Quote by physiker_192
Hello,
I am not sure I can help here, but I think those two might be worth looking at:
1. Financial Engineering ( a subfield of Finance/Economics & Mathematics).
2. Econophysics (a subfield of physics)

Thank you. I wasn't aware of Econophysics and looks interesting:
http://en.wikipedia.org/wiki/Econophysics
I can see Statistical Physics is important.
Quote by doodle_sack
Hi Artus, Mathematical Economics is not a separate branch of Economics like Macroeconomics, Microeconomics, International Trade, etc. It is just a way of economic analysis, where the mathematical proofs and theorems are used heavily to make the economic models, for instance Ct + It = Yt = F(Kt,L), It = Kt+1  (1δ)Kt, It = sF(Kt,L) is the most fundamental model in macroeconomics called the Solow's Growth Model, which was build upon using mathematics, thus it can be called as mathematical economics, eventually economic analysis.
If you are interested doing research in this area i would higly recommend you to visit this site http://econ.lse.ac.uk/study/grpr.html that is the bestintheworld economics graduate program in that specific area which would help you get into an elite PhD program anywhere in the world. But you must know that unlike Physics or other Science fields, in economics you can do research in any area of your fancy if you have a good bachelors degree in economics(with a very good math courses in it) and a graduate program in some cases.
And yes, science students do very well in Economics graduate programs, especially Physicists and Engineers.
Good luck, PM me if you need any help!!

Thank you. LSE looks great and from the link you gave us I can see the have a great Mathematics department. And yes, models like Solow's get my interest becaude their mathematical nature and economical application.
Maybe I'm gonna look for a Master in Economics and after that a PhD in Economics, Mathematics or Applied Mathematics.