Bound for heat equation solution in 1D – math.stackexchange.com

Guillermo García Sáez
Let $u$ solve the heat equation$$ u_t = u_{xx} \quad \text{in } (0,\pi)\times(0,\infty),$$ with Dirichlet boundary conditions $$ u(0,t)=u(\pi,t)=0,$$ and initial data $$ u(x,0)=f(x), $$ where $f \in ...