Home page of Marcel de Jeu
|E-mail address:||Remove `NOBOTSHALLUSETHIS' from mdejeuNOBOTSHALLUSETHIS@math.leidenuniv.nl
P.O. Box 9512
2300 RA Leiden
||Niels Bohrweg 1
2333 CA Leiden
|Office telephone number:
||+31 71 527 7118
|General telephone number:
||+31 71 527 7111
|General fax number:
||+31 71 527 7101
- Guest appointment at Delft University of Technology (Delft, the Netherlands)
- Adjunct visiting professor at the University of Mississippi (Oxford, Mississippi, USA)
- Extraordinary professor at the University of Pretoria (Pretoria, South Africa)
Current research interests
- Representation theory and abstract harmonic analysis, in particular in an ordered context
- Ordered vector spaces and algebras
- Banach algebras and operator algebras
- Christian Svensson (2009, thesis)
- Marten Wortel (2012, thesis)
- Miek Messerschmidt (2013, thesis; funded by NWO)
- Rui Xie (September 2013 - August 2014, visiting PhD student from Harbin Institute of Technology; funded by CSC)
- Xingni Jiang (2018, thesis; funded by CSC)
- Yang Deng (2021, thesis; funded by CSC)
- Walt van Amstel (expected 2023; University of Pretoria; joint with main adviser Jan Harm van der Walt)
- Chun Ding (expected 2023; joint with Onno van Gaans; funded by CSC)
I am an editor of Annals of Functional Analysis and of Positivity.
Since 2001, I have always uploaded my papers, including a final version with the text as published, to
. The list in MathSciNet (use this link when you are at the Leiden campus) also contains my older papers, but it can be lagging considerably for the newer ones.
The Leiden Repository contains a number of my papers as published.
My ORCID iD is 0000-0002-7295-8969.
I am the chairman of the steering committee for the biyearly Positivity conferences. Please feel free to contact me for all matters concerned.
The Positivity webinar started in March 2021. All relevant information can be found here.
I am the chairman of the library committee of the Mathematical Institute and of that of the Faculty of Science. If you are a member of the academic community of the Faculty of Science, please feel free to contact me concerning all library matters, including suggestions for new acquisitions.
Past and upcoming events
Summer School on Noncommutative integration, Leiden, 9 - 13 June 2008.
Workshop Operator structures and dynamical systems, Leiden, 21 - 25 July 2008 (satellite of 5 ECM). The proceedings appeared in 2009 in the Contemporary Mathematics series of the AMS.
- The SIGMA Special issue on Dunkl operators and related topics, for which I was one of the guest editors, was completed in June 2009.
- The Positivity VII conference was held from 22 - 26 July 2013 at the campus of Leiden Universityl, jointly organised by Leiden University and Delft University of Technology. I served as chairman on the organization committee of this Zaanen Centennial Conference, on the occasion of the 100th birthyear of Adriaan Cornelis Zaanen (1913 - 2003). Edited by Onno van Gaans, Ben de Pagter, Mark Veraar, and myself, the proceedings appeared with Birkhäuser in 2016.
- Tony Wickstead and I were the main organisers, together with Garth Dales, Sonja Mouton, and Ben de Pagter, of the Ordered Banach algebra workshop at the Lorentz Center in Leiden, from 21 - 25 July 2014. Tony Wicksteade and I were also the editors of a special issue on ordered Banach algebras of Positivity on the subject that appeared in 2017. It also contains a list of open problems that was compiled by Tony Wickstead, and an obituary for Egor Alekhno, who was one of the participants. On the ocassion of the workshop, Tony Wickead, Sonja Mouton, and I compiled a bibliography on ordered Banach algebras that we believed to be reasonably complete at the time.
Positivity VIII was held in Chengdu from 20 - 24 July 2015.
Positivity IX was held in Edmonton from 17 - 21 July 2017.
- In October 2017, Garth Dales was my guest as that year's Kloosterman Professor.
- A workshop on operator algebras and harmonic analysis was held at the Tsinghua Sanya International Mathematics Forum from 18 - 22 December 2017.
- There was a BIRS workshop on recent advances on Banach lattices in Oaxaca, Mexico, from 29 April - 4 May 2018.
- From 26 - 28 September 2018, Jan van Neerven and I organised a workshop `Positivity and noncommutative analysis' in Delft on the occasion of the 65th birthday of Ben de Pagter. A Festschrift for Ben de Pagter, of which I am one of the editors, was also initiated. It has appeared with Birkhäuser in 2019.
Positivity X was held in Pretoria from 8 - 12 July 2019.
- Conference on Conference on Ordered Structures with Applications in Economy and Finance, 3-7 May 2021, online.
Positivity XI, originally scheduled in July 2021, will now take place from 10-14 July 2023. It will still be in Ljubljana, Slovenia.
Functional analysis seminar
We have a series of yearly functional analysis seminars in the spring semester, for faculty, PhD students, and advanced MSc students
- In the 2005 seminar we concentrated on spectral theory and operator algebras.
- The 2006 seminar was about Banach space theory.
- In the 2007 seminar the emphasis was on operator theory.
- In 2007 - 2008 we covered most of the book by Albiac and Kalton on Banach space theory.
- In 2008 - 2009 was devoted to Meyer-Nieberg's book on Banach lattices; the twin seminar in Delft was on noncommutative probability.
- In 2009 - 2010 the seminar was based on Kaniuth's `A course in commutative Banach algebras'.
- In 2010 - 2011 we used Engel's and Nagel's `A short course on operator semigroups'.
- In fall 2011 a joint Leiden/Delft seminar was dedicated to Choquet theory, based on Phelps' book.
- In spring 2012, Ryan's `Introduction to tensor products of Banach spaces' was used.
- In fall 2012, Miek Messerschmidt ran a seminar on `Cones and duality' by Aliprantis and Tourky.
- In spring 2013, Onno van Gaans ran a seminar on `An invitation to operator theory' by Abramovich and Aliprantis.
- In spring 2014, Onno van Gaans ran a seminar on the geometry of Banach spaces.
- In spring 2015, Onno van Gaans and I organised a seminar on concrete examples of Banach lattices and their (regular) operators.
- In spring 2016, Sander Hille, Onno van Gaans, and I organised a seminar on spaces of measures.
- In spring 2017, Onno van Gaans and I organised a seminar on partially ordered vector spaces and their operators.
- In spring 2018, Onno van Gaans and I organised a seminar on abstract harmonic analysis.
- In spring 2019, Onno van Gaans and I organised a seminar on Banach space theory.
- In spring 2020, Bram Mesland, Onno van Gaans, and I organised a seminar on operator spaces that had to be discontinued because of covid.
- In spring 2021, there was no seminar because of covid.
- In fall 2021, Bram Mesland, Jan Harm van der Walt, and I organised a seminar on completely bounded maps and operator algebras.
- In spring 2022, Bram Mesland, Onno van Gaans, and I organise a seminar on JB- and JBW-algebras. Our mathematical guides are Mark Roelands and Marten Wortel.
Teaching fall 2021
Onno van Gaans and I are the lecturers of the (on campus again) national Mastermath course in Functional Analysis. We use Conway's `A course in functional analysis'.
Teaching spring 2022
Floske Spieksma and I are the organisers of the bachelor seminar on Analysis, Stochastics, and Optimisation.