\documentclass[12pt,letterpaper]{article} \usepackage[T1]{fontenc} \usepackage{amsmath} \begin{document} \begin{align} ds^2 &= dt^2 - \ell_{\Lambda}^2 \sinh^2 {\omega t} \, \big( \, d\chi^2 + \sinh^2 {\chi} \; (\, d\vartheta^2 + \sin^2 {\vartheta} \; d\varphi^2 ) \big), \\[18pt] ds^2 &= dt^2 - \ell_{\Lambda}^2 \cosh^2 {\omega t} \, \big( \, d\chi^2 + \sin^2 {\chi} \; (\, d\vartheta^2 + \sin^2 {\vartheta} \; d\varphi^2 ) \big). \end{align} \end{document}

I need the angular parts ($d\vartheta^2 + \sin^2 \vartheta \; d\varphi^2$ **) to be perfectly aligned, for aesthetical reasons only. Of course, the alignment problem is caused by the hyperbolic functions which don't have exactly the same number of letters (and same letters shape) as the trigonometric functions.

Here's a preview of what the code above is doing, and the problem indicated in red :

So how should I achieve the alignment I'm looking for ?

** Why on Earth can't I use simple LaTeX commands on a LaTeX board here !? The LaTeX symbols should be displayed correctly, instead of showing the commands !

EDIT : Inserting the command

`\phantom{h}`

inside the second equation doesn't do the trick very well, since it gives an exagerated visible space after the `sin^2 {\chi}`

function. I tried adding `\,`

and `\;`

here and there, but the result isn't satisfying (too approximate).I guess the solution is to center the

`\sin^2 {\chi}`

by adding more space at its left and at its right, to balance the `\sinh^2 {\chi}`

above it.