mathcal e lettere minuscole

`\mathpzc{ABCdef123}`

Put \\DeclareMathAlphabet{\mathpzc}{OT1}{pzc}{m}{it}” in your document’s
preamble to make \mathpzc typeset its argument in Zapf Chancery.
As a similar trick, you can typeset the Calligra font’s script \ r ” (or other
calligraphic symbols) in math mode by loading the calligra package and
putting \\DeclareMathAlphabet{\mathcalligra}{T1}{calligra}{m}{n}”
in your document’s preamble to make \mathcalligra typeset its
argument in the Calligra font. (You may also want to specify
\\DeclareFontShape{T1}{calligra}{m}{n}{<->s*[2.2]callig15}{}” to
set Calligra at 2.2 times its design size for a better blend with typical body fonts.)

Pagina 65 della Comprehensive List.

Ciao,
L.