# Big equation does not fit in beamer

I have copied a math expression from Mathematica in a beamer frame.

The equation is so long that although I have splitted it into several lines, which are separated by a plus symbol, still does not fit in the frame.

I have tried all that I have found here, I have put the equation in a minipage, and then resized it to the text width, even I have enlargered the frame with \geometry but neither of this works for me.

The \geometry will change all my others frames and I don't want that.

Besides I want that the equation be aligned to the left side of the frame and I don't know how.

This is my code:

\documentclass{beamer}
\begin{document}
\begin{frame}

the scattering amplitude

\resizebox{\textwidth}{!}{
\begin{minipage}[]{\textwidth}
\large{
\begin{eqnarray}
\frac{2 \left(\text{tr} \left(\text{e}^4 \left(m_e-\bar{\gamma }\cdot \bar{K}\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_1}+\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}
{\left(\bar{K}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_2}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}
+\frac{2 \left(\text{tr} \left(\text{e}^4 \left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \left(\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \bar{K}+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}
{\left(\bar{K}^2-m_e^2\right).\left(\left(\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}
+\frac{2 \left(\text{tr} \left(\text{e}^4 \left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \bar{K}+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}
{\left(\bar{K}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}
\end{eqnarray}
}
\end{minipage}
}

\end{frame}
\end{document}


In here, as you can see, I have made not any splitting or enlarging of the page.

So maybe you can start to teach me how to split the expression properly.

• Off-topic: Are you sure this equation is useful on a beamer slide? You're audience probably won't remember all the terms in detail... – samcarter_is_at_topanswers.xyz Mar 8 '17 at 16:52
• @samcarter Hi, thanks for the advice but I am doing a presentation about a Mathematica package that can write and solve this, so I can show that is better check with Mathematica than doing it by hand cause is very easy get it wrong. I know that nobody will remember it but that is not the point. – NATALIA TAPIA Mar 8 '17 at 16:56
• @NATALIATAPIA - If "nobody will remember" this monstrous formula, you should have the guts -- and the decency -- not to show it. – Mico Mar 8 '17 at 17:53

If you're going to show this monster of a math expression at all, you should give your audience a fighting chance to take in at least some of the details. There are 3 additive components to the full equation, each consisting of fractions with dreadfully long numerators and denominators. I suggest you break up each of the numerators across 3 lines, and each of the denominators across 2 lines.

Note that I've removed all 78 \left directives, all 78 \right directives, all 24 \cdot directives, and lots of other . (dot) terms. They simply do not belong in a well-typeset math expression. I could have also eliminated further groups of parentheses that appear to be there purely for the convenience of Mathematica, but I chose to give it a rest. I did add, though, large parentheses to enclose the multi-line numerator and denominator terms.

\documentclass{beamer}
\usepackage{amsmath}
\DeclareMathOperator{\tr}{tr} % trace operator?
\begin{document}
\begin{frame}
\footnotesize  % <--- yes, this is needed
\begin{align*}
&\frac{\left(\begin{aligned}
2 \tr \bigl[&\text{e}^4 (m_e-\bar{\gamma} \bar{K})(\bar{\gamma} \bar{\varepsilon}(\text{k}_2))(\bar{\gamma} (-\overline{\text{k}_2}-\bar{K})+m_e)(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_2))\\
&\times(\bar{\gamma} (-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_2})+m_e)(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_1))\\
&\times(\bar{\gamma} (-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_1}+\overline{\text{q}_2})+m_e)(\bar{\gamma} \bar{\varepsilon}(\text{k}_1))\bigr]
\end{aligned}\right)}%
{\left(\begin{aligned}
&(\bar{K}^2-m_e^2)((\overline{\text{k}_2}+\bar{K})^2-m_e^2)\\
&\times((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_2})^2-m_e^2)((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2})^2-m_e^2)
\end{aligned}\right)}\\[1ex]
{}+{}
&\frac{\left(\begin{aligned}
2 \tr \bigl[&\text{e}^4 (\bar{\gamma} (\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2})+m_e)(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_2))\\
&\times(\bar{\gamma} (\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1})+m_e)(\bar{\gamma} \bar{\varepsilon}(\text{k}_2))(\bar{\gamma} (\bar{K}-\overline{\text{q}_1})+m_e)\\
&\times(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_1))(\bar{\gamma} \bar{K}+m_e)(\bar{\gamma} \bar{\varepsilon}(\text{k}_1))\bigr]
\end{aligned}\right)}%
{\left(\begin{aligned}
&(\bar{K}^2-m_e^2)((\bar{K}-\overline{\text{q}_1})^2-m_e^2)\\
&\times((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1})^2-m_e^2)((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2})^2-m_e^2)
\end{aligned}\right)}\\[1ex]
{}+{}&
\frac{\left(\begin{aligned}
2 \tr \bigl[&\text{e}^4 (\bar{\gamma} (\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2})+m_e)(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_2))\\
&\times(\bar{\gamma} (\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1})+m_e)(\bar{\gamma} \bar{\varepsilon}^*(\text{q}_1))\\
&\times(\bar{\gamma} (\overline{\text{k}_2}+\bar{K})+m_e)(\bar{\gamma} \bar{\varepsilon}(\text{k}_2))(\bar{\gamma} \bar{K}+m_e)(\bar{\gamma} \bar{\varepsilon}(\text{k}_1))\bigr]
\end{aligned}\right)}%
{\left(\begin{aligned}
&(\bar{K}^2-m_e^2)((\overline{\text{k}_2}+\bar{K})^2-m_e^2)\\
&\times((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1})^2-m_e^2)((\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2})^2-m_e^2)
\end{aligned}\right)}
\end{align*}
\end{frame}
\end{document}

• Thank you for your kindness @Mico, probably this will be better for the audience. – NATALIA TAPIA Mar 8 '17 at 18:52

Not sure how useful this is:

\documentclass{beamer}

\begin{document}
\begin{frame}[shrink=60]

\begin{align*}
&\frac{2 \left(\text{tr} \left(\text{e}^4 \left(m_e-\bar{\gamma }\cdot \bar{K}\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \left(-\overline{\text{k}_2}-\bar{K}+\overline{\text{q}_1}+\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}{\left(\bar{K}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_2}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}+\\
+&\frac{2 \left(\text{tr} \left(\text{e}^4 \left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \left(\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \bar{K}+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}{\left(\bar{K}^2-m_e^2\right).\left(\left(\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}+\\
+&\frac{2 \left(\text{tr} \left(\text{e}^4 \left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_2\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }^*\left(\text{q}_1\right)\right).\left(\bar{\gamma }\cdot \left(\overline{\text{k}_2}+\bar{K}\right)+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_2\right)\right).\left(\bar{\gamma }\cdot \bar{K}+m_e\right).\left(\bar{\gamma }\cdot \bar{\varepsilon }\left(\text{k}_1\right)\right)\right)\right)}{\left(\bar{K}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}\right){}^2-m_e^2\right).\left(\left(\overline{\text{k}_2}+\bar{K}-\overline{\text{q}_1}-\overline{\text{q}_2}\right){}^2-m_e^2\right)}
\end{align*}

\end{frame}

\end{document}


• "Not sure how useful this is" -- really? :-) – Mico Mar 8 '17 at 17:37
• @Mico I hope the main points of the question are fulfilled. I split the lines where it did not course any mathematical problems and adjusted the size, but now the font is so small it could easily been replaced with lorem lipsum -- but that's not my problem :) – samcarter_is_at_topanswers.xyz Mar 8 '17 at 17:46
• I was just giving you a hard time. :-) – Mico Mar 8 '17 at 17:52
• when I see such (long) equation, I lost all will to read it :-( – Zarko Mar 8 '17 at 18:00
• @Mico And I just wanted to whine that the look is not my fault :) – samcarter_is_at_topanswers.xyz Mar 8 '17 at 18:03