scholarly journals The S8 tension in light of updated redshift-space distortion data and PAge approximation

2022 ◽  
Vol 65 (3) ◽  
Author(s):  
Lu Huang ◽  
Zhiqi Huang ◽  
Huan Zhou ◽  
Zhuoyang Li
Keyword(s):  
Space Distortion

scholarly journals Testing the effect of H0 on fσ8 tension using a Gaussian Process method

2020 ◽  
Author(s):  
En-Kun Li ◽  
Minghui Du ◽  
Zhi-Huan Zhou ◽  
Hongchao Zhang ◽  
Lixin Xu
Keyword(s):  
Growth Rate ◽  
Dark Energy ◽  
Cosmological Constant ◽  
Gaussian Process ◽  
Dark Energy Model ◽  
Hubble Space Telescope ◽  
Λcdm Model ◽  
Space Distortion ◽  
Best Fit ◽  
Process Method

Abstract Using the fσ8(z) redshift space distortion (RSD) data, the $\sigma _8^0-\Omega _m^0$ tension is studied utilizing a parameterization of growth rate f(z) = Ωm(z)γ. Here, f(z) is derived from the expansion history H(z) which is reconstructed from the observational Hubble data applying the Gaussian Process method. It is found that different priors of H0 have great influences on the evolution curve of H(z) and the constraint of $\sigma _8^0-\Omega _m^0$. When using a larger H0 prior, the low redshifts H(z) deviate significantly from that of the ΛCDM model, which indicates that a dark energy model different from the cosmological constant can help to relax the H0 tension problem. The tension between our best-fit values of $\sigma _8^0-\Omega _m^0$ and that of the Planck 2018 ΛCDM (PLA) will disappear (less than 1σ) when taking a prior for H0 obtained from PLA. Moreover, the tension exceeds 2σ level when applying the prior H0 = 73.52 ± 1.62 km/s/Mpc resulted from the Hubble Space Telescope photometry. By comparing the $S_8 -\Omega _m^0$ planes of our method with the results from KV450+DES-Y1, we find that using our method and applying the RSD data may be helpful to break the parameter degeneracies.

Effects of Gravitational Evolution, Biasing, and Redshift Space Distortion on Topology

2005 ◽  
Vol 633 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Changbom Park ◽  
Juhan Kim ◽  
J. Richard Gott III
Keyword(s):  
Space Distortion

scholarly journals ΛCDM as a Noether symmetry in cosmology

2020 ◽  
Vol 29 (15) ◽  
pp. 2050104 ◽  
Author(s):  
D. Benisty ◽  
E. I. Guendelman ◽  
E. Nissimov ◽  
S. Pacheva
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Noether Symmetry ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Main Ingredient ◽  
Riemannian Spacetime ◽  
Stress Energy ◽  
Space Distortion ◽  
Conserved Current

The standard [Formula: see text]CDM model of cosmology is formulated as a simple modified gravity coupled to a single scalar field (“darkon”) possessing a nontrivial hidden nonlinear Noether symmetry. The main ingredient in the construction is the use of the formalism of non-Riemannian spacetime volume-elements. The associated Noether conserved current produces stress–energy tensor consisting of two additive parts — dynamically generated dark energy and dark matter components noninteracting among themselves. Noether symmetry breaking via an additional scalar “darkon” potential introduces naturally an interaction between dark energy and dark matter. The correspondence between the [Formula: see text]CDM model and the present “darkon” Noether symmetry is exhibited up to linear order with respect to gravity-matter perturbations. With the Cosmic Chronometers (CC) and the Redshift Space Distortion (RSD) datasets, we study an example for the “darkon” potential that breaks the Noether symmetry and we show that the preservation of this symmetry yields a better fit.

scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the quasar sample

2020 ◽  
Vol 499 (1) ◽  
pp. 269-291 ◽  
Author(s):  
Alex Smith ◽  
Etienne Burtin ◽  
Jiamin Hou ◽  
Richard Neveux ◽  
Ashley J Ross ◽  
...  
Keyword(s):  
Final Analysis ◽  
Systematic Errors ◽  
Acoustic Oscillation ◽  
Sloan Digital Sky Survey ◽  
Fourier Space ◽  
Redshift Surveys ◽  
Sky Survey ◽  
History Of ◽  
Space Distortion ◽  
Halo Occupation Distribution

ABSTRACT The growth rate and expansion history of the Universe can be measured from large galaxy redshift surveys using the Alcock–Paczynski effect. We validate the Redshift Space Distortion models used in the final analysis of the Sloan Digital Sky Survey (SDSS) extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 quasar clustering sample, in configuration and Fourier space, using a series of halo occupation distribution mock catalogues generated using the OuterRim N-body simulation. We test three models on a series of non-blind mocks, in the OuterRim cosmology, and blind mocks, which have been rescaled to new cosmologies, and investigate the effects of redshift smearing and catastrophic redshifts. We find that for the non-blind mocks, the models are able to recover fσ8 to within 3 per cent and α∥ and α⊥ to within 1 per cent. The scatter in the measurements is larger for the blind mocks, due to the assumption of an incorrect fiducial cosmology. From this mock challenge, we find that all three models perform well, with similar systematic errors on fσ8, α∥, and α⊥ at the level of $\sigma _{f\sigma _8}=0.013$, $\sigma _{\alpha _\parallel }=0.012$, and $\sigma _{\alpha _\bot }=0.008$. The systematic error on the combined consensus is $\sigma _{f\sigma _8}=0.011$, $\sigma _{\alpha _\parallel }=0.008$, and $\sigma _{\alpha _\bot }=0.005$, which is used in the final DR16 analysis. For baryon acoustic oscillation fits in configuration and Fourier space, we take conservative systematic errors of $\sigma _{\alpha _\parallel }=0.010$ and $\sigma _{\alpha _\bot }=0.007$.

scholarly journals Quantifying the redshift space distortion of the bispectrum I: primordial non-Gaussianity

2020 ◽  
Vol 493 (1) ◽  
pp. 594-602 ◽  
Author(s):  
Somnath Bharadwaj ◽  
Arindam Mazumdar ◽  
Debanjan Sarkar
Keyword(s):  
Spherical Harmonics ◽  
Real Space ◽  
Line Of Sight ◽  
Multipole Moments ◽  
Distortion Parameter ◽  
Redshift Surveys ◽  
Space Distortion ◽  
Zero Values ◽  
Parallel Approximation ◽  
Analytical Expressions

ABSTRACT The anisotropy of the redshift space bispectrum contains a wealth of cosmological information. This anisotropy depends on the orientation of three vectors $\boldsymbol {k_1},\boldsymbol {k_2},\boldsymbol {k_3}$ with respect to the line of sight. Here, we have decomposed the redshift space bispectrum in spherical harmonics which completely quantify this anisotropy. To illustrate this, we consider linear redshift space distortion of the bispectrum arising from primordial non-Gaussianity. In the plane-parallel approximation, only the first four even ℓ multipoles have non-zero values, and we present explicit analytical expressions for all the non-zero multipoles, that is, upto ℓ = 6 and m = 4. The ratio of the different multipole moments to the real-space bispectrum depends only on β1 the linear redshift distortion parameter and the shape of the triangle. Considering triangles of all possible shapes, we have studied how this ratio depends on the shape of the triangle for β1 = 1. We have also studied the β1 dependence for some of the extreme triangle shapes. If measured in future, these multipole moments hold the potential of constraining β1. The results presented here are also important if one wishes to constrain fNL using redshift surveys.

scholarly journals Redshift space distortion of 21 cm line at 1 < $z$ < 5 with cosmological hydrodynamic simulations

2019 ◽  
Vol 484 (4) ◽  
pp. 5389-5399 ◽  
Author(s):  
Rika Ando ◽  
Atsushi J Nishizawa ◽  
Kenji Hasegawa ◽  
Ikkoh Shimizu ◽  
Kentaro Nagamine
Keyword(s):  
Hydrodynamic Simulations ◽  
Space Distortion

Old Futures

2018 ◽  
Author(s):  
Alexis Lothian
Keyword(s):  
Science Fiction ◽  
Digital Media ◽  
People Of Color ◽  
Narrative Form ◽  
Time Space ◽  
Race And Sexuality ◽  
History Of ◽  
Space Distortion ◽  
New Perspective ◽  
Feminist Utopias

Old Futures traverses the history of imagined futures from the 1890s to the 2010s, interweaving speculative visions of gender, race, and sexuality from literature, film, and digital media. Centering works by women, queers, and people of color that are marginalized within most accounts of the genre, the book offers a new perspective on speculative fiction studies while reframing established theories of queer temporality by arguing that futures imagined in the past offer new ways to queer the present. Imagined futures have been central to the creation and maintenance of imperial domination and technological modernity; Old Futures rewrites the history of the future by gathering together works that counter such narratives even as they are part of them. Lothian explores how queer possibilities are constructed and deconstructed through extrapolative projections and affective engagements with alternative temporalities. The book is structured in three parts, each addressing one convergence of political economy, theoretical framework, and narrative form that has given rise to a formation of speculative futurity. Six main chapters focus on white feminist utopias and dystopias of the nineteenth and twentieth centuries; on Afrofuturist narratives that turn the dehumanization of black lives into feminist and queer visions of transformation; on futuristic landscapes in queer speculative cinema; and on fan creators’ digital interventions into televised futures. Two shorter chapters, named “Wormholes” in homage to the science fiction trope of a time-space distortion that connects distant locations, highlight current resonances of the old futures under discussion.

scholarly journals Interpreting large-scale redshift-space distortion measurements

2012 ◽  
Vol 420 (3) ◽  
pp. 2102-2119 ◽  
Author(s):  
L. Samushia ◽  
W. J. Percival ◽  
A. Raccanelli
Keyword(s):  
Large Scale ◽  
Space Distortion
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