Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Seismic evidence for a rapidly rotating core in a lower-giant-branch
  star observed with Kepler   Rotation is expected to have an important influence on the structure and the
evolution of stars. However, the mechanisms of angular momentum transport in
stars remain theoretically uncertain and very complex to take into account in
stellar models. To achieve a better understanding of these processes, we
desperately need observational constraints on the internal rotation of stars,
which until very recently were restricted to the Sun. In this paper, we report
the detection of mixed modes - i.e. modes that behave both as g modes in the
core and as p modes in the envelope - in the spectrum of the early red giant
KIC7341231, which was observed during one year with the Kepler spacecraft. By
performing an analysis of the oscillation spectrum of the star, we show that
its non-radial modes are clearly split by stellar rotation and we are able to
determine precisely the rotational splittings of 18 modes. We then find a
stellar model that reproduces very well the observed atmospheric and seismic
properties of the star. We use this model to perform inversions of the internal
rotation profile of the star, which enables us to show that the core of the
star is rotating at least five times faster than the envelope. This will shed
new light on the processes of transport of angular momentum in stars. In
particular, this result can be used to place constraints on the angular
momentum coupling between the core and the envelope of early red giants, which
could help us discriminate between the theories that have been proposed over
the last decades.

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The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin