4

How do I add the $\theta_t \in \Theta$ in $$\theta_t^* = {\arg \min}_{\theta_t \in \Theta} \mathbb{E}$$ so that it goes directly underneath the $\arg \min$?

EDIT: I should have specified this earlier, but I'm primarily interested in something that would work on stackexchange sites, such as math.stackexchange.

The Pointer
  • 309
  • ---ah, but that is MathJax, not TeX --- they are different things that happen to use the same language. More or less ;-) --- see the tag description: https://tex.stackexchange.com/questions/tagged/mathjax – Rmano Sep 29 '20 at 10:05

2 Answers2

7

\limits can be applied to a math operator, to indicate that sub/super-scripts should go below/above the operator.

\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}
\[
\theta_t^* = \mathop{\arg \min}\limits_{\theta_t \in \Theta} \mathbb{E}
\]
\end{document}

enter image description here

Steven B. Segletes
  • 237,551
  • I was playing around with \limits, since I've used it before with \sum, but I just couldn't get it to work. Thanks! – The Pointer Sep 28 '20 at 17:43
4

You could declare a new math operator with the command \DeclareMathOperator* from amsmath. When the starred version of this command is used, superscripts and subscripts of the new operator are placed as they would be placed with \limits.

\documentclass{article}
\usepackage{amsmath, amssymb}
\DeclareMathOperator*{\argmin}{arg\,min}
\begin{document}
\[
\theta_t^* = \argmin_{\theta_t \in \Theta} \mathbb{E}
\]
\end{document}

Also, note that you should use \[ ... \] instead of $$ ... $$.

Vincent
  • 20,157
  • I should have specified, but I was primarily interested in something that would work on stackexchange sites, such as math.stackexchange. – The Pointer Sep 28 '20 at 17:45