Abstract:
A finite set
$A=\{a_1<\dotsb<a_n\}\subset\mathbb R$
is said to be convex if the sequence
$(a_i-a_{i-1})_{i=2}^n$
is strictly increasing.
Using an estimate of the additive energy of convex sets,
one can estimate the size of the sumset as
$|A+A|\gtrsim|A|^{102/65}$,
which slightly sharpens Shkredov's latest result
$|A+A|\gtrsim|A|^{58/37}$.