Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Fermion Sign Problem and High Density Effective Theory   We investigate the positivity of the Euclidean path integral measure for
low-energy modes in dense fermionic matter. We show that the sign problem
usually associated with fermions is absent if one considers only low-energy
degrees of freedom. We describe a method for simulating dense QCD on the
lattice and give a proof using rigorous inequalities that the color-flavor
locked (CFL) phase is the true vacuum of three flavor, massless QCD.

15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
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The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph