If I use the following set of Fourier transforms:
$$\mathcal F(w) = \int_{0}^T dtf(t)e^{iwt},$$
$$ f(t) = \frac{1}{2\pi} \int_{-w_N}^{w_N} dw\mathcal F(w)e^{-iwt},$$
where $f(t)$ is an arbitrary time domain signal with total duration $T$, $w= 2\pi f$ is angular frequency, and $w_N$ is the Nyquist angular frequency. The underlying assumption here is that the signal $f(t)$ is casual in the sense that it has a zero value for $t \leq 0$.
Now, what is the inverse Fourier Transform of $\sqrt {-iw} \mathcal F(w)$:
${}$ $$\mathcal F^{-1} (\sqrt {-iw} \mathcal F(w))=\quad?$$
${}$
Any help is appreciated.
Hint. Refer Table of Fourier/Inverse Fourier transform. And make it a good habit to write the differential after the integrand.