Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large-scale tidal fields on primordial density perturbations ?   We calculate the strength of the tidal field produced by the large-scale
density field acting on primordial density perturbations in power law models.
By analysing changes in the orientation of the deformation tensor, resulted
from smoothing the density field on different mass scales, we show that the
large-scale tidal field can strongly affect the morphology and orientation of
density peaks. The measure of the strength of the tidal field is performed as a
function of the distance to the peak and of the spectral index. We detected
evidence that two populations of perturbations seems to coexist; one, with a
misalignment between the main axes of their inertia and deformation tensors.
This would lead to the angular momentum acquisition and morphological changes.
For the second population, the perturbations are found nearly aligned in the
direction of the tidal field, which would imprint them low angular momentum and
which would allow an alignment of structures as those reported between clusters
of galaxies in filaments, and between galaxies in clusters. Evidence is
presented that the correlation between the orientation of perturbations and the
large-scale density field could be a common property of Gaussian density fields
with spectral indexes $n < 0$. We argue that alignment of structures can be
used to probe the flatness of the spectrum on large scales but it cannot
determine the exact value of the spectral index.

27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
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The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat