Simple random walk in two dimensions is recurrent
= Simple random walk in two dimensions is recurrent
A <simple random walk> on $\mathbb Z^2$ visits its starting point infinitely often <almost surely> and hits every fixed vertex <almost surely>.
= Simple random walk in two dimensions is recurrent
A <simple random walk> on $\mathbb Z^2$ visits its starting point infinitely often <almost surely> and hits every fixed vertex <almost surely>.