Question

What is the speed of sound in plasma and Bose Einstein condensate?

Answer 1

In a plasma it's just \[c_s = \sqrt{\frac{\gamma \, Z \, k \, T_e}{m_i}}\] see: http://en.wikipedia.org/wiki/Plasma_parameters#Velocities

For Bose-Einstein Condensates, the thing is not quite as easy... take a look at this: http://arxiv.org/pdf/1205.4774v1.pdf

(haven't read it myself, just skipped over - if it's not what you're asking, I'm sorry)