Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sum rule analysis of Umklapp processes and Coulomb energy: application
  to cuprate superconductivity   The third moment frequency sum rule for the density-density correlation
function is rederived in the presence of Umklapp processes. Upper and lower
bounds on the electron-electron Coulomb energy are derived in two-dimensional
and three-dimensional media, and the Umklapp processes are shown to be crucial
in determining the spectrum of the density fluctuations (especially for the
two-dimensional systems). This and other standard sum rules can be used in
conjunction with experimental spectroscopies (electron-energy loss
spectroscopy, optical ellipsometry, etc.) to analyse changes of the
electron-electron Coulomb energy at the superconducting transition in cuprates.

37
The categories of this paper are: supr-con
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph