====== 2023-05-30 ======

visit to U Oregon.

===== talking with Ben Elias =====

==== Singular Soergel Bimodule ====
It is very useful to consider singular Soergel module. 

Question: is crossing the same as merge then split? 

What is $x_1, x_2$? Consider $Fl(0,1,2)$, the complete flag in $\C^2$ 

==== taking trace ====
In a 2-category, there are more directions to make a line segment into a circle. There are the monoidal direction, the 1-categorical direction. And, there are the omp

==== a non-trivial test of geometry ====
Consider 4 strands, full twists. (Closed) Bott-Samuelson variety, stusts to utustu, where s t u are the $s_1, \cdots, s_3$. The two movies gives equivalent morphisms of Bott-Samelson module, which is equivalent to total merge, and total split. Not true if you start from other positions. Can you use geometry to explain why? 

==== Goresky-Negut-Rasmussen ====
Consider the finite Hecke algebra. We have the commutative algebra YJM, and the center Z.
$$ Z \into YJM \into H_{fin} $$

There are categorification of finite Hecke algebra, into finite Hecke category. 
$$ Z \into YJM \into H_{fin} $$