Bertrand's Postulate gives us that:
$$p_n < p_{n+1} < 2p_n$$
So that:
$$p_{n+1} - p_n < p_n$$
In this answer, this paper is cited which says in Prop 6.8 that:
For $x \ge 396738$ there is always a prime in the interval $[x, x + x/(25\ln^2 x)]$
Is this the best upper bound known for consecutive primes?
If I understand it correctly, does it mean that:
$$p_{n+1} - p_n < \frac{p_n}{25\ln^2 p_n}$$