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arXiv · 2508.18394

Exponential sums over primes are unbounded

Péa Bazin
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Abstract

We prove prime exponential sums have no better than square root cancellation on average on short intervals, in the sense that $$\frac{1}{x} \sum_{-y< n\le x} \left|\sum_{\substack{n< m \le n+y\\ 1\le m \le x}} \Lambda(m) \mathrm{e}(\alpha m)\right|^2 \gg y\log y$$ whenever $y \ll x^{1/3-\varepsilon}.$ This answers a question of Aymone and Ramar\'e by proving the lower bound $$\sup_{n\le x} \left|\sum_{m\le n} \Lambda(m) \mathrm{e}(\alpha m)\right| \gg x^{1/6 - \varepsilon}.$$

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Péa Bazin. 2025-08-25. Exponential sums over primes are unbounded. https://arxiv.org/abs/2508.18394

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