The Haglund–Morse–Zabrocki parking-function bijection conjecture

About 14 years old · traced to

Let PFPF be a parking function, let area⁡(PF)\operatorname{area}(PF), dinv⁡(PF)\operatorname{dinv}(PF), and ides⁡(PF)\operatorname{ides}(PF) denote its area, diagonal inversion number, and inverse descent set, and let Ac\mathcal{A}_c be the set of parking functions with composition cc. Write

c=[c1,…,ck]=[c′,ci,ci+1,c”],c=[c_1,\ldots,c_k]=[c',c_i,c_{i+1},c”],

where c′c' and c”c” are the parts before and after ci,ci+1c_i,c_{i+1}. The Haglund–Morse–Zabrocki bijection conjecture. If ci≤ci+1−1c_i\leq c_{i+1}-1, there exists a bijection

f:A[c′,ci,ci+1,c”]∪A[c′,ci+1−1,ci+1,c”]⟷A[c′,ci+1,ci,c”]∪A[c′,ci+1,ci+1−1,c”]f:\mathcal{A}_{[c',c_i,c_{i+1},c”]}\cup\mathcal{A}_{[c',c_{i+1}-1,c_i+1,c”]}\longleftrightarrow\mathcal{A}_{[c',c_{i+1},c_i,c”]}\cup\mathcal{A}_{[c',c_i+1,c_{i+1}-1,c”]}

that increases dinv⁡\operatorname{dinv} by exactly one and preserves ides⁡\operatorname{ides} and area⁡\operatorname{area}. This bijection would realize the commutativity relations predicted by the Haglund–Morse–Zabrocki conjectures at the level of parking functions; the source gives no resolution, so the claim remains open.

References

Primary source

Angela Hicks, “A Parking Function Bijection supporting the Haglund-Morse-Zabrocki Conjectures”, arXiv:1210.2705 (2012).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.