Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black Holes: A Window into A New Theory of Space Time   S. Chandrasekhar wrote in the prologue to his book on black holes, "The black
holes of nature are the most perfect macroscopic objects there are in the
universe: the only elements in their construction are our concepts of space and
time." In this contribution I briefly discuss recent developments in
fundamental theory and black holes that vindicate this statement in a modern
perspective. I also include some of my reminiscences of Chandra.

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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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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: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph