Causal extension by zero
= Causal extension by zero
{title2=$f_0(t)=f(t)\ (t\geq0),\quad f_0(t)=0\ (t<0)$}
Extend a <function> given for nonnegative time to the <real line> by setting it to zero before the starting time. This turns unilateral <convolution> into whole-line <convolution> and identifies a <Laplace transform> slice with a <Fourier transform> after <exponential function> weighting.