There are times that we wanted to position an equation on the top right of the slide in beamer. The easiest way to do it is to use two packages: textpos and eso-pic. textpos package positions the textblock, while eso-pic sets up a grid system on the slides.

We include the two packages with options.

\usepackage[absolute,overlay]{textpos}
\usepackage[texcoord,
grid,gridcolor=red!10,subgridcolor=green!10,gridunit=pt]
{eso-pic}

To position a textblock, use the options \begin{textblock}{WIDTH}(XCOORDINATE,YCOORDINATE). Here is an example.

\begin{textblock*}{10pt}(150pt,1pt)
\small
\begin{equation*}
    \mathbf {H} = \frac{1}{2}\left( - \omega_{\mathrm{m}} + {\color{red}\delta \lambda(x)} \cos 2\theta_{\mathrm{m}} \right) \sigma_3 - \frac{  {\color{red}\delta \lambda(x)}  }{2} \sin \theta_{\mathrm{m}} \sigma_1
\end{equation*}
\end{textblock*}