Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Expanding horizons: Multipoles and the Symmetry Group   It is well-known that blackhole and cosmological horizons in equilibrium
situations are well-modeled by non-expanding horizons (NEHs). In the first part
of the paper we introduce multipole moments to characterize their geometry,
removing the restriction to axisymmetric situations made in the existing
literature. We then show that the symmetry group $\mathfrak{G}$ of NEHs is a
1-dimensional extension of the BMS group $\mathfrak{B}$. These symmetries are
used in a companion paper to define charges and fluxes on NHEs, as well as
perturbed NEHs. They have physically attractive properties. Finally, it is
generally not appreciated that $\mathcal{I}^\pm$ of asymptotically flat
space-times are NEHs in the conformally completed space-time. Forthcoming
papers will (i) show that $\mathcal{I}^\pm$ have a small additional structure
that reduces $\mathfrak{G}$ to the BMS group $\mathfrak{B}$, and the BMS
charges and fluxes can be recovered from the NEH framework; and, (ii) develop
gravitational wave tomography for the late stage of compact binary
coalescences: reading-off the dynamics of perturbed NEHs in the strong field
regime (via evolution of their multipoles), from the waveform at
$\mathcal{I}^+$.

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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: physics
1
The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg