Arial font in mathtext

Dear all,

I'm trying to set the font for math elements in my plots to 'Arial' when
saving my plot to an eps. For all other text in plots, I set


and it worked. My default rcparams for mathtext look like this:

'': 'serif:bold',
'': 'cursive',
'mathtext.default': 'it',
'mathtext.fallback_to_cm': True,
'mathtext.fontset': 'cm',
'': 'serif:italic',
'mathtext.rm': 'serif',
'mathtext.sf': 'sans\\-serif',
'': 'monospace',

I do not quite understand all these parameters and could not find it out
in the ocumentation.
Is there an easy way to ensure that all text (normal and mathtext) I put
in my plots appear in Arial?
If not, is at least the font of mathtext embedded into the eps?

Hope I made my problem clear,
thanks in advance,