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相关论文: Fundamental limits on constraining primordial non-…

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We study the extent to which one can distinguish primordial non--Gaussianity (NG) arising from adiabatic and isocurvature perturbations. We make a joint analysis of different NG models based on various inflationary scenarios: local-type and…

宇宙学与河外天体物理 · 物理学 2010-05-12 Chiaki Hikage , Dipak Munshi , Alan Heavens , Peter Coles

The cosmic microwave background (CMB) lensing power spectrum is a powerful probe of the late-time universe, encoding valuable information about cosmological parameters such as the sum of neutrino masses and dark energy equation of state.…

宇宙学与河外天体物理 · 物理学 2024-10-11 Hongbo Cai , Yilun Guan , Toshiya Namikawa , Arthur Kosowsky

It was pointed out recently that in some inflationary models quantum loops containing a scalar of mass $m$ that couples to the inflaton can be the dominant source of primordial non-Gaussianities. We explore this phenomenon in the simplest…

高能物理 - 唯象学 · 物理学 2019-03-27 Haipeng An , Mark B. Wise , Zipei Zhang

The power spectrum of weak lensing fluctuations has a non-Gaussian distribution due to its quadratic nature. On small scales the Central Limit Theorem acts to Gaussianize this distribution but non-Gaussianity in the signal due to…

宇宙学与河外天体物理 · 物理学 2022-06-29 Alex Hall , Andy Taylor

We quantify the Fisher information content of the cosmic shear survey two-point function as a function of noise and resolution. The two point information of dark matter saturates at the trans-linear scale. We investigate the impact of…

宇宙学与河外天体物理 · 物理学 2009-05-06 Olivier Doré , Tingting Lu , Ue-Li Pen

Forecasts and analyses of cosmological observations often rely on the assumption of a perfect theoretical model over a defined range of scales. We explore how model uncertainties and nuisance parameters in perturbative models of the matter…

宇宙学与河外天体物理 · 物理学 2016-02-02 Tobias Baldauf , Mehrdad Mirbabayi , Marko Simonović , Matias Zaldarriaga

We study inviscid limits of invariant measures for the 2D Stochastic Navier-Stokes equations. As shown in \cite{Kuksin2004} the noise scaling $\sqrt{{\nu}}$ is the only one which leads to non-trivial limiting measures, which are invariant…

偏微分方程分析 · 数学 2013-02-05 Nathan Glatt-Holtz , Vladimir Sverak , Vlad Vicol

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. At low redshifts, the non-linear gravitational evolution of large scale structure produces a…

天体物理学 · 物理学 2009-10-31 Asantha Cooray , Wayne Hu

We study how well perturbative forward modeling can constrain cosmological parameters compared to conventional analyses. We exploit the fact that in perturbation theory the field-level posterior can be computed analytically in the limit of…

宇宙学与河外天体物理 · 物理学 2024-01-31 Giovanni Cabass , Marko Simonović , Matias Zaldarriaga

The squeezed limit of the primordial curvature bispectrum is an extremely sensitive probe of new physics and encodes information about additional fields active during inflation such as their masses and spins. In the conventional setup,…

高能物理 - 理论 · 物理学 2024-01-23 Ciaran McCulloch , Enrico Pajer , Xi Tong

Large-scale Fourier modes of the cosmic density field are of great value for learning about cosmology because of their well-understood relationship to fluctuations in the early universe. However, cosmic variance generally limits the…

宇宙学与河外天体物理 · 物理学 2022-01-05 Omar Darwish , Simon Foreman , Muntazir M. Abidi , Tobias Baldauf , Blake D. Sherwin , P. Daniel Meerburg

We study the large-scale bias parameter of cosmic voids with primordial non-Gaussian (PNG) initial conditions of the local type. In this scenario, the dark matter halo bias exhibits a characteristic scale dependence on large scales, which…

宇宙学与河外天体物理 · 物理学 2019-07-03 Kwan Chuen Chan , Nico Hamaus , Matteo Biagetti

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

宇宙学与河外天体物理 · 物理学 2026-04-09 Veronika Oehl , Tilman Tröster

The primordial non-Gaussianity induces scale-dependent bias of the \hi with respect to the underlying dark matter, which exhibits features on the very large scales of the 21-cm power spectrum potentially observable with \hi intensity…

宇宙学与河外天体物理 · 物理学 2017-10-04 Yi-Chao Li , Yin-Zhe Ma

Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular it may help tighten constraints on parameters describing the…

宇宙学与河外天体物理 · 物理学 2017-09-14 Philipp M. Merkel , Bjoern Malte Schaefer

Recent results of N-body simulations have shown that current theoretical models are not able to correctly predict the amplitude of the scale-dependent halo bias induced by primordial non-Gaussianity, for models going beyond the simplest,…

宇宙学与河外天体物理 · 物理学 2013-05-29 Vincent Desjacques , Donghui Jeong , Fabian Schmidt

Measuring the three-point correlators of the Cosmic Microwave Background (CMB) anisotropies could help to get a handle on the level of non-Gaussianity present in the observational datasets and therefore would strongly constrain models of…

天体物理学 · 物理学 2008-11-26 Alejandro Gangui , Jerome Martin

We study the effect of primordial isocurvature perturbations on non-Gaussian properties of CMB temperature anisotropies. We consider generic forms of the non-linearity of isocurvature perturbations which can be applied to a wide range of…

天体物理学 · 物理学 2009-09-30 Chiaki Hikage , Kazuya Koyama , Takahiko Matsubara , Tomo Takahashi , Masahide Yamaguchi

Making cosmological inferences from the observed galaxy clustering requires accurate predictions for the mean clustering statistics and their covariances. Those are affected by cosmic variance -- the statistical noise due to the finite…

宇宙学与河外天体物理 · 物理学 2020-04-08 Anatoly Klypin , Francisco Prada , Joyce Byun

Diffusion damping of the cosmic microwave background (CMB) power spectrum results from imperfect photon-baryon coupling in the pre-recombination plasma. At redshift $5 \times 10^4 < z < 2 \times 10^6$, the plasma acquires an effective…