# How can I use German umlauts in DeclareMathOperator?

I would like to define a math operator Homöo, but when I try

\DeclareMathOperator{\Homoo}{Homöo}
\DeclareMathOperator{\Homoo}{Hom\"oo}


I get Homo.

How can I use German umlauts in DeclareMathOperator?

(If it's not possible at all: What should I do instead?)

The text in the second argument of \DeclareMathOperator is typeset in a special variety of \mathrm, so - produce a hyphen, for instance, not a minus sign. Fragments of words like yours can be dealt with by saying
\DeclareMathOperator{\Homoo}{\textnormal{Homöo}}

• @moose Moreover, you should use \textnormal if you need kerning in the operator. I recently needed it for the variance to get correct kerning between V and a: \DeclareMathOperator{\Var}{\textnormal{Var}}. Jan 13 '14 at 23:27
• @moose I just wrote an example, if you use \DeclareMathOperator{\Var}{Var} and compare it with the one I used, you will see the difference, the V letter has space under it to put the lowercase a. There is no general rule for kerning, you need it when two letters can be kerned. Jan 14 '14 at 11:17
• @Manuel, I was asking the other way around: Is there any reason not to use \textnormal? Jan 14 '14 at 12:24
• @Manuel I get no difference between \operatorname{Var} and \operatorname{\textnormal{Var}} Jan 14 '14 at 12:34