Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polynomial method for canonical calculations   A practical version of the polynomial canonical formalism is developed for
normal mesoscopic systems consisting of N independent electrons. Drastic
simplification of calculations is attained by means of proper ordering excited
states of the system. In consequence the exact canonical partition function can
be represented as a series in which the first term corresponds to the ground
state whereas successive groups of terms belong to many particle-hole
excitations (one particle-hole two particle-hole and so on). At small
temperatures (T<10 inter-level spacings near the Fermi level) the number of
terms which should be taken into account is weakly dependent on N and remains
<10 even if N~100000. The elaborated method makes canonical calculations to be
not more complicated than the grand canonical ones and is free from any
limitations on N and T.

22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an