Review Alba decentralised algorithm

[rrtoledo]

This issue aims at ensuring that the implemented algorithm has been implemented correctly.
The task consists in:

• reviewing the code
• fixing any bug, comments
• writing down todos for future optimizations and refactorization

p.s. right now, there is a mu function to compute the minimal mu given some parameters, we should also allow the user to do the opposite (compute minimal parameters given mu).