Upsilon in LaTeX (\upsilon)

Where it is used

Lowercase Greek upsilon, a rarely used letter that closely resembles the Latin u or v.

Lowercase \upsilon is uncommon in mathematics, largely because it is easily confused with u and with \nu. It appears in particle physics, for the Upsilon meson usually written in uppercase, and occasionally as a velocity or a generic index variable. If you need a new variable, a less ambiguous letter is often a better choice. When you do use it, define it explicitly. LaTeX's \upsilon is italic like other lowercase Greek letters, while the capital \Upsilon has its own command.

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\begin{document}
Upsilon: $\upsilon$

\[ \upsilon(t) = \frac{dx}{dt}, \quad x(t) = \int_0^t \upsilon(s)\,ds \]
\end{document}

Related symbols

• Upsilon (Upper)\Upsilon
• Tau\tau
• Phi\phi
• Sigma (Upper)\Sigma
• Phi (Upper)\Phi
• Sigma\sigma

Frequently asked questions

How do I write Upsilon in LaTeX?

Type \upsilon in math mode, for example $\upsilon(t) = \frac{dx}{dt}, \quad x(t) = \int_0^t \upsilon(s)\,ds$. It works in plain LaTeX without loading any package.

Which package do I need for \upsilon?

None. \upsilon is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \upsilon in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\upsilon$ in running text. If you only need the glyph in text, paste the Unicode character υ instead (with XeLaTeX or LuaLaTeX and a font that has it).