Should I talk about research done in a different field from the department I apply to? As is, I am applying to CS grad school even though I studied math in undergrad and all my research is in math.
The question is, in my personal statement, how sensible is it to talk in depth about my math research? 


Seemingly pro? : Grad schools want to see "research potential" and talking about publishing as a undergrad should help me.
Seemingly con: My CS interests as far afield from my math research so it doesn't seem to make much sense babbling about something unrelated to the field I want to go into. But if this is the case, I don't have much to write about for my POS.
You should talk about the research at least a little. Math research and CS research are very similar in many ways, so the capability to do one is helpful. How much to talk about is trickier and should be something you should discuss with your adviser and others who are more directly familiar with your research itself.