Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark-dark-soliton dynamics in two density-coupled Bose-Einstein
  condensates   We study the 1D dynamics of dark-dark solitons in the miscible regime of two
density-coupled Bose-Einstein condensates having repulsive interparticle
interactions within each condensate ($g>0$). By using an adiabatic perturbation
theory in the parameter $g_{12}/{g}$, we show that, contrary to the case of two
solitons in scalar condensates, the interactions between solitons are
attractive when the interparticle interactions between condensates are
repulsive $g_{12}>0$. As a result, the relative motion of dark solitons with
equal chemical potential $\mu$ is well approximated by harmonic oscillations of
angular frequency $w_r=(\mu/\hbar)\sqrt{({8}/{15}){g_{12}}/{g}}$. We also show
that in finite systems, the resonance of this anomalous excitation mode with
the spin density mode of lowest energy gives rise to alternating dynamical
instability and stability fringes as a function of the perturbative parameter.
In the presence of harmonic trapping (with angular frequency $\Omega$) the
solitons are driven by the superposition of two harmonic motions at a frequency
given by $w^2=(\Omega/\sqrt{2})^2+w_r^2$. When $g_{12}<0$, these two
oscillators compete to give rise to an overall effective potential that can be
either single well or double well through a pitchfork bifurcation. All our
theoretical results are compared with numerical solutions of the
Gross-Pitaevskii equation for the dynamics and the Bogoliubov equations for the
linear stability. A good agreement is found between them.

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The categories of this paper are: adap-org
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
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The categories of this paper are: econ
27
The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph