Sage Days 116

• Dates: Dec 27-30, 2022

• Venue: Sol Beach, Yangyang, South Korea

• Organizing Committee
  • Meesue Yoo, Chair (Chungbuk National University)

  • JiSun Huh (Ajou University)

  • Jang Soo Kim (Sungkyunkwan University)
• Planary Speakers
  • Yasuhide Numata (Hokkaido University)
  • Travis Scrimshaw (Hokkaido University)
  • Heesung Shin (Inha University)
• Invited Speakers
  • Sangwook Kim (Chonnam National University)
  • Eunjeong Lee (Chungbuk National University)
  • Taehyeok Huh (Seoul National University)
  • Seung Jin Lee (Seoul National University)
• Software demo
  • Jang Soo Kim (Sungkyunkwan University)
• Schedule

Abstracts

Plnary Talks

** Yasuhide Numata (Hokkaido University) My talk 1: title: On data structures of Python/Sage. Abstract: First, I will introduce fundamental data structures of Python. Roughly speaking, Sage is Python with additional structures. The original data structures of Python can be used in Sage, too. Some of them are, however, overwritten. We see the difference between Python and Sage.

My talk 2: title: How to use classes as user of Sage. Abstract: First, we see basic syntax to define a new class in Python. Then I will introduce how to extend some class as a user of Sage.

Proposed project: Title: To make korean quick references. Level: For new bee. Abstract: We have quick references [1], i.e., cheat sheets. Almost of them are distributed with GFDL, and some of them are translated into some languages. We, however, have no Korean version. So translate them into Korean, or make a new reference for your research topics. I hope that the source code of Japanese translation might be helpful. [1] https://wiki.sagemath.org/quickref

** Travis Scrimshaw (Hokkaido University) - Talk 1 Title: The details of contributing to SageMath Abstract: In this talk, we will discuss how to prepare your code for inclusion into SageMath. These include things such as: (1) how to find the right place to put your code; (2) formatting your code, e.g., PEP8; (3) writing (good) documentation and doctests. Additionally, we will look at the current development model for SageMath and go through the contribution process. Lastly, we see what will change with the upcoming transition to GitHub's model.

- Talk 2 Title: Getting the full potential from SageMath Abstract: SageMath is built from numerous open source packages, but there are additional packages that are not installed by default (optional/experimental packages) and those further built on top of Sage (downstream packages). We will discuss some of these packages and how to install them from a source build, and highlight some of them and how they expand the computational abilities of SageMath (with the speaker's bias). Furthermore, not every feature of these packages (such as GAP) are immediately accessible in SageMath. We discuss how to access some of these packages within SageMath and leverage some of their more advanced capabilities (which make for good things to contribute to SageMath).

** Heesung Shin (Inha University) Sage Tutorial 1: Sage as a Calculator In the first tutorial, we will look at some simple SageMath commands that can be used like a calculator.

Sage Tutorial 2: Analysis and Algebra In the second tutorial, we will practice SageMath commands that are often used in analysis and algebra.

Sage Tutorial 3: Graphics and Programming In the third tutorial, you will run some commands used in SageMath for 2D or 3D visualization. If possible, we will cover programming that includes loops and conditional statements in SageMath.

See also: https://ensual.github.io

* Research Talks ** Sangwook Kim (Chonnam National University) Enumeration of Schröder paths by type using Sage

A Schröder path is a lattice path from (0, 0) to (n, n) using east, north and diagonal steps that lies weakly above the diagonal line y = x. The type of a Schröder path is the integer partitions which records the length of consecutive of east steps. Explicit formulas for the number of large and small Schröder paths of given type and number of connected components are provided. We also discuss how Sage is used to find formulas.

** Eunjeong Lee (Chungbuk National University) On toric varieties in the flag variety

Let G be a simple Lie group and let B be a Borel subgroup. The homogeneous space G/B becomes a smooth projective variety called the flag variety. The flag variety provides an interesting connection between geometry, topology, representation theory, and combinatorics as is exhibited in the Borel-Weil-Bott theorem, Schubert calculus, and so on. A maximal (complex) torus T acts on the flag variety and there are lots of toric varieties with respect to this torus action. Indeed, the T-orbit closure of a point in the flag variety is always a toric variety. One can produce toric Schubert varieties and toric Richardson varieties in this way. In this talk, we study toric varieties in the flag variety, especially certain smooth toric Richardson varieties containing toric varieties of Catalan type and toric Schubert varieties. This talk is based on joint work with Mikiya Masuda and Seonjeong Park.

** Taehyeok Huh (Seoul National University)

The crystal structure of King tableaux

The King tableau is a symplectic generalization of semistandard tableaux, which describes irreducible modules over symplectic Lie algebras. Whereas it is a very well-known object in combinatorics, its crystal structure is not, but Lee recently explains its crystal structure via oscillating tableaux. In this talk, I will briefly explain the crystal structure of King tableaux. This talk is a review of Lee's article (arXiv:1910.04459).

** Seung Jin Lee (Seoul National University) TBA

* Software demo ** Jang Soo Kim (Sungkyunkwan University)