Institute
General information about the institute, such as our mission statement, organizational structure, staff directory, history, directions, etc.

See More
Research
Scientific profile with all research groups, topics, collaborations, as well as columns on research at the institute.

See More
News
News and press releases about the institute, as well as a media archive.

See More
- News Overview
- Press Releases
Events
Overview of all events around the institute, such as talks, seminars, lectures, workshops, conferences and public events.

See More
Publications
Overview of all scientific publications of the institute, as well as our preprint and software repositories.

See More
Career
Information on open positions at the institute, benefits of working with us, graduate school, and postdoctoral supervision.

See More

Events
Leipzig-Magdeburg seminar day

MPI für Mathematik in den Naturwissenschaften Leipzig

E1 05 (Leibniz-Saal)

conference

09.08.22

Leipzig-Magdeburg seminar day

The purpose of this event is to reconnect the algebra groups at the University of Magdeburg and the MPI Leipzig through a day of talks (half Leipzig, half Magdeburg) and scientific discussion about recent or ongoing research.

Program

09:25 - 09:30	Opening Remarks
09:30 - 10:30	Alessandro Neri (Max Planck Institute for Mathematics in the Sciences) Linear Sperner families and strong blocking sets in coding theory Minimal linear codes were first introduced by Cohen and Lempel over the binary field under the name of linear intersecting codes. They later gained interest due to their application to secret sharing schemes proposed by Massey. Concretely, minimal linear codes are subspaces of vectors over a finite field such that the set of nonempty supports forms an antichain with respect to the set inclusion. In other words, they provide the vector space analogue of Sperner families. Recently, it has been shown that minimal linear codes in are in one-to-one correspondence with strong blocking sets, which are special sets of points in a projective space, such that their intersection with each hyperplane generates the hyperplane itself. In this talk we will revise the basic theory connecting these three objects with combinatorial, algebraic and geometric flavours: linear Sperner families, minimal linear codes and strong blocking sets. We will show first properties and bounds on their cardinality and parameters. Later, we will go through some classical constructions mainly obtained as union of lines. If time allows, we will then explore new ideas for constructing strong blocking sets over any field, obtained as union of rational normal curves.
10:30 - 10:45	Break
10:45 - 11:45	Volker Kaibel (OVGU Magdeburg) Taming Polytopes by Lifting We cover some aspects of the theory of extended formulations, i.e., representations of polytopes that appear wild in one or the other sense as projections of higher-dimensional ones that are much tamer. Our selection of topics is biased towards parts of the work done in our own research group, where the lecture will close with a recent result related to the Hirsch-conjecture on the diameter of polytopes obtained jointly with Kirill Kukharenko.
11:45 - 12:30	Meet the math
12:30 - 14:00	Lunch
14:00 - 15:00	Julia Lindberg (Max Planck Institute for Mathematics in the Sciences) Estimating Gaussian mixtures using sparse polynomial moment systems The method of moments is a statistical technique for density estimation that solves a system of moment equations to estimate the parameters of an unknown distribution. A fundamental question critical to understanding identifiability asks how many moment equations are needed to get finitely many solutions and how many solutions there are. We answer this question for classes of Gaussian mixture models using the tools of polyhedral geometry. Using these results, we present a homotopy method to perform parameter recovery, and therefore density estimation, for high dimensional Gaussian mixture models. The number of paths tracked in our method scales linearly in the dimension.
15:00 - 15:15	Break
15:15 - 16:15	Xiangying Chen (OvGU Magdeburg) The geometry of conditional independence structures and their Coxeter friends A conditional independence structure consists of triples (ij\|K) which can be interpreted in many ways, for example as conditional independence between random vectors, as points with certain distances in an inner product space, as pairs not to be compared in a rank test, or as separation in graphs or topological spaces. In this talk I will discuss the geometry of these structures and their analogies in other Coxeter types.
16:15 - 22:00	Meet the math
19:00 -	Dinner in the city (on the basis of individual payment)

Participants

Gianira Alfarano

University of Zurich

Carlos Améndola

TU Berlin / MPI-MiS

Amar Bapić

University of Primorska/Otto-von-Guericke-Universität Magdeburg

Tobias Boege

Max Planck Institute for Mathematics in the Sciences

Marie Brandenburg

MPI MiS

Xiangying Chen

OvGU Magdeburg

Isobel Davies

Otto-von-Guericke Universität Magdeburg

Philip Dörr

OVGU Magdeburg

Alex Elzenaar

MPI MiS

Samantha Fairchild

MPI MiS + Osnabrück

Ulf Friedrich

OVGU Magdeburg

Benjamin Hollering

MPI MiS

Naihuan Jing

North Carolina State University/MPI MiS

Thomas Kahle

Otto-von-Guericke Universität Magdeburg

Volker Kaibel

OVGU Magdeburg

Andreas Kretschmer

OvGU Magdeburg

Julia Lindberg

Max Planck Institute for Mathematics in the Sciences

Nima Rose Manjila

TU Chemnitz

Alessandro Neri

Max Planck Institute for Mathematics in the Sciences

Janike Oldekop

OvGU Magdeburg

Gabriel Ong

Bowdoin College

Ángel David Ríos Ortiz

MPI MiS

Pierpaola Santarsiero

Max Planck Institute for Mathematics in the Sciences

Daria Shaydurova

Otto-von-Guericke Universität Magdeburg

Linus Sommer

Universität Leipzig

Rishi Sonthalia

UCLA

Mima Stanojkovski

RWTH Aachen University / MPI MiS Leipzig

Bernd Sturmfels

Max Planck Institute for Mathematics in the Sciences

Julian Vill

OvGU Magdeburg

Claudia Yun

MPI MiS

Scientific Organizers

Tobias Boege

Max Planck Institute for Mathematics in the Sciences

Administrative Contact

Saskia Gutzschebauch

Max Planck Institute for Mathematics in the Sciences Contact via Mail