News
Spring 2023: I'm organising the SMG Spring Meeting. Please attend!
Fall 2022: I'll be on sabbatical at the IAS as a participant in the Special Year on Dynamics, Additive Number Theory and Algebraic Geometry.

January 2022: I have succeeded Bernd Sturmfels as Editor-in-Chief of the SIAM Journal on Applied Algebra and Geometry.

Dec 2020: my former Ph.D. student Arthur Bik as won an SNF Postdoc.Mobility grant, with which he will spend a year at MPI MIS (Leipzig) and a year at Texas A&M (College Station). Congrats to Arthur!

Nov 2020: my Ph.D. student Alejandro Vargas won an SNF Early Postdoc.Mobility grant, with which he will spend time in Frankfurt and Nantes. Congrats to Alejandro!

Feb 2020: We have created a movie visualising parts of my joint paper with Alejandro Vargas on the gonality of metric graphs.

Feb 2020: Shreehari Bodas, a Bachelor's student from IIT Bombay, has successfully applied for a ThinkSwiss 2020 Research Scholarship to visit my group for two months this summer---unfortunately, due to the Covid-19 pandemic, his visit did not take place.

Apr 2019: The current, online version of the programme for SIAM AG 19 is online.

Mar 2019: My paper on topological Noetherianity of polynomial functors was accepted for publication in the Journal of the AMS.

July 2018: My former student Rob Eggermont has won a Veni grant.

June 2018: The website for MEGA 2019 is up and running.

Apr 2018: The website for SIAM AG 19 is up and running.

Dec 2017: My student Arthur Bik won the DIAMANT prize for best Ph.D. talk at the DIAMANT symposium; see this picture.

Nov 2017: MEGA (Effective Methods in Algebraic Geometry) now has a permanent website collecting information about past and future MEGAs!

May 2017: Christandl, Jensen, and Zuiddam give very simple and elegant examples of strict submultiplicativity of tensor rank under the tensor product in this preprint!

Jan 2017: Paul Breiding has succeeded at evaluating our formula for the average ED degree of the cone over Veronese embeddings. See Paul's impressive preprint and our paper for the formula.

Jan 2017: Andries Brouwer and Dan Christensen refuted the Gale-Neyman conjecture that in chomp on the n-dimensional hypercube {0,1}^n with poisoned block at the origin, the all-one vector is a winning first move. They show this is not true for n=7. See this page.

Aug 2016: I have moved to the Bern math institute, succeeding Christine Riedtmann.

Mar 2016: Anna Seigal wrote a blog about the pictures on the cover of our new SIAM journal.

Feb 2016: My Vici proposal entitled Stabilisation in Algebra and Geometry was successful!

Feb 2016: The website for the journal is up, and paper submission will open on 23 March.

Jan 2016: Here is the cover art for the new SIAM Journal on Applied Algebra and Geometry---the website will be up soon!


Dec 2015: Our proposal for a new SIAM Journal on Applied Algebra and Geometry was approved by SIAM. We aim to attract the best papers in this broad area. Submission will open soon, but please contact me if you have fantastic work that could fit!

June 2015: the Mittag-Leffler proposal by Anders Jensen, Hannah Markwig, Benjamin Nill, and myself for a semester on Tropical geometry, amoebas, and polytopes was accepted for Spring 2018!

May 2015: Rob Eggermont got his Ph.D. with the distinction cum laude; congratulations! See this news item.

April 2015: My article on Plücker varieties with Rob Eggermont was accepted by Crelle's journal.

April 2015: I have joined the editorial boards of Linear and Multilinear Algebra, Nieuw Archief voor Wiskunde and, last year, of Experimental Mathematics. Where appropriate, please consider submitting your work to one of these journals.

March 2015: I wrote a SIAM News article loosely based on lectures by Peter Bürgisser and others during the Simons Institute semester on Algorithms and Complexity in Algebraic Geometry.

January 2015: I was appointed parttime full professor at the VU Amsterdam; see this news item.

October 2014: Rekha Thomas wrote a beautiful article for SIAM News on the Euclidean distance degree.

Fall 2014: The MEGA 2015 website is in place, and submission of papers, extended abstracts, computations, and posters is open!

October 2014: both my last-year's Master students have started Ph.D.'s: Jasmijn Baaijens in the CWI life sciences group, under the supervision of Alexander Schönhuth; and Guus Bollen in Discrete Maths here at TU/e, under the supervision of Hans Cuypers, Rudi Pendavingh, and myself. The best of luck to both!

September 2014: The conference website for the SIAM Conference on Applied Algebraic Geometry is up and running. Check it out, and consider organising a minisymposium! The conference has also been accepted as a ICIAM 2015 satellite.

July 2014: my Department nominated me for a TU/e Education Award, as their candidate in the category Best Master's Program Lecturer.

Spring 2014: three members of the SIAM (AG)^2 were elected SIAM fellows: Jean Lasserre, Peter Olver, and Bernd Sturmfels. Congratulations!

24 February 2014: I wrote a guest post on Rota's basis conjecture for The Matroid Union.

9 January 2014: I won the GEWIS teaching award 2013/2014 for Mathematics. Needless to say, I'm very, very proud of this!

December 2013: I was elected Chair of the SIAM activity group on Algebraic Geometry. This group brings together researchers who use algebraic geometry in industrial and applied mathematics. If you are an algebraic geometer interested in applications, or if you have a maths/statistics/engineering/CS/... problem that you think might benefit from algebraic techniques, please check out this activity group (or contact me). It's this interplay that makes the group such a success!

24 October 2013: my paper with Eggermont on the existence of poly-time membership tests for a wide class of phylogenetic models has just been accepted for J. Eur. Math. Soc.

1 May 2013: my paper with Kuhnt and Zwiernik on groups acting on Gaussian graphical models has just been accepted for Annals of Statistics.

Spring 2013: Robert Krone from GeorgiaTech is visiting for three months. Together with Anton Leykin and Rob Eggermont we aim to prove finiteness-up-to-symmetry results for certain infinite-dimensional toric varieties.

15 October 2012: the website of the CIME/CIRM course Combinatorial Algebraic Geometry, taking place from 10-15 June 2013 in Levico Terme, is up. Check it out!

1 September 2012: Emil Horobeţ from Babes-Bolyai university joins the group on the project Tensors of Bounded Rank.

23 January 2012: Tensors of Bounded Rank, an NWO free competition Ph.D. project proposal together with Monique Laurent and Siep Weiland has been awarded funding!

23 January 2012: Piotr Zwiernik is starting a Post-doc in the Vidi project.

1 September 2011: Rob Eggermont started his Ph.D. in the Vidi project.

2 March 2011: a manuscript with Johan P. de Jong on his Bachelor's project has been accepted for publication in the EMS Newsletter. See this page.

6 October 2010: A Vidi grant! See this page or this page or this page.

Talks/slides

Well-quasi-orders and algebra, Combinatorial Coworkspace, Haus Bergkranz, March 2024.

Why we decompose tensors, invited talk at SIAM AG 23, Eindhoven, July 2023.

Amoeba dimensions, New Directions in Real Algebraic Geometry, Oberwolfach, March 2023.

New instances of equivariant Noetherianity, Fellowship of the ring, March 2023.

A tensor restriction theorem over finite fields, Texas A&M University, December 2022.

A tensor restriction theorem over finite fields, Tensors: Quantum Information, Complexity and Combinatorics, CRM Montreal, November 2022.

The geometry of polynomial functors, University of Alberta Algebra Seminar, Edmonton, November 2022.

On tensors properties preserved under linear maps, Workshop on Additive Combinatorics and Algebraic Connections, Institute for Advanced Study, November 2022.

Noetherianity up to Symmetry, Members' colloquium, Institute for Advanced Study, October 2022.

On the work of June Huh, Swiss Mathematical Society Fields Medal Day, Bern, October 2022.

The geometry of polynomial functors, Princeton Algebraic Geometry Seminar, September 2022.

Fewestnomials in determinantal ideals, Combinatorial, Computational, and Applied Algebraic Geometry, Seattle, June 2022.

GL-varieties, minicourse at 155 Years of Commutative Algebra, Osnabrück, June 2022.

Implicitisation and parameterisation for polynomial functors, Workshop on geometry and complexity theory, Toulouse, April 2022.

No short polynomials vanish on bounded-rank matrices, Konstanz Real Geometry and Algebra seminar, January 2022.

The geometry of polynomial representations, at the Oberwolfach-RIMS tandem workshop on Symmetries on polynomial ideals and varieties, September 2021.

Introduction to the minisymposium on structured tensors, at SIAM Conference on Applied Algebra and Geometry, August 2021.

Algebra over FI, Nonlinear Algebra Seminar Online (NASO), January 2021.

Algebra over FI, DIAMANT symposium, The Netherlands, November 2020.

The geometry of polynomial functors, Seminario di Algebra & Geometria, Rome, November 2020.

Catalan-many morphisms to trees, part I, at Tropical Geometry in Frankfurt (via Zoom) , April 2020.

Matroids: algebraicity, duality, and valuations, an invited talk at Network Games, Tropical Geometry, and Quantum Communication, Berlin, June 2019.

A short history of strength, an invited talk at Advances in applied algebraic geometry, Bristol, 14 December 2018.

Polynomial functors: Noetherianity and Applications, a three-hour minicourse as part of the Michigan representation stability week, August 2018; and some exercises/questions.

Trek combinatorics and partial correlation hypersurfaces, at the summer school Graphical Models: From Mathematical Foundations to Biological Applications, ETH, Basel, June 2018.

Finiteness for polynomial functors, Algebra and Geometry seminar, KTH, 31 January 2018.

Tropical aspects of algebraic matroids, Institut Mittag-Leffler, Workshop on Tropical algebra and applications, 22-26 January 2018.

(Some/What is) algebraic statistics, Algebraic methods in statistics, Osnabrück, 30 November-2 December 2017.

Graphical models and their equations, Workshop on algebraic statistics, Montpellier, 16 November 2017.

Algebraic matroids and Frobenius flocks, Matroids over Hyperfields, Fribourg, 28 August 2017.

Best rank-k approximations to tensors, SIAM Conference on Applied Algebraic Geometry, Atlanta, 2 August 2017.

Finiteness for polynomial functors, Dortmund, 22 June 2017.

Finiteness for polynomial functors, Eindhoven discrete math seminar, 14 June 2017.

Finiteness for polynomial functors, Neuchâtel maths colloquium, 16 May 2017.

Stabilisation in Algebra and Geometry, Fribour maths colloquium, 21 March 2017.

Orthogonal tensor decomposition from an algebraic perspective, Basel Algebra Seminar, 3 March 2017.

Frobenius Flocks, PEAKS 17, Riezlern, February 2017.

Orthogonal tensor decomposition from an algebraic perspective, Colloquium, Konstanz, November 2016.

Maximum likelihood geometry, Statistics colloquium, Bern, October 2016.

(Uniform) determinantal representations, Geometry seminar, Firenze, October 2016.

(Uniform) determinantal representations, Kolloquium, Bern, October 2016.

Stabilisation in algebra, geometry, and combinatorics, SIAM Conference on Discrete Mathematics, Atlanta, June 2016.

Stabilisation in algebraic statistics, Free Resolutions, Representations, and Asymptotic Algebra, Banff, 7 April 2016. The slides contain more information than the board talk, of which a video can be found here.

Orthogonally decomposable tensors as semisimple algebras, Intercity Seminar Number Theory, VU Amsterdam, 6 November 2015.

Metric graphs with prescribed gonality, SIAM Conference on Applied Algebraic Geometry, Daejeon, 3-7 August 2015.

Singular Landscapes, a conference in honour of Bernard Teissier's 70th birthday, invited speaker, 22-26 June 2015.

Artin approximation and infinite dimensional geometry, CIRM Luminy, invited speaker, 23-27 2015.

Gossip and the composition of metrics, Eindhoven Discrete Math Seminar, 26 November 2014.

Counting critical rank-one approximations to tensors, workshop on Tensors in Computer Science and Geometry, Simons Institute, 10 November 2014.

Energy minimisation on a toric grid, Berkeley combinatorics seminar, 15 September 2014.

Plücker varieties and higher secants of Sato's Grassmannian, Simons Institute Programme seminar, 10 September 2014.

Algorithms and Complexity in Algebraic Geometry, long-term participant at the Simons Institute for the Theory of Computing, Berkeley, Fall 2014.

Symmetries and infinite-dimensional limits of algebro-statistical models, Prague Stochastics 2014, 25 August 2014.

The Euclidean distance degree of an algebraic variety, conference in honour of Hanspeter Kraft, 3 June 2014.

The algebra of symmetric high-dimensional data, Maths colloquium at Cologne, 9 May 2014.

Torus actions and faithful tropicalisation, algebra seminar at GeorgiaTech, 11 April 2014.

The algebra of symmetric high-dimensional data, Maths colloquium at GeorgiaTech, 10 April 2014.

Specialization of Linear Series for Algebraic and Tropical Curves, participant in this Banff workshop, 30 March-4 April, 2014.

Tropische meetkunde, invited talk at Nijmegen students' conference In perspectief: hoeken van de meetkunde, 21 March 2014.

Higher secants of Sato's Grassmannian, Trento, 10 March 2014.

The algebra of symmetric high-dimensional data, maths colloquium VU Amsterdam, 5 March 2014.

The commutative algebra of highly symmetric data, Colloquium Utrecht, 21 November 2013.

Finiteness for Plücker varieties, Basel, 15 November 2013.

Higher secants of Sato's Grassmannian, MPI Bonn, 29 October 2013.

The commutative algebra of highly symmetric data, Basel, 4 October 2013.

Higher secants of Sato's Grassmannian, SIAM conference on applied algebraic geometry, Fort Collins, 2 August 2013.

Maximum-likelihood duality for determinantal varieties, Basel, 19 April 2013.

Maximum-likelihood duality for determinantal varieties, TU Eindhoven, 27 March 2013.

Finite up to symmetry, IST Austria, 28 January 2013.

Finite up to symmetry, Math. Kolloquium Osnabrück, 23 January 2013.

Energy minimisation on a toric, DIAMANT symposium, Doorn, 29 November 2012.

Maximum likelihood duality for determinantal varieties, Intercity Seminar Number Theory, Eindhoven, 2 November 2012.

Infinite-dimensional systems of polynomial equations with symmetry, a three-hour minicourse at the workshop Tensors and their Geometry in High Dimensions, UC Berkeley, 26-29 September, 2012: slides for day 1, slides for day 2, slides for day 3.

Finite up to symmetry, mathematics colloquium Frankfurt,29 June 2012.

Bounded-rank tensors and group-based models, Algebraic Statistics in the Alleghenies at The Pennsylvania State University, 8-15 June 2012.

Bounded-rank tensors, 3 May 2012, SFB Colloquium talk in Mainz.

Energy minimisation on a toric Checkerboard, 3 May 2012, Colloquium talk in Mainz.

Tensors of bounded rank, Dutch Mathematical Congress, 12 April 2012, Eindhoven

On min-plus products of distance matrices, Tropical geometry at ICMS, Edinburgh, 2-6 April 2012.

Tropical reparameterisations, Tropical geometry workshop at Castro Urdiales, December 2011.

Tropical reparameterisations, SIAM Conference Applications of Algebraic Geometry, NCSU, October 2011. Session on tropical geometry organised by Josephine Yu.

Pentads and Minors define the Gaussian two-factor model, SIAM Conference Applications of Algebraic Geometry, NCSU, October 2011. Session on algebraic statistics organised by Matthias Drton.

A tropical approach to secant dimensions, SIAM Conference Applications of Algebraic Geometry, NCSU, October 2011. Session on tensor rank organised by Lek-Heng Lim.

Bounded-rank tensors and group-based models, 27 September 2011, Saarbrücken conference on tropical geometry and computational biology.

Brill-Noether and gonality, 16 September 2011, Trento workshop on toric and tropical geometry.

On Castryck and Cools's gonality conjecture, 29 July 2011, 4th Ph.D. students conference on tropical geometry, Kaiserslautern.

An introduction to tropical geometry, 18-22 July 2011, ACAGM summer school, Leuven. Together with Filip Cools (but the notes contain only my half of the lectures).

Tropical Brill-Noether theory, 5 July 2011, Tropical Geometry and Integrably Systems, Glasgow.

Tropical Brill-Noether theory, 10 June 2011, Meeting of the Swedish Mathematical Society.

Introduction to tropical geometry, Colloquium talk at the Graduiertenkolleg Experimentelle und konstruktive algebra, 8 April, RWTH Aachen.

Tropical Brill-Noether theory, 17 March 2011, Warwick tropical day.

Finiteness results for infinite-dimensional varieties with many symmetries, 16 March 2011, Warwick algebraic geometry seminar.

Finiteness results for infinite-dimensional varieties with many symmetries, 20 January 2011, Mittag-Leffler semester on Algebraic Geometry with a View Towards Applications.

Finiteness results in statistics using algebra, 4 November 2010, stafcolloquium University of Leiden.

Finiteness results in statistics using algebra, 3 November 2010, stafcolloquium University of Amsterdam.

Finiteness results for infinite-dimensional varieties with many symmetries, 29 September 2010, IPAM workshop Convex Optimization and Algebraic Geometry, UCLA.

A tropical proof of the Brill-Noether Theorem, 28 May 2010, Arbeitsgemeinschaft Algebra und Topologie, Basel.

A tropical proof of the Brill-Noether Theorem, 19 March 2010, Intercity Number Theory Seminar, Groningen.

Constructing Lie algebras from extremal elements, 18 March 2010, Groups, Algebras and Algorithms, TU/e.

Algebro-geometric problems arising from statistics, 16 March 2010, colloquium talk, Groningen.

Trek separation for Gaussian graphical models, 3 March 2010, informal meeting Eindhoven statisticians and probabilists, TU/e.

Small maximal spaces of non-invertible symmetries, 1 February 2010, working group algebra and combinatorics, CWI.

Tropical reparameterisations, 18 September 2009, Tropical Geometry Seminar, MSRI.

Finiteness of the k-factor model, 11 September 2009, Geometry Seminar, Texas A & M.

On a theorem by Yu and Yuster, 11 September 2009, Texas A & M.

Tropical reparameterisations, 18 July 2009, Saturday in discrete mathematics, Erlangen.

Noetherian modulo a group action?, 15 June 2009, opening lecture at MEGA 2009, Barcelona.

Finiteness of the k-factor model, 14 April 2009, Dutch Mathematical Congress, minisymposium on Algebra.

New results on tensor ranks, 27 March 2009, CWI, working group PNA 1.

Finiteness of the k-factor model, 6 March 2009, CWI, working group PNA 1.

Set-theoretic finiteness for the k-factor model, 20 January 2009, Colloquium, Bremen.

Finite generation of symmetric ideals, 20 January, Precolloquium, Bremen.

Around Minkowski's 3^d-1 theorem, 14 January 2009, Seminar Combinatorial Theory, Eindhoven.

On the ideals of phylogenetic tree models, 29 November 2008, Representation theory days, ETH Zürich.

Set-theoretic finiteness for the k-factor model, 25 November 2008, AG Algebra, Basel.

Tropical reparameterisations, 12 November 2008, Bernd Sturmfels' Clifford Lectures, Tulane University, New Orleans.

Set-theoretic finiteness for the k-factor model, 15 October 2008, Seminar Combinatorial Theory, Eindhoven.

Tropical reparameterisations, 3 October 2008, INdAM workshop on Geometry of Projective varieties, Rome.

Set-theoretic finiteness for the k-factor model, 23 September 2008, Ann Arbor.

Tropical Algebraic Groups, 9 July 2008, Göttingen.

Finite generation of symmetric ideals, 4 June 2008, Eindhoven.

Phylogenetic tree models and classical invariant theory, 14 March 2008, Van der Kallen Celebration, Utrecht.

On the ideals of phylogenetic tree models, 6 February, Eindhoven.

The tropical geometry of algebraic groups, minimal orbits, and secant varieties, December 2007, Workshop on Tropical Geometry, Oberwolfach.

Tropical geometry I and II, October and November 2007, two introductory lectures, Eindhoven.

Tropical geometry, secant varieties, and multivariate interpolation, 17 October 2007, ESF exploratory workshop on polynomial interpolation, secant varieties, and applications, 16-19 October, Sestri Levante.

Tropical geometry: foundations, applications, and phenomena, July 2007, minicourse in Glanon.

A tropical approach to secant dimensions, 24 April 2007, Genoa.

Tropical geometry: foundations, applications, and phenomena, 20 April 2007, MariusFest, Groningen.

A tropical approach to secant dimensions, 30 March 2007, Tropical mini-meeting, Madrid.

A tropical approach to secant varieties, 23 January 2007, Seminar Sophus Lie, Darmstadt.

A scenic tour in tropical geometry, 9 January 2007, MAP 2007, Leiden.

A tropical approach to secant varieties, 6 December 2006, Géométrie et Représentations, Luminy.

A DIAMANT challenge, 30 November 2006, DIAMANT/EIDMA Symposium, Vught.

Classical theory of Lie algebras, 27 October 2006, DIAMANT Intercity Seminar on Lie algebras, Eindhoven.

The inverse problem of tensorial invariant theory, 13 September 2006, EIDMA Seminar Combinatorial Theory, Eindhoven.

On the Casas-Alvero conjecture, 14 June 2006, EIDMA Seminar Combinatorial Theory, Eindhoven.

A tropical approach to secant varieties, 12 May 2006, Leicester.

A tropical approach to secant varieties, 15 February 2006, EIDMA Seminar Combinatorial Theory, Eindhoven.

Polarisation in Invariant Theory, 23 November 2005, EIDMA Seminar Combinatorial Theory, Eindhoven.

Small maximal spaces of non-invertible matrices, 26 July 2005, Workshop on Lie Algebras, their Classification and Applications University of Trento, 25 - 27 July 2005.

Counting components of the null-cone on tuples, 31 May 2005, MEGA 2005, Porto Conte, Alghero, Sardinia (Italy) May 27th - June 1st 2005.

On a theorem of Gerstenhaber, 4 May 2005, EIDMA Combinatorial Theory Seminar, Eindhoven.

Counting components of the null-cone on tuples, 4 February 2005, AG Algebra, Basel.