Tau (τ) in LaTeX
In LaTeX maths mode, \tau produces the lowercase Greek letter tau (τ). Uppercase Tau is identical to a Latin capital T, so there is no \Tau command.
LaTeX command
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Tau, \tau, is common across physics and statistics. It denotes a time constant in decaying and charging systems, a torque in mechanics, the proper time in relativity, and a shear stress in continuum mechanics. In statistics Kendall's tau is a rank correlation coefficient, and in particle physics \tau labels the tau lepton.
Tau also names the constant 2\pi (approximately 6.28318) in the tau-versus-pi convention, where a full turn is \tau radians. Whatever the meaning, \tau must be used in maths mode and is italic by default, the standard style for a variable or constant.
There is no uppercase command, since the capital Greek Tau is drawn as a Roman T; type T, or \mathrm{T} for an upright roman capital. In subscripts tau behaves like any symbol, for example a relaxation time \tau_r or the tau neutrino \nu_\tau.
Other forms
\taulowercase tauExamples
$\tau$lowercase tau inline
$V(t) = V_0\,e^{-t/\tau}$exponential decay with time constant tau
$\tau = r F \sin\theta$the magnitude of a torque
$\tau = 2\pi$the tau constant, a full turn in radians
Tips and common mistakes
- There is no
\Tau; uppercase Greek Tau is a Latin T, so type T, or\mathrm{T}for upright. \tauis maths-mode only; wrap it in .- For a bold tau use
\boldsymbol{\tau}, not\mathbf, which does not bold lowercase Greek letters. - There is no variant form; only
\tauexists for this letter. - In subscripts tau works like any symbol, for example a relaxation time
\tau_r.
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Convert your maths to LaTeX →FAQ
Is there a capital tau command in LaTeX?
No. Uppercase Greek Tau is identical to the Latin T, so LaTeX has no \Tau; type T, or \mathrm{T} for an upright capital.
How do I write a time constant with tau?
Use \tau in an exponential, for example , where tau is the time constant of the decay.
What does tau mean in statistics?
Kendall's tau (τ) is a rank correlation coefficient measuring the ordinal association between two variables.