Workshop on Nonlinear Algebra

TU Berlin, March 26-27, 2020

Postponed due to Coronavirus

We regret to announce that the workshop has been postponed indefinitely.
The TU Berlin has taken the official decision to cancel all events until July 2020 in an attempt to minimise the spread of the Corona Virus. You can find more information on the TU's policy here.


This workshop celebrates the accomplishments of the Einstein project that started in April 2015 and ends in July 2020. The original proposal centered around 20 concrete problems that were organized into four themes: maximum likelihood geometry, euclidean distance optimization, convex algebraic geometry, and classical moduli spaces. More than half of the 20 problems have since been solved. The problems and their solutions will be featured in the one-hour lectures, while the shorter lectures present recent research results on other topics in Nonlinear Algebra.
The support of the Einstein Foundation and MPI for Mathematics in the Sciences in Leipzig is gratefully acknowledged.



The titles and abstracts can be found here.

Thursday, March 26th
09:00-09:20 Registration
09:20 - 09:30 Welcome
09:30 - 10:30 Kaie Kubjas (Aalto University) Nonnegative rank
10:30 - 11:00 Coffee Break
11:00 - 11:30 Benjamin Schröter (Binghamton University) Tropical Grassmannians and Dressians
11:30 - 12:30 Diego Cifuentes (MIT) The geometry of SDP relaxations
12:30 - 14:00 Lunch
14:00 - 14:30 Carlos Améndola (TU Munich) Invariant Theory and Iterative Proportional Scaling
14:30 - 15:00 Fatemeh Mohammadi (Ghent University / UiT Tromsø) Conditional Independence Models
15:00 - 15:30 Coffee Break
15:30 - 16:30 Jose Israel Rodriguez (University of Wisconsin - Madison) Nearest point problems
16:30 - 17:00 Sascha Timme (TU Berlin) Estimating linear covariance models
19:00 Social Dinner*

Friday, March 27th
09:30 - 10:30 Marta Panizzut (TU Berlin) Moduli space of tropical cubic surfaces
10:30 - 11:00 Coffee Break
11:00 - 11:30 Kathlén Kohn (KTH Stockholm) Minimal Problems in Computer Vision
11:30 - 12:30 Emre Sertöz (MPI MiS Leipzig) Developing a calculus for periods of varieties
12:30 - 14:00 Lunch
14:00 - 14:30 Alheydis Geiger (Universität Tübingen) A tropical count of binodal cubic surfaces
14:30 - 15:00 Ben Smith (University of Manchester) Face posets of tropical polyhedra
15:00 - 15:30 Coffee Break
15:30 - 16:30 Bernd Sturmfels (UC Berkeley / MPI Leipzig) Theta surfaces


If you plan to attend this workshop, please register by sending an e-mail to Antje Schulz (
To help us smooth out the organization, please use the subject line 'Registration NLA' for your e-mail.


All the talks will be held in room MA 042 in the Institute of Mathematics at TU Berlin. The coffee breaks will take place in room MA 141.
*The social dinner will be self paid.