Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermalization and Revivals after a Quantum Quench in Conformal Field
  Theory   We consider a quantum quench in a finite system of length $L$ described by a
1+1-dimensional CFT, of central charge $c$, from a state with finite energy
density corresponding to an inverse temperature $\beta\ll L$. For times $t$
such that $\ell/2<t<(L-\ell)/2$ the reduced density matrix of a subsystem of
length $\ell$ is exponentially close to a thermal density matrix. We compute
exactly the overlap $\cal F$ of the state at time $t$ with the initial state
and show that in general it is exponentially suppressed at large $L/\beta$.
However, for minimal models with $c<1$ (more generally, rational CFTs), at
times which are integer multiples of $L/2$ (for periodic boundary conditions,
$L$ for open boundary conditions) there are (in general, partial) revivals at
which $\cal F$ is $O(1)$, leading to an eventual complete revival with ${\cal
F}=1$. There is also interesting structure at all rational values of $t/L$,
related to properties of the CFT under modular transformations. At early times
$t\!\ll\!(L\beta)^{1/2}$ there is a universal decay ${\cal
F}\sim\exp\big(\!-\!(\pi c/3)Lt^2/\beta(\beta^2+4t^2)\big)$. The effect of an
irrelevant non-integrable perturbation of the CFT is to progressively broaden
each revival at $t=nL/2$ by an amount $O(n^{1/2})$.

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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: physics
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga