known series of Texel conferences.

Van der Geer has worked on Hilbert modular surfaces, on which he wrote the well-known volume "Hilbert Modular Surfaces" in the Ergebnisse series of Springer, on the Schottky problem, where he contributed with van Geemen a conjectural solution, on moduli of curves and abelian varieties, and on curves over finite fields. His current research deals with cohomology of local systems on moduli spaces and with moduli of Calabi-Yau varieties. He has published over 50 research papers in refereed journals.

### Gert Heckman

Gert Heckman (1953) studied mathematics at the University of Leiden, where he obtained his PhD in 1980. After a period of 2 years as postdoc at MIT, he returned to Leiden as assistant professor until 1988, with a half year interruption as visiting associate professor at Universite Paris 7. From 1989 until now he has been at the University of Nijmegen, from 1999 on as professor of pure mathematics. He has trained 3 PhD students.

Heckman' s research interests include symplectic geometry and geometric quantization, algebraic geometric analysis (hypergeometric functions, differential Galois theory), and representation theory of reductive groups. About his joint work with Eric Opdam he was invited to give lectures at Seminair Bourbaki (1997) in Paris, and Current Developments in Mathematics (1996) at Harvard.

### Bas Janssens

Bas Janssens studied mathematics and physics in Nijmegen, after which he did his PhD in mathematics in Utrecht (2010). He then had postdoc positions in Hamburg (2011/2012) and Erlangen (2012/2013), and is currently a postdoc in Utrecht.

His area of research centers around cohomology and representation theory of infinite dimensional Lie algebras of geometrical nature, such as gauge algebras and the Lie algebra of (hamiltonian) vector fields. Other interests include quantum probability theory and string geometry.

### Wilberd van der Kallen

Wilberd van der Kallen studied mathematics (and undergraduate physics) at the Rijksuniversiteit Utrecht. There he also obtained his PhD in 1973 under professor Springer. He is a member of the Utrecht Mathematics Department since 1969. He has worked for some time in algebraic K-theory. His current interest involves representation theory of algebraic groups. He has repeatedly visited Northwestern University (Evanston, Illinois, USA) and the Tata Institute for Fundamental Research (Mumbay, India).

The main research interest of van der Kallen is in representations of reductive algebraic groups like the group of n by n matrices of determinant one. An important tool in his work has been the method of Frobenius splittings from algebraic geometry. Van der Kallen has conjectured connections between invariant theory, a topic from the nineteenth century, and the homological algebra of the represesentations of reductive algebraic groups.

### Erik Koelink

Personal data

Born April 30, 1964, Coevorden, the Netherlands Married, 3 children

Scientific education

1982-1987: Mathematics study at the Rijksuniversiteit Groningen. Minor: computer science. Master thesis (in dutch) Singular integral operators in analysis under prof. E.G.F. Thomas

1987: teaching degree

1988-1991: PhD-student mathematics at the Universiteit Leiden. PhD-thesis On quantum groups and q-special functions (December 4, 1991). Promotores: prof. G. van Dijk and prof. T.H. Koornwinder.

Work experience

1985-1987: student-assistant at the math department of Faculty of Econometry and Actuarial Sciences of the Rijksuniversiteit Groningen.

1988-1991: aio (PhD-student) at the math department of the Universiteit Leiden.

1992-1993: engineer at the National Aerospace Laboratory Amsterdam at the department Mathematical Modelling and Methods.

1993-1995: post-doc at the Katholieke Universiteit Leuven, Belgium, hosted by prof. W. Van Assche and prof. A. Van Daele

1995-1998: postdoc at the Universiteit van Amsterdam, hosted by prof. T.H. Koornwinder.

1998-2007: assistant (later associate) professor at Technische Universiteit Delft

2007-onwards: professor at Radboud Universiteit.

### Klaas Landsman

N.P. (Klaas) Landsman (1963) studied theoretical physics and mathematics at the University of Amsterdam, and got his PhD degree cum laude from the same institution in 1989. He worked at the University of Cambridge from 1989-1997, initially as a Research Assistant in theoretical physics and subsequently as a 5-year Advanced Research Fellow in mathematics. He interrupted his stay at Cambridge for a year in 1993-94 to work in Hamburg. He returned to Amsterdam in 1997 as a KNAW Fellow, and was appointed full professor of mathematical physics in 2002. From September 2004 he will be a professor of analysis at the University of Nijmegen.

His research Awards include an SERC Advanced Fellowship, an Alexander von Humboldt Fellowship a KNAW Fellowship, and an NWO Pioneer Grant of 1 ME. Over the last five years he held four additional project grants from NWO and/or FOM. He has been a Board Member of the Dutch Association for Mathematical Physics since 2000, and has been running a Master's Degree Program in Mathematical Physics at Amsterdam since 2001. He supervised four PhD students at Cambridge and Amsterdam, and is currently training three more.

Landsman's active research interests include noncommutative geometry, geometric and deformation quantization, index theory, Lie groupoids and algebroids, particularly in connection with each other. He is the author of the acclaimed monograph Mathematical Topics Between Classical and Quantum Mechanics (Springer, New York, 1998), and is the author of more than 50 refereed papers. He founded a series of conferences on the quantization of singular Poisson spaces at Oberwolfach and elsewhere. He is an editor of the International Journal of Geometric Methods in Physics, and an Honorary Member of the British Society for the Philosophy of Science.

See also: Klaas Landsman at Wikipedia (NL).

### Shoumin Liu

september 2008 - 2012.7 PhD in TU/e, with Prof Arjeh Cohen

August 2012 - present postdoc in UvA.

#### Publications

A. Cohen, S. Liu, S. Yu, Brauer *algebra of type C,
*Journal of Pure and Applied Algebra, Volume 216, Issue 2, February 2012,
Pages 407-426.

arXiv:1112.4954 *Brauer algebras of type B, *Arjeh
M. Cohen, Shoumin Liu

PhD thesis: *Brauer algebras of non-simply laced type.
*

arXiv:1206.6596 *Brauer algebra of type F4, *
Shoumin Liu

arXiv:1207.5944 *Brauer algebra of type I2n, *
Shoumin Liu

### Eduard Looijenga

Eduard Looijenga (1948) obtained his Masters's degree in mathematics at the University of Amsterdam in 1971. From 1971 till 1973 he stayed as a junior fellow at the Institut des Hautes Études Scientifiques and in 1974 he took his doctoral degree at the University of Amsterdam. After holding a postdoc position at the University of Liverpool (1974-75), he was appointed Professor at the University of Nijmegen (1975). From 1987 till 1990 he was at the University of Amsterdam and in 1991 he took his current position at the University of Utrecht. He held visiting positions at Yale (1980), U. of North Carolina at Chapel Hill (1985), Columbia U. (1987), U. of Michigan at Ann Arbor (1990), U. of Utah (1991).

His research started in singularity theory, but migrated via Torelli problems (often related to rational surfaces and K3 surfaces) to locally symmetric varieties, then to mapping class groups and moduli spaces of curves, while his recent work is concerned with automorphic forms with poles along Heegner divisors and (jointly with Heckman and Couwenberg) generalizations of Lauricella functions.

Looijenga was an invited speaker at the ICM in 1978 and at the ECM in 1992. He was on the selection panel for Algebraic Geometry of the ICM in 1994, the Prize Committee of the ECM in 2000 and the Scientific Committee of the ECM in 2004. Since 1995 he is an ordinary member of the Royal Netherlands Academy of Arts and Sciences (KNAW). He is currently editor of Comp. Math., Michigan Math. J. and the J. of the Eur. Math. Soc..

### Ieke Moerdijk

Izak (Ieke) Moerdijk (1958) studied mathematics, philosophy and general linguistics at the University of Amsterdam. He received his PhD in Mathematics from the same institution in 1985, with the distinction Cum Laude. Subsequently he worked at the University of Chicago and at the University of Cambridge, before joining the Mathematics Department of the University of Utrecht in 1988, where he has been a Professor of Topology since 1996. Moerdijk was awarded a Huygens Fellowship from NWO in 1986 and a PIONIER grant, again from NWO, in 1995. Moerdijk held visiting positions in Cambridge (St John's College), Montreal (McGill University), Sydney (University) and Aarhus, among others. He was an invited speaker at the ECM 2000.

At Utrecht, Moerdijk has successfully supervised nine PhD theses, and is supervising another three at present.

Moerdijk's current research interests include algebraic and differential topology (operads, Lie groupoids, ...), and applications of topological structures in mathematical logic. He is the coauthor of several well-known books, including "Sheaves in Logic and Geometry" with S. Mac Lane (Springer-Verlag, 1992, 1994), and "Introduction to Foliations and Lie Groupoids" with J. Mrcun (Cambridge UP, 2003). He has published over 60 research papers in refereed journals. Together with C. Berger, he recently provided a solution to the problem of the existence of homotopy model structures for operads and their algebras.

Moerdijk is editor of The Annals of Pure and Applied Logic, of The Journal of Pure and Applied Algebra, and of Theory and Applications of Categories, and is a member of the Advisory Board of North-Holland Mathematical Library.

### Ben Moonen

Ben Moonen studied mathematics at the University of Utrecht. He was a Visiting Fellow at Harvard during the first half of 1994. After receiving his PhD at the University of Utrecht in 1995, he held postdoctoral positions in Muenster and Princeton, after which he obtained a KNAW Fellowship. In 2001 he moved to the University of Amsterdam. In 2013 he was appointed as full professor of Algebra at Radboud University Nijmegen.

Moonen's main research interests lie in the domain of Arithmetic and Algebraic Geometry and include Abelian Varieties, Shimura Varieties, Moduli theory, Algebraic Cycles and Motives.

Moonen held visiting positions at Paris, Montreal and Kyoto. He has been supervisor of 3 PhD students and is currently training a fourth.

He has been organiser of various scientific activities and conferences, the most research of which was a big conference on Algebraic Geometry in Amsterdam, July 2013. He has been managing editor of Compositio Mathematica for more than 9 years.

### Michael Mueger

Michael Mueger (1965) studied physics at the Technical University Darmstadt, where he obtained his diploma in 1992. He received his PhD in mathematical physics from Hamburg University in 1997. From then until 2004 he worked as a postdoc in the mathematics departments of the universities Tor Vergata and La Sapienza (Rome), of Universite Louis Pasteur (Strasbourg), where he obtained his habilitation diriger des recherches in 2002, at the School of Mathematics of Tel Aviv University, at MSRI (Berkeley) and at the Korteweg-de Vries Institute (UvA). Since 2004 he works at Radboud University (Nijmegen), now as universitair docent in Analysis and Mathematical Physics.

Mueger's research currently focuses on category theory, low dimensional topology, quantum groups, operator algebras and rigorous quantum field theory (axiomatic, constructive, conformal, topological).

### Dietrich Notbohm

Dietrich Notbohm (1955) studied Mathematics at the Universität Göttingen, where he received his PhD in 1988 and his Habilitation in 1992. Subsequently Notbohm worked in Göttingen and Bielefeld, held visiting professorships in Münster (University) and Chicago (Northwestern University) and spend two years at the Max Planck Institute for Mathematics in Bonn, before he was appointed as lecturer at the University of Leicester. He was promoted to reader (2003) and to professor in mathematics (2005). In 2007, he moved to Amsterdam where he became professor of geometry at the Vrije Universiteit. Notbohm's research is in the area of algebraic topology and homotopy theory. In particular, he is interested in toric topology with connections to differential topology, commutative algebra, homological algebra and combinatorics, and in the homotopy theory of classifying.

### Eric Opdam

Eric M. Opdam (1960) studied mathematics at the University of Leiden. He received his PhD in Mathematics in 1988, also at the University of Leiden. He worked at the University of Utrecht and at the Massachusetts Institute of Technology before accepting a permanent position at the University of Leiden in 1989. He stayed in Leiden until 1999 when he was appointed as professor in Mathematics at the University of Amsterdam.

Opdam has held positions as a visiting professor at several occasions in Ann Arbor (MI, USA), Paris, Marseille and Kyoto. He was invited speaker at the EMC in 2000 and at the ICM in 2006. In 2000 he was awarded a prestigious Pionier grant from NWO. He has successfully supervised 2 PhD students, and he is currently training three more. In 2001 he was honorary promotor when Ian Macdonald was granted an honorary doctorate degree at the University of Amsterdam.

Opdam's research interests include representation theory, Lie groups and algebraic groups, Hecke algebras, integrable systems, special functions, and operator algebras. In his work he has paid special attention to applications of techniques across traditional borders. This has led to active contacts with researchers in various disciplines, ranging from algebraic combinatorics to Langlands philosophy.

### Dmitri Roytenberg

I started out in 1989 as a first-year student at the Department of Mathematics and Mechanics of Moscow State University. After emigrating to the United States I transferred to New York University which I finished in May 1993 with a B.A. in Mathematics (Summa Cum Laude). In August of the same year I began my graduate studies at the University of California at Berkeley under the supervision of Alan Weinstein, and completed my Ph. D. in May 1999. Since then I've worked at Penn State University, Utrecht University, IHES and MPIM. I am currently working at Utrecht and Nijmegen Universities as part of Ieke Moerdijk's research group. I live in Amsterdam.

### Dirk Siersma

Dirk Siersma (1943) studied mathematics and meteorology at the University of Amsterdam. After a teaching position at a secondary school he returned to this university , where he received a PhD in 1974. His supervisor was Nicolaas H. Kuiper. He became associate professor in Utrecht in 1976 and full professor in 1980.

Siersma's active research interest is singularity theory and applications. His principal work includes classification of singularities, geometry and topology of non-isolated singularities, behaviour of singularities at infinity and more recently the study of the conflict set of the distance function. He was one of the founding members of the Dutch Singularity School. He has approximately 30 refereed research papers and supervised 11 PhD students.

Siersma has many East-European contacts: he has been coordinator of three consecutive INTAS programs with the former Soviet union and two NWO-programs with Russia. Moreover he has been main organizor of the Singularity Semester at the Newton Institute in Cambridge (Fall 2000) and (co)organizor of many international scientific meetings in his field, e.g. in the framework of the European Singularity Network. Recently he was invited guest at IHES (2 months), Banach Center (1 month) and the University of Lille (1 month).

Siersma was the first scientific director of the Mathematical Research Institute (MRI) in The Netherlands and the initiator of its scheme of international Master Classes.

### Urs Schreiber

I received my Ph.D. in theoretical physics in 2005 from the University of Essen, Germany. Then I spent four years as a postdoc in the math. department in Hamburg in the group of Christoph Schweigert. After a few months at the Hausdorff Institute for Mathematics in Bonn, I started a postdoc position in Utrecht at the end of 2009, in the group of Ieke Moerdijk.

My research is motivated from structural questions in mathematical physics and tends to involve tools from higher category theory.

### Maarten Solleveld

Maarten Solleveld
(1979) studied mathematics at the Universiteit van Amsterdam. From 2002 till
2006 he was a PhD-student at the UvA, under the supervision of Eric Opdam. In
2007 he obtained his PhD and held short-term positions at the UvA and at the
Hausdorff Institut für Mathematik in Bonn. In september 2007 he moved to
Göttingen, where worked as a post-doc for four years. In june 2011 he received
his Habilitation from the Universität Göttingen.

Since the autumn of 2011 he is a tenure-track UD at the Radboud Universiteit
Nijmegen.

Solleveld's
research interest is in representation theory with a geometric flavour.
Recurring themes in his work are affine Hecke algebras, reductive p-adic groups,
Bruhat-Tits buildings

and noncommutative algebraic geometry.

Apart from
mathematics, Solleveld is an international master in chess. With his rating
around

2500, he ranks among the 25 best chess players of the Netherlands.

### Joseph Steenbrink

Joseph Steenbrink (1947) studied mathematics at the University of Nijmegen, where he got his degree in 1969. He received his PhD at the University of Amsterdam in 1974, where Frans Oort was his supervisor. Subsequently he spent a year at the IHES at Bures sur Yvette, invited by Pierre Deligne. He was supported by an NWO stipend. He became assistant professor at the University of Amsterdam and full professor at Leiden University in 1978. Since 1988 he has the chair in geometry at the University of Nijmegen. He supervised nine PhD students, several of whom (Van Straten, Stevens, de Jong) now are full professor. His main research interest is algebraic geometry, where he has developed tools in mixed Hodge theory and applied these to singularity theory. He was one of the leaders of the successful NWO-projects in Singularity Theory and Arithmetic Algebraic Geometry. He was invited speaker at many international events, notably at the ICM 1990 in Kyoto. He has been Managing Editor of Compositio Mathematica from 1982 till 1993, and is a member of the Advisory Boards of North-Holland Mathematical Library and Epsilon Uitgaven. He was dean of the Faculty of Mathematics and Informatics during six years, and scientific director of the Mathematical Research Institute. His current research interests are: geometry of moduli spaces and of certain special threefolds. He published 50 research papers in refereed journals.

### Jan Stienstra

Jan Stienstra's research interests:

Relations between the
theory of motives and string theory. This includes, in concreto,
research on toric geometry/GKZ hypergeometric systems/mirror symmetry,
Picard-Fuchs equations/crystalline cohomology/large complex structure
limit, Mahler measure/L-functions/melting crystals/dimer models.

### Walter van Suijlekom

Walter D. van Suijlekom studied Theoretical Physics at the University of Amsterdam from 1996 to 2001, and wrote his master's thesis under supervision of drs. G.G.A. Bauerle. After a year of Mathematics at the University of Amsterdam, he was a guest-researcher in the group of Prof. dr. N. P. Landsman at the Korteweg-de Vries Institute for Mathematics. In 2005, van Suijlekom obtained his PhD-degree at the International School for Advanced Studies (SISSA) in Trieste, Italy, under supervision of Prof. L. Dabrowski and Prof. G. Landi.

From November 2005 until December 2006, van Suijlekom is a postdoc at the Max Planck Institute for Mathematics in Bonn, Germany. In January 2007, he will start as a postdoc at the IMAPP in Nijmegen, the Netherlands.

Van Suijlekom's field of research is noncommutative geometry; his work concentrates at its interaction with quantum group theory as well as its applications to quantum Yang-Mills gauge theories.

### Roland van der Veen

After getting his PhD with Eric Opdam in Amsterdam, Roland van der Veen was a NWO Rubicon post-doc with Nicolai Reshetikhin at UC Berkeley. Recently Roland was awarded an NWO Veni award, allowing him to continue his research on low-dimensional topology/geometry, representation theory and mathematical physics at the University of Amsterdam.

### Fabian Ziltener

Fabian Ziltener
received his Ph.D. from ETH Zurich in 2006. Subsequently he was a postdoc at LMU
(the Ludwig Maximilian University of Munich), supported by a fellowship of the
Swiss National Science Foundation. This was followed by a postdoc position at
the University of Toronto and an assistant professorship at KIAS, the Korea
Institute for Advanced Study, where he received the ``award of excellence'' in
2012. After an intermezzo as a substitute associate professor at LMU, in 2013 he
was appointed as universitair docent (assistant professor, permanent position)
at Utrecht University.

Ziltener's research area is symplectic geometry. For certain coisotropic
submanifolds of symplectic manifolds he has proved a lower bound on the number
of leafwise fixed points of a given Hamiltonian diffeomorphism. Examples of
applications are a symplectic nonsqueezing result and the existence of stably
exotic symplectic structures. In another part of his research he has
investigated the symplectic vortex equations. These are a gauge theoretic
version of the Cauchy-Riemann equation. They are related to the Gromov-Witten
invariants of symplectic quotients.