Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality, frustration and conformal invariance in two-dimensional
  random Ising magnets   We consider long, finite-width strips of Ising spins with randomly
distributed couplings. Frustration is introduced by allowing both ferro- and
antiferromagnetic interactions. Free energy and spin-spin correlation functions
are calculated by transfer-matrix methods. Numerical derivatives and
finite-size scaling concepts allow estimates of the usual critical exponents
$\gamma/\nu$, $\alpha/\nu$ and $\nu$ to be obtained, whenever a second-order
transition is present. Low-temperature ordering persists for suitably small
concentrations of frustrated bonds, with a transition governed by pure--Ising
exponents. Contrary to the unfrustrated case, subdominant terms do not fit a
simple, logarithmic-enhancement form. Our analysis also suggests a vertical
critical line at and below the Nishimori point. Approaching this point along
either the temperature axis or the Nishimori line, one finds non-diverging
specific heats. A percolation-like ratio $\gamma/\nu$ is found upon analysis of
the uniform susceptibility at the Nishimori point. Our data are also consistent
with frustration inducing a breakdown of the relationship between
correlation-length amplitude and critical exponents, predicted by conformal
invariance for pure systems.

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The categories of this paper are: cs
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-lat
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The categories of this paper are: eess