# Upper triangular matrix with empty space in lower triangular

How to represent this upper triangular matrix?

I'm not sure which part of the matrix was giving you trouble, but here's a sample:

\documentclass{amsart}

\DeclareMathOperator{\Var}{Var}
\DeclareMathOperator{\Cov}{Cov}

\begin{document}

$\Var(\epsilon) = \begin{bmatrix} \Var(\epsilon_1) & \cdots & \cdots & \cdots & \Cov(\epsilon_1,\epsilon_p) \\ & \Var(\epsilon_2) & \cdots & \cdots & \Cov(\epsilon_2,\epsilon_p) \\ & \ddots & \cdots & \cdots & \vdots \\ & & \ddots & \cdots & \vdots \\ & & & \ddots & \vdots \\ & & & & \Var(\epsilon_p) \end{bmatrix} = \Omega_{(np\times np)}.$

\end{document}


Notice that I've made Var and Cov into operators, which affects how they're typeset. The output: