In this paper we study the following class of fractional Choquard--type equations \[ (-\Delta)^{ 1/2}u + u=\Big( I_\mu \ast F(u)\Big)f(u), \quad x\in\mathbb{ R}, \] where $(-\Delta)^{ 1/2}$ denotes the $1/2$--Laplacian operator, $I_{ \mu}$ is the Riesz potential with $0<\mu<1$ and $F$ is the primitive function of $f$. We use Variational Methods and minimax estimates to study the existence of solutions when $f$ has critical exponential growth in the sense of Trudinger--Moser inequality.
Categories: math.AP