Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pulsar braking and the P-Pdot diagram   The location of radio pulsars in the period-period derivative (P-Pdot) plane
has been a key diagnostic tool since the early days of pulsar astronomy. Of
particular importance is how pulsars evolve through the P-Pdot diagram with
time. Here we show that the decay of the inclination angle (alpha-dot) between
the magnetic and rotation axes plays a critical role. In particular, alpha-dot
strongly impacts on the braking torque, an effect which has been largely
ignored in previous work. We carry out simulations which include a negative
alpha-dot term, and show that it is possible to reproduce the observational
P-Pdot diagram without the need for either pulsars with long birth periods or
magnetic field decay. Our best model indicates a birth rate of 1 radio pulsar
per century and a total Galactic population of ~20000 pulsars beaming towards
Earth.

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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ph
1
The categories of this paper are: cs