Convexity and log-concavity of the partition function weighted by the parity of the crank
Let [Formula: see text] (resp. [Formula: see text]) denote the number of partitions of n with even (resp. odd) crank. Choi, Kang and Lovejoy established an asymptotic formula for [Formula: see text]. By utilizing this formula with the explicit bound, we show that [Formula: see text] for [Formula: see text] or 1 and [Formula: see text]. This result can be seen as the refinement of the classical result regarding the convexity of the partition function [Formula: see text], which counts the number of partitions of n. We also show that [Formula: see text] (resp. [Formula: see text]) is log-concave for [Formula: see text] and satisfies the higher order Turán inequalities for [Formula: see text] with the aid of the upper bound and the lower bound for [Formula: see text] and [Formula: see text].
Authors
- Janet J. W. Dong
- Kathy Q. Ji (ORCID: https://orcid.org/0000-0001-7658-9462)
Institutions
- Tianjin University (CN)
- Shaoxing University (CN)
Publication Details
- Journal
- International Journal of Number Theory
- Published
- 2025-01-22
- DOI
- https://doi.org/10.1142/s1793042125500629
- Primary Topic
- Analytic Number Theory Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00