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arXiv 2408.01385math.CO
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KPKP图、孪生棒棒糖图及皮划桨图的正$e_I$-展开式

Positive $e_I$-expansions for KPKP graphs, twinned lollipops, and kayak paddles

Beijing Institute of Technology(北京理工大学)

Davion Q. B. Tang, David G. L. Wang

AI总结:

该研究推导了KPKP图、孪生棒棒糖图及皮划桨图等图族的色对称函数的正$e_I$-展开式,完善了普通$e$-正性并补充了相关证明方法。

摘要:

我们推导了若干图族的色对称函数的显式正$e_I$-展开式。首先,得到KPKP图的统一公式,该公式可特化为棒棒糖图、KPK图、KKP图及PKP图的已知公式;接着,给出孪生路径与孪生环的正$e_I$-展开式,并将KPKP公式应用于孪生棒棒糖图;最后,建立皮划桨图的正$e_I$-展开式并将其特化为无穷图。这些公式通过保留组合索引系数,完善了普通$e$-正性,且提供了与现有递推、单位区间及非交换方法互补的独立证明。

英文摘要:

We derive explicit positive $e_I$-expansions for the chromatic symmetric functions of several graph families. First, we obtain a uniform formula for KPKP graphs that specializes to known formulas for lollipops, KPK graphs, KKP graphs, and PKP graphs. We then give positive $e_I$-expansions for twinned paths and cycles and apply the KPKP formula to twinned lollipops. Finally, we establish a positive $e_I$-expansion for kayak paddles and specialize it to infinity graphs. These formulas refine ordinary $e$-positivity by retaining composition-indexed coefficients and provide independent proofs complementary to existing recurrence, unit-interval, and noncommutative methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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