The name is absent

and the average solvent density is given as, (ps(y))_w+,w-, where

^ / r∙ , n <HnQ_s[⅛,₊ + w_]

_z⅛⅛₊ + u>-]) = →⅛ ^_wt+w-∣  ■          (8 3S)

Clearly, there are two important aspects for particle-to-field transformation. One
is the introduction of the auxiliary chemical potential ^lw^, fields that serve to decouple
the interaction among the molecules, replacing them with the interactions between
each molecule and the field variables. The second aspect and the advantage of such
a transformation is that the resulting field theory sidesteps the many-body problem
- only the partition function of the (ə[w] of a single polymer or solvent molecule
experiencing the auxiliary fields need to be computed.

8.3 Formalism of self-consistent field theory

The field-theoretic models express the relevant partition function as a functional
integral over one or more chemical potential fields, w(r),

Z — J Dw exp(-7∕[w]).                     (8.37)

The observable properties are calculated as an ensemble average,

(G[w]) = Z~¹ [ Dw G[w] exp (—H[w]).               (8.38)

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