How to enter Greek characters in Emacs

You can set your input method to Greek:

M-x set-input-method RET greek

or

C-x RET C-\ greek

(which is the same). To set the input method back press C-\ (toggle-input-method).

M-x set-input-method RET TeX will allow you to write e.g. \beta to get β, \sum or \Sigma to get Σ etc.

It can be toggled on and off with toggle-input-method, bound to C-\ and C-<.

You can use ucs-insert bound to C-x8RET to insert any Unicode characters by name or by value.

For example to insert a lambda you can do

• C-x8RET GREEK SMALL LETTER LAMBDA RET → λ
• C-x8RET 03bb RET → λ

A tab-completion is also available.

C-x8RET* lambdaTAB will list every unicode characters ended by a lambda.