Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inside the Final Black Hole: Puncture and Trapped Surface Dynamics   A popular approach in numerical simulations of black hole binaries is to
model black holes as punctures in the fabric of spacetime. The location and the
properties of the black hole punctures are tracked with apparent horizons,
namely outermost marginally outer trapped surfaces (MOTSs). As the holes
approach each other, a common apparent horizon suddenly appears, engulfing the
two black holes and signaling the merger. The evolution of common apparent
horizons and their connection with gravitational wave emission have been
studied in detail with the framework of dynamical horizons. We present a study
of the dynamics of the MOTSs and their punctures in the interior of the final
black hole. The study focuses on head-on mergers for various initial
separations and mass ratios. We find that MOTSs intersect for most of the
parameter space. We show that for those situations in which they do not, it is
because of the singularity avoidance property of the moving puncture gauge
condition used in the study. Although we are unable to carry out evolutions
that last long enough to show the ultimate fate of the punctures, our results
suggest that MOTSs always intersect and that at late times their overlap is
only partial. As a consequence, the punctures inside the MOTSs, although close
enough to each other to act effectively as a single puncture, do not merge.

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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-th
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The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin