The LaTeX command for mathcal L (ℒ) is \mathcal{L} (Lagrangian / Laplace transform).
\mathcal{L}Writing a paper? The table generator and the BibTeX cleaner are one click away, no account.
| Command | Package | Use it when |
|---|---|---|
\mathcal{L} recommended | none | Lagrangian, loss function, Laplace transform. |
\mathscr{L} | mathrsfs | Script L, more ornate. |
\ell | none | Script lowercase l, e.g. a loss per example. |
\mathcal{L}(\theta) | none | A loss as a function of the parameters. |
Write \mathcal{L} inside math mode, that is between $…$ for inline math or in a \[ … \] or equation block for display math. It is part of core LaTeX math, so no extra package is required.
$\mathcal{L}(\theta) = -\sum_{i=1}^{n} \log p_\theta(x_i)$Open this example in the live preview: it renders as you type, with no compiler and no signup.
\angle\measuredangle\triangle\diamond\bigodot\bigoplus\bigotimes\mathcal{H}\mathcal{F}\mathcal{A}\mathcal{B}\mathcal{C}\mathcal{D}\mathcal{G}More math symbols in LaTeX: the full table or search all 350+ LaTeX symbols.
Use \mathcal{L} in math mode; it needs no extra package. For example, $\mathcal{L}(\theta) = -\sum_{i=1}^{n} \log p_\theta(x_i)$.
None: \mathcal{L} is built into LaTeX, so no extra package is required.
\mathcal only has capitals: \mathcal{l} prints a wrong glyph. For a lowercase script l use \ell.