>>218 関連
ヤンバクスター方程式ねー、昔からよく見る名前だが・・
これか、統計力学の理論ね。イジングモデル（>>200など）の系譜やね

https://en.wikipedia.org/wiki/Yang%E2%80%93Baxter_equation
Yang?Baxter equation
In physics, the Yang?Baxter equation (or star-triangle relation) is a consistency equation which was first introduced in the field of statistical mechanics. It depends on the idea that in some scattering situations, particles may preserve their momentum while changing their quantum internal states.

In one dimensional quantum systems, {\displaystyle R} R is the scattering matrix and if it satisfies the Yang?Baxter equation then the system is integrable.
The Yang?Baxter equation also shows up when discussing knot theory and the braid groups where {\displaystyle R} R corresponds to swapping two strands. Since one can swap three strands two different ways, the Yang?Baxter equation enforces that both paths are the same.

It takes its name from independent work of C. N. Yang from 1968, and R. J. Baxter from 1971.

https://www.encyclopediaofmath.org/index.php/Yang-Baxter_equation
Yang?Baxter equation. Encyclopedia of Mathematics. This page was last modified on 24 March 2012, at 20:54.