Boundary regularity for fractional porous medium-type equations in bounded domains

We prove boundary Hölder regularity for fractional porous medium-type equations in bounded smooth domains with zero exterior data. For $02σ$, and $m>1$, we show that nonnegative weak dual solutions $v$ of $\partial_t v+(-Δ)^σ(v^m)=0$ satisfy \[ \frac{v}{d^{σ/m}}\in C_{x,t}^{α,\frac{αm}{σ(m