PreprintCC BY-NC-SA 4.0arXiv
A Sharp Bound for Additive Complements
Abstract
Let A and B be infinite sets of nonnegative integers whose sum contains all sufficiently large integers, and let A(x) and B(x) be their counting functions. We give a discrete proof of the sharp implication limsupx→∞A(x)B(x)/x<3/2 Longrightarrow A(x)B(x)−x⟶+∞. The constant 3/2 is best possible. Using finite convolution sums, we show that a long gap in one set forces a gap in the other. We then compare the counting functions before and after the gap to obtain the sharp bound.
Related
BibTeX
@misc{zhang2026sharp,
title = {{A Sharp Bound for Additive Complements}},
author = {Zihan Zhang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.29963},
eprint = {2610.29963},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.29963},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - A Sharp Bound for Additive Complements
AU - Zihan Zhang
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2610.29963
UR - https://arxiv.org/abs/2610.29963
AB - Let A and B be infinite sets of nonnegative integers whose sum contains all sufficiently large integers, and let A(x) and B(x) be their counting functions. We give a discrete proof of the sharp implication limsup_x→∞A(x)B(x)/x<3/2 Longrightarrow A(x)B(x)−x⟶+∞. The constant 3/2 is best possible. Using finite convolution sums, we show that a long gap in one set forces a gap in the other. We then compare the counting functions before and after the gap to obtain the sharp bound.
ER -