Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Excitation Spectrum of Composite Fermions   We show that the excitation spectrum of interacting electrons at filling
factor $\nu=\nu^*/(2\nu^*+1)$ is well described in terms of non-interacting
composite fermions at filling factor $\nu^*$, but does not have a one-to-one
correspondence with the excitation spectrum of non-interacting electrons at
$\nu^*$. In particular, the collective modes of the fractional quantum Hall
states are not analogous to those of the integer quantum Hall states. We also
speculate on the nature of the compressible state at $\nu=1/2$.

26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ