%0 Journal Article %T One-dimensional random walks with self-blocking immigration %A Matthias Birkner %A Rongfeng Sun %J Mathematics %D 2014 %I arXiv %X We consider a system of independent one-dimensional random walkers where new particles are added at the origin at fixed rate whenever there is no older particle present at the origin. A Poisson ansatz leads to a semi-linear lattice heat equation and predicts that starting from the empty configuration the total number of particles grows as $c \sqrt{t} \log t$. We confirm this prediction and also describe the asymptotic macroscopic profile of the particle configuration. %U http://arxiv.org/abs/1410.4344v2