The first-increase inequalities for connected unit interval graphs

Let GG) be a connected unit interval graph defined by the weakly increasing sequence m=(m1,m2,,mn1){\bf m}=(m_1,m_2,\ldots,m_{n-1}), where imini\leq m_i\leq n for all i[n1]i\in[n-1]. Let mr<mr+1m_r<m_{r+1} be the first increase, and let GG' be the unit interval graph defined by

m=(m1+1,,mr+1,mr+1,,mn1).{\bf m}'=(m_1+1,\ldots,m_r+1,m_{r+1},\ldots,m_{n-1}).

First-increase inequalities. One has

GeGandGsG.G\geq_e G'\qquad\text{and}\qquad G\geq_s G'.

These inequalities are proposed as part of a sequence of comparisons between connected unit interval graphs that could establish their ee-positivity and Schur-positivity. The Schur-positivity consequence is already known for unit interval graphs, while the corresponding ee-positivity goal remains open in the stated context.

Sources & referencesView supporting material

Primary source

Samantha Dahlberg, Adrian She and Stephanie van Willigenburg, “Chromatic Posets”, arXiv:1909.12394 (2020).

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.