The Art of Bijective Combinatorics Part III
The cellular ansatz: bijective combinatorics and quadratic algebra
The Institute of Mathematical Sciences, Chennai, India (January-March 2018)
January 4, 2018
Chapter 0 Overview of the course
slides of Ch0 (pdf 17 Mo, version2)
video Ch0: link to Ekalavya (IMSc Media Centerr)
video Ch0: link to YouTube
video Ch0: link to bilibili
recalling Part I of the bijective combinatorics course: enumerative combinatorics: 01:27
Catalan numbers and n! p6 01:40
number of Young tableaux 10 02:13
A beautiful identity 15 04:07
algebraic combinatorics: an example 21 05:40
bijective combinatorics: RSK 24 07:36
the idea of "bijective tools" 30 10:22
Part III of the bijective course: the cellular ansatz 38 12:20
First step of the cellular ansatz: quadratic algebra Q and associated Q-tableau 41 13:18
with the example Q defined by the relation UD = DU + Id 13:41
normal ordering 14:34
permuations and normal ordering 16:43
why the name "cellular ansatz": planarization of the rewriting rules 17:29
planarization of the rewriting rules 17:43
permutations as complete Q-tableaux 45 20:53
permutations as Q-tableaux 21:59
Rothe diagrams as Q-tableaux 22:19
Planar automata and Q-tableaux 80 23:20
finite automaton 23:42
alternating sign matrices recognized by a planar automaton 24:57
the idea of planar automata 25:54
the quadratic algebra associated to alternating sign matrices 27:33
First step of the cellular ansatz (sumary) 27:58
Second step of the cellular ansatz 28:23
The Robinson-Schensted-Knuth (RSK) correspondence 89 28:51
Fomin's local rules (growth diagrams) 29:50
combinatorial representation of the algebra UD = DU +Id 31:02
Second step of the cellular ansatz (sumary) 91 32:25
Combinatorial physics 33:16
Combinatorial physics: example with the PASEP 95 33:38
The PASEP algebra 37:15
"normal ordering" for the PASEP algebra 37:53
alternative tableaux: definition 100 38:20
planarization of the rewriting rules of the PASEP algebra 40:30
alternative tableaux as Q-tableau of the PASEP algebra 105 42:19
Catalan alternative tableaux and the TASEP (q=0) 133 43:27
Enumeration of alternating tableaux 44:19
Representation of the PASEP algebra and the bijection EXF ("exchange-fusion") 138 44:35
RSK, EXF, tilings, paths, ASM, 8-vertex model, ... and much more, under the same roof 140 47:20
The njumber of alternating matrices 49:11
A summary of the course in a single tableau 49:58
demultiplication of the equations in a quadratic algebra 51:11
the end 150 0:53:58
The playlist from matsciencechannel of the 22 videos of this course is here