\field = \varphi, \profile = f.
Li and Rb
Added label, just to establish convention.
Fixed the reference commands.
Fixed hyperref
Clarified intro.
Filled in quite a bit of the first section.
Typo:  feschbach --> feshbach
feshbach review
feshbach's original papers.
Cited feshbach's papers, added review.
Point out that an experimenter can turn on phase separation.
Added references folder, seeded with some pdfs.
Explained diluteness expansion.
#Li is large --> ignore #/Phase uncertainty.
Paragraph about mean-field.
On the radial profile.
Solve by minimizing energy
String thickness ~ 1/ sqrt{8 pi a n}.
delta ~ INVERSE of that square root.
Added string thickness estimate.