Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Binding Energy Parameter $\lambda$ of Common Envelope Evolution   The binding energy parameter $\lambda$ plays an important role in common
envelope (CE) evolution. Previous works have already pointed out that $\lambda$
varies throughout the stellar evolution, though it has been adopted as a
constant in most of the population synthesis calculations. We have
systematically calculated the binding energy parameter $\lambda$ for both
Population I and Population II stars of masses $1-20 M_{\sun}$, taking into
account the contribution from the internal energy of stellar matter. We present
fitting formulae for $\lambda$ that can be incorporated into future population
synthesis investigations. We also briefly discuss the possible applications of
the results in binary evolutions.

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The categories of this paper are: cs
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: quant-ph
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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: math
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga