Lambda (Upper) in LaTeX (\Lambda)

Where it is used

Uppercase Greek Lambda, common for diagonal eigenvalue matrices and the cosmological constant.

The spectral decomposition A = Q\Lambda Q^{-1} uses \Lambda for the diagonal matrix of eigenvalues. Cosmology writes the cosmological constant as \Lambda, and the standard model of cosmology is typeset \Lambda\text{CDM}. Particle physics uses it for the Lambda baryon, and lattice theory or number theory may use \Lambda for a lattice or the von Mangoldt function \Lambda(n). Capital Greek is upright in LaTeX; use \varLambda for an italic form. Do not mistake it for the logical and \wedge, which is a different, operator-spaced glyph.

Minimal compilable example

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

\documentclass{article}
\usepackage{amsmath}
\begin{document}
Lambda (Upper): $\Lambda$

\[ A = Q \Lambda Q^{-1}, \quad \Lambda = \operatorname{diag}(\lambda_i) \]
\end{document}

Related symbols

• Mu\mu
• Lambda\lambda
• Nu\nu
• Kappa\kappa
• Xi\xi
• Iota\iota

Frequently asked questions

How do I write Lambda (Upper) in LaTeX?

Type \Lambda in math mode, for example $A = Q \Lambda Q^{-1}, \quad \Lambda = \operatorname{diag}(\lambda_i)$. It works in plain LaTeX without loading any package.

Which package do I need for \Lambda?

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

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

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