Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Numerical Models of Travel-Time Inhomogeneities in Sunspots   We investigate the direct contribution of strong, sunspot-like magnetic
fields to helioseismic wave travel-time shifts via two numerical forward
models, a 3D ideal MHD solver and MHD ray theory. The simulated data cubes are
analyzed using the traditional time-distance center-to-annulus measurement
technique. We also isolate and analyze the direct contribution from purely
thermal perturbations to the observed travel-time shifts, confirming some
existing ideas and bring forth new ones: (i) that the observed travel-time
shifts in the vicinity of sunspots are largely governed by MHD physics, (ii)
the travel-time shifts are sensitively dependent on frequency and phase-speed
filter parameters and the background power below the $p_1$ ridge, and finally,
(iii) despite its seeming limitations, ray theory succeeds in capturing the
essence of the travel-time variations as derived from the MHD simulations.

12
The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat