Weakening the Legendre Conjecture

The world of primes has many gaps between evidence and theorems. Here, we review Legendre’s conjecture on primes between consecutive squares and recent progress on the weaker question of primes between consecutive larger powers. Assuming the Riemann hypothesis (RH), we observe that a recent result of Emanuel Carneiro, Micah Milinovich and Kannan Soundararajan, combined with a large-scale computation by Jonathan Sorenson and Jonathan Webster, implies the existence of primes between $x^{2+\delta }$ and $(x+1{)}^{2+\delta }$ for all real $x\ge 1$ when $\delta \ge 1\mathrm{/}4$. For smaller values of $\delta >0$, we provide an explicit bound $x_0=x_0(\delta )$ such that primes exist in these intervals whenever $x\ge x_0$ (again assuming RH). We conclude with an application to Mills-type prime-generating constants.