By default \citeauthor
uses the labelname
format. With your set-up you could simply use
\DeclareNameAlias{labelname}{given-family}
That works well since you don't use the labelname
format in citations (your style is alphabetic
) and you already have giveninits=true
(giveninits
was called firstinits
in older versions) so we only ever get initials.
With other styles that use labelname
you might need
\DeclareCiteCommand{\citeauthor}
{\boolfalse{citetracker}%
\boolfalse{pagetracker}%
\usebibmacro{prenote}}
{\ifciteindex
{\indexnames{labelname}}
{}%
\printnames[given-family]{labelname}}
{\multicitedelim}
{\usebibmacro{postnote}}
instead.
If you don't have giveninits=true
enabled, use
\DeclareNameFormat{g-family}{%
\usebibmacro{name:given-family}
{\namepartfamily}
{\namepartgiveni}
{\namepartprefix}
{\namepartsuffix}%
\usebibmacro{name:andothers}}
\DeclareCiteCommand{\citeauthor}
{\boolfalse{citetracker}%
\boolfalse{pagetracker}%
\usebibmacro{prenote}}
{\ifciteindex
{\indexnames{labelname}}
{}%
\printnames[g-family]{labelname}}
{\multicitedelim}
{\usebibmacro{postnote}}