We give a relatively simple proof that \[ \int _0^1\left |\sum _{n\leq x}d(n)e(n\alpha )\right |d\alpha \asymp \sqrt x.\]
On the $L^1$ norm of an exponential sum involving the divisor function
Moments of an exponential sum related to the divisor function
On the mean value of the magnitude of an exponential sum involving the divisor function
![QR code for arXiv:2404.04747 [math.NT]](http://oss.arxitics.com/images/favicon.svg)