Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effects of Dark Energy anisotropic stress on the matter power spectrum   We study the effects of dark energy (DE) anisotropic stress on features of
the matter power spectrum (PS). We employ the Parametrized Post-Friedmannian
(PPF) formalism to emulate an effective DE, and model its anisotropic stress
properties through a two-parameter equation that governs its overall amplitude
($g_0$) and transition scale ($c_g$). For the background cosmology, we consider
different equations of state to model DE including a constant $w_0$ parameter,
and models that provide thawing (CPL) and freezing (nCPL) behaviors. We first
constrain these parameters by using the Pantheon, BAO, $H_0$ and CMB Planck
data. Then, we analyze the role played by these parameters in the linear PS. In
order for the anisotropic stress not to provoke deviations larger than $10\%$
and $5\%$ with respect to the $\Lambda$CDM PS at $k \sim 0.01 \,h/\text{Mpc}$,
the parameters have to be in the range $-0.30< g_0 < 0.32$, $0 \leq c_g^2 <
0.01$ and $-0.15 < g_0 < 0.16$, $0 \leq c_g^2 < 0.01$, respectively.
Additionally, we compute the leading nonlinear corrections to the PS using
standard perturbation theory in real and redshift space, showing that the
differences with respect to the $\Lambda$CDM are enhanced, especially for the
quadrupole and hexadecapole RSD multipoles.

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The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
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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: patt-sol
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
21
The categories of this paper are: adap-org