Writing Lines and Lines of Math Without Continuation Characters

Question

I've recently converted to using \[ \] instead of $$ $$ as my begin/end math command since I read that is the "correct" method. However, the backslash character is near my pinky on my keyboard and typing that every single line is getting my pinky fatigued.

Is there some sort of multiline equation command/environment in LaTeX similar to how many programming languages have multiline comments?

That is, I currently have:

\[ r \approx R_{\odot}/2 \]
\[ T \approx 10^{7} K \]
\[ M \approx \frac{1}{2} M_{\odot} \]
\[ l \approx R_{\odot}/20 \]
\[ H = \frac{L_{\odot}}{4 \pi r^{2}} \]
\[ \Delta \nabla T \approx 2 \times 10^{-10} \]
\[ \frac{dT}{dr} \approx \frac{\bar{T}}{R_{\odot}} \approx 6 \times 10^{-5} \]

whereas I would like something of the form

\begin{math}
r \approx R_{\odot}/2
T \approx 10^{7} K
M \approx \frac{1}{2} M_{\odot}
l \approx R_{\odot}/20
H = \frac{L_{\odot}}{4 \pi r^{2}}
\Delta \nabla T \approx 2 \times 10^{-10}
\frac{dT}{dr} \approx \frac{\bar{T}}{R_{\odot}} \approx 6 \times 10^{-5}
\end{math}

Please note that amsmath's align and gather don't fit the bill for me since they require two backslashes at the end of each line.

I'm open to source modification solutions.

Also, I'm using the article documentclass (if it matters).

Answer 1

I think gathered can help you

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{equation}
    \begin{gathered}
        r \approx R_{\odot}/2 \\
        T \approx 10^{7} K \\
        M \approx \frac{1}{2} M_{\odot} \\
        l \approx R_{\odot}/20 \\
        H = \frac{L_{\odot}}{4 \pi r^{2}} \\
        \Delta \nabla T \approx 2 \times 10^{-10} \\
        \frac{dT}{dr} \approx \frac{\bar{T}}{R_{\odot}} \approx 6 \times 10^{-5}
    \end{gathered}
\end{equation}

\end{document}

I do agree with comments because \\ are necessary in LaTeX. You will take the habits :)

Answer 2

This solves two problems at once: first, not typing \[...\] over and over, and second, having a neat alignment. Try using the align env:

    \begin{align}
        r \approx R_{\odot}/2 \\
        T \approx 10^{7} K \\
        M \approx \frac{1}{2} M_{\odot} \\
        l \approx R_{\odot}/20 \\
        H = \frac{L_{\odot}}{4 \pi r^{2}} \\
        \Delta \nabla T \approx 2 \times 10^{-10} \\
        \frac{dT}{dr} \approx \frac{\bar{T}}{R_{\odot}} \approx 6 \times 10^{-5} \\
    \end{align}

Now, insert the & symbol where you want it to align. This creates a very nice arrangement! For example, why not try this:

    \begin{align}
        &r \approx R_{\odot}/2 \\
        &T \approx 10^{7} K \\
        &M \approx \frac{1}{2} M_{\odot} \\
        &l \approx R_{\odot}/20 \\
        &H = \frac{L_{\odot}}{4 \pi r^{2}} \\
        &\Delta \nabla T \approx 2 \times 10^{-10} \\
        &\frac{dT}{dr} \approx \frac{\bar{T}}{R_{\odot}} \approx 6 \times 10^{-5} \\
    \end{align}

This will align everything on the left. Put all the &s to the right for a right align, or mix things up by adding &s in the middle. In general, all equations will shift until the &s line up, then hide the &s.