Dear all,
The upcoming CART seminar is scheduled for April 18th (Friday), 16:00 - 17:00 (Korea time).
Please notice the unusual time.
Speaker: Sean Griffin (University of Vienna, Austria) Title: On Macdonald expansions of q-chromatic symmetric functions and the Stanley-Stembridge Conjecture Abstract: The Stanley-Stembridge conjecture asserts that the chromatic symmetric function of a (3+1)-free graph is e-positive, meaning that it expands positively in the elementary symmetric function basis. Motivated by a geometric construction of Kato, recently Hikita proved this conjecture by giving an explicit e-expansion of the Shareshian-Wachs q-chromatic refinement (or chromatic quasisymmetric function) for unit interval graphs. Using the A_{q,t} algebra of Carlsson and Mellit, we give an expansion of these q-chromatic symmetric functions into Macdonald polynomials. Upon setting t=1, we obtain another proof of the Stanley-Stembridge conjecture and rederive Hikita's formula. Upon setting t=0, we obtain an expansion into Hall-Littlewood symmetric functions. This is joint work with Mellit, Romero, Weigl, and Wen.
You can join the seminar via the following
Zoom link: https://us06web.zoom.us/j/81269364430?pwd=9vb0YlUq2fX31EFOV24YRGMoWlbQSa.1 Meeting ID: 812 6936 4430 Password: 159706
Please feel free to forward this to anyone who might be interested. You can check out further information on CART seminar on our website (https://sites.google.com/view/cart-kias/).
Looking forward to seeing you at the seminar!
Best regards, Jaeseong Oh