12th polymake conference and developer meeting

On Friday there will be two invited talks and several tutorials, demos and helpdesk sessions for polymake users.

The conference takes place digitally using Zoom: the links will be placed in the dedicated section of this page.

Participants are encouraged to use a laptop with an installed version of polymake in the tutorials. If you have any polymake problem you want to get help during the workshop please describe your problem during the sign up process.

Please fill out the registration form!

One may construct an edge cone/polytope by the columns of the incidence matrix of a graph. First we consider affine toric varieties associated to the edge cone of a bipartite graph. The first-order deformations of an affine toric variety is combinatorially described by Altmann. By applying this result, we study the ones with no nontrivial first-order deformations, i.e. rigid ones. Next we focus on Gorenstein toric Fano varieties arising from symmetric edge polytopes. We investigate the rigid ones by Totaro‘s result in terms of graphs.

The latter is a joint-work with Selvi Kara and Akiyoshi Tsuchiya.

The Ehrhart polynomial counts the number of lattice points in integer dilates of a lattice polytope. The h*-polynomial of a lattice polytope is the numerator of the generating function of the Ehrhart polynomial. In this talk, we discuss the h*-polynomials of locally anti-blocking lattice polytopes. In particular, I give a formula of h*-polynomial of a locally anti-blocking lattice polytope. Moreover, I introduce several classes of locally anti-blocking lattice polytopes arising from graphs and posets and give formulas of their h*-polynomials in terms of the underlying graphs and posets. Finally, I give a conjecture on the h*-polynomial of a locally anti-blocking lattice polytope.

This talk is based on joint work with Hidefumi Ohsugi (Kwansei Gakuin University).

If you are new to polymake and wish to understand a bit more about it, this is the right place for you. From 14:00 to 15:00 we will have three sessions of half an hour each in which expertes of the field will introduce you to the three main polymake applications: polytope, fulton and tropical. Notice that the two sessions about polytopes and tropical will be held in parallel. Be sure to make your choice wisely.

If you first came across polymake using Oscar (check it out Oscar) and you want to know more about how to use polymake in Julia, then you should join this useful half an hour tutorial. This session will be held in parallel with the fulton application tutorial.

Real embedded number fields offer practicable precise possibilities to deal with special values which can not be represented as a rational number. E-ANTIC is a library offering functionalities, especially arithmetic and comparison, in this context and is the foundation of an upcoming polymake extension. This tutorial explains the basic usage of the extension, introducing the new scalar type NumberFieldElement and giving some example applications.

The event will take place in three main zoom rooms, the orange, the black and the white. The orange room is the main hall.

• Orange room: https://tu-berlin.zoom.us/j/66548757163
• Black room: https://tu-berlin.zoom.us/j/67436957044
• White room: https://tu-berlin.zoom.us/j/69664897255

To access the rooms, you need a password that will be sent via email to the registered participants.

• Welcome and goodbye: Orange
• First talk by Irem Portakal: Orange
• Tutorial for application Polytope: Orange
• Tutorial for application Tropical: Black
• Tutorial for Number fields: White
• Tutorial for application Fulton: Orange
• Tutorial Polymake via Julia: Black
• Second talk by Akiyoshi Tsuchiya: Orange

For the helpdesks we will use matrix. If you already have a matrix account e.g. on https://matrix.org or via your TU Berlin account at https://chat.tu-berlin.de then you can join here or by directly joining the room #workshop:polymake.org in your matrix client. Otherwise you can create a new matrix account on the polymake server here. Please click the link and follow these steps:

1. Click 'Create account'
2. Choose a username and password.
3. Click 'Register'
4. Click 'Join the discussion'.

The main room is for general questions and will also be used for the dedicated installation helpdesk on Friday. However if you have time, please try to install polymake beforehand and feel free to contact us on riot before the workshop.

The quiz sheet is the following: quiz.pdf. The file to decrypt the message is:message.txt.gpg . To get the passphrase for the encrypted message just chain together all the answers from the questions in their order. Leave out commas and use 0 and 1 for true and false. The answer should be a string of 20 digits.

The developer meeting takes place on January 28th and 30th. The schedule for the developer meeting and the informations for accessing it will be sent by email to the registered participants. You can find more information on the developer meeting here (internal access only). If you want to participate in the developer meeting as well, please let us know by email.

1. Mara Belotti
2. Lars Kastner

Please contact us with any questions about the workshop. To email us, please use LASTNAME@math.tu-berlin.de.