# How can I write a cursive letter k in math?

Using amsmath, writing $\ell$ produces a cursive lowercase letter l. I would like to have a reasonably matching cursive lowercase letter k, available through \kay e.g., so that I can write things like $\kay,\ell \in S$.

Is this possible?

• \ell is not cursive. It has a loop to help diferentiate over other letters or symbols in math that may cause confusion. What you need is look for a font (probably script font) that has lowercase letters. – Manuel Nov 21 '14 at 22:42
• Related/duplicate tex.stackexchange.com/questions/211462/… – egreg Nov 21 '14 at 23:49

If you are happy to use the Stix fonts, you could try this:

\documentclass{article}
\usepackage{stix}
\begin{document}
A script k in maths $\mathscr k$
\end{document}


Otherwise you need to find a maths font that implements the Unicode character: 𝓀 or "MATHEMATICAL SCRIPT SMALL K" which is Unicode code point U+1D4C0, and compile with xelatex or lualatex.

Run with xelatex

\documentclass{article}
\usepackage{amsmath}
\usepackage{unicode-math}
\setmathfont{STIX Math}
\def\kay{\ensuremath{\mscrk}}
\begin{document}
$\ell$ and $\kay$ and $\mscrl$
\end{document}