workshops:workshop0121

12th polymake conference and developer meeting

January 29th, 2021

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.

Registration:

Please fill out the registration form!

Schedule:

Friday Talks Helpdesks
10:30-11:45 Installation helpdesk
11:45-12:00 Welcoming and summary of Polymake
12:00-13:00 Talk: Rigidity of toric varieties arising from graphs
Irem Portakal
13:00-14:00 Lunch Various helpdesks, see table
14:00-14:30 Tutorial: Application Polytope Tutorial: Application Tropical
Oğuzhan Yuruk Sylvain Spitz
14:30-15:00 Tutorial: Application Fulton Tutorial: using Polymake via Julia
Holger Eble Taylor Brysiewicz
15:00-16:00 Talk: Ehrhart theory of locally anti-blocking lattice polytopes
Akiyoshi Tsuchiya
16:00-16:30 Conclusion
16:30- Various helpdesks, see table

Abstracts

Talk: Ehrhart theory of locally anti-blocking lattice polytopes

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).

Talk: Rigidity of toric varieties arising from graphs

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 classify the rigid ones by Totaro‘s result in terms of graphs.

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

Tutorials regarding polymake applications

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.

Tutorial: using Polymake via Julia

If you first came across polymake using Oscar (check it out https://oscar.computeralgebra.de/) 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.

In time for the workshop, this section will contain all the necessary links to access the online event.

  • First talk by Irem Portakal:
  • Tutorial Basic for Polytope:
  • Tutorial Basic for Tropical:
  • Tutorial Basic for Fulton:
  • Tutorial Polymake via Julia:
  • Second talk by Akiyoshi Tsuchiya:

If you have any question regarding polymake, there will be people ready to answer you. To allow such Q&A, we will be using the Riot (https://riot.im/app) instant chat app. You need to create an account there and then access the room #workshop:polymake.org. Once in there, fell free to type any question you might have, from installation problem to doubts related to a specific polymake application.

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.

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

  • workshops/workshop0121.txt
  • Last modified: 2021/01/22 21:53
  • by lkastner