Expectations of normal variables

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The discussion centers on the expectations of products of independent normal variables, specifically the expressions mathbb{E}(1_{X_{1}+X_{2}>\rho}X_{1}X_{2}) and mathbb{E}(1_{X_{1}+X_{2}>\rho}X_{1}^{2}). Participants debate the definition of 'closed-form expression', highlighting that under a narrow interpretation, even basic probabilities involving normal distributions lack closed forms due to the absence of analytic formulas for their integrals. However, a broader interpretation suggests that the provided expressions could already be classified as closed-form.

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lequan
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\begin{eqnarray*}
&&\mathbb{E}\left( 1_{\left\{ X_{1}+X_{2}>\rho \right\} }X_{1}X_{2}\right)
\\
&&\mathbb{E}\left( 1_{\left\{ X_{1}+X_{2}>\rho \right\} }X_{1}^{2}\right)
\end{eqnarray*}

where ##X_1## and ##X_2## are independent normal variables. I am wondering whether there exist closed-form expressions for the above two expectations.
 
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What would you consider to be a 'closed-form expression'?
With a fairly common, narrow interpretation of 'closed form', even a simple univariate normal calculation such as ##Pr(X_1<x)## does not have a closed form because there is no analytic formula for the indefinite integral of the normal pdf.
Conversely, taking a broader interpretation, the two expressions you have written above could be considered to already be 'closed-form'.
 

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