On Improving Roth's Theorem in the Primes

Abstract: Let $A\subset\left{ 1,\dots,N\right} $ be a set of prime numbers containing no non-trivial arithmetic progressions. Suppose that $A$ has relative density $\alpha=|A|/\pi(N)$, where $\pi(N)$ denotes the number of primes in the set $\left{ 1,\dots,N\right} $. By modifying Helfgott and De Roton's work, we improve their bound and show that $$\alpha\ll\frac{\left(\log\log\log N\right)^{6}}{\log\log N}.$$