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相关论文: COBE-DMR constraints on the nonlinear coupling par…

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We calculate the large-angle cross-correlation between the cosmic-microwave-background (CMB) temperature and the x-ray-background (XRB) intensity expected in an open Universe with cold dark matter (CDM) and a nearly scale-invariant spectrum…

天体物理学 · 物理学 2009-10-30 Ali Kinkhabwala , Marc Kamionkowski

Gauss--Bonnet inflation typically affects the dynamics over an extended portion of the trajectory, making it difficult to isolate a controlled imprint at CMB scales. We consider a trajectory-selective coupling \(\mu(\phi,X)\) that gates the…

宇宙学与河外天体物理 · 物理学 2026-05-08 Ali Seidabadi , Sara Saghafi , Kourosh Nozari

The Davenport spectrum is a modification of the classical Kolmogorov spectrum for the inertial range of turbulence that accounts for non-scaling low frequency behavior. Like the classical fractional Brownian motion vis-\`a-vis the…

统计理论 · 数学 2018-08-16 B. Cooper Boniece , Gustavo Didier , Farzad Sabzikar

We present forecasts on the primordial non-Gaussianity parameter $f_\text{NL}$ of feature models for the future Cosmic Microwave Background Stage-4 (CMB-S4) experiments. The Fisher matrix of the bispectrum estimator was computed using noise…

宇宙学与河外天体物理 · 物理学 2019-10-02 Wuhyun Sohn , James Fergusson

Recently, it has been shown that cross-correlating CMB lensing and 3D cosmic shear allows to considerably tighten cosmological parameter constraints. We investigate whether similar improvement can be achieved in a conventional tomographic…

宇宙学与河外天体物理 · 物理学 2017-07-27 Philipp M. Merkel , Bjoern Malte Schaefer

Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only…

宇宙学与河外天体物理 · 物理学 2019-09-04 Chan-Gyung Park , Bharat Ratra

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

天体物理学 · 物理学 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

We use the two-point correlation function of the extrema points (peaks and valleys) in the COBE Differential Microwave Radiometers (DMR) 2-year sky maps as a test for non-Gaussian temperature distribution in the cosmic microwave background…

天体物理学 · 物理学 2011-05-10 A. Kogut , A. J. Banday , C. L. Bennett , G. Hinshaw , P. M. Lubin , G. F. Smoot

Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the…

天体物理学 · 物理学 2007-05-23 Dipak Munshi , Patrick Valageas

In the context of inflationary scenarios, the observed large angle anisotropy of the Cosmic Microwave Background (CMB) temperature is believed to probe the primordial metric perturbations from inflation. Although the perturbations from…

天体物理学 · 物理学 2019-08-17 Somnath Bharadwaj , Dipak Munshi , Tarun Souradeep

It has been shown that primordial tensor non-Gaussianities from a cubic Weyl action with a non-dynamical coupling are suppressed by the so-called slow-roll parameter in a conventional framework of slow-roll inflation. In this paper, we…

广义相对论与量子宇宙学 · 物理学 2024-09-18 Shingo Akama , Mian Zhu

As recently shown by Viola et al., the common (KSB) method for measuring weak gravitational shear creates a non-linear relation between the measured and the true shear of objects. We investigate here what effect such a non-linear…

宇宙学与河外天体物理 · 物理学 2015-05-27 Matthias Bartelmann , Massimo Viola , Peter Melchior , Björn M. Schäfer

We study the perspectives to extract information about the microphysical parameters that governed the reheating process after cosmic inflation from CMB data. We identify conditions under which the inflaton coupling to other fields can be…

宇宙学与河外天体物理 · 物理学 2022-09-30 Marco Drewes

We consider a cosmological model with non-Gaussian initial perturbations, which in principle could be generated in non-standard inflationary scenarios with two or more scalar fields. In particular we focus our attention on the model…

天体物理学 · 物理学 2011-05-10 Dmitri Novikov , Jens Schmalzing , Viatcheslav F. Mukhanov

Recent analysis of the combined data of cosmic microwave background, galaxy clustering and supernovae type Ia observations have set strong constraints on the equation of state parameter $w_X$. The upper bound $w_X < -0.82$ at 95% c.l. rules…

天体物理学 · 物理学 2008-11-26 Luca Conversi , Alessandro Melchiorri , Laura Mersini , Joseph Silk

We present updated observational constraints on the spatially flat $\phi$CDM model, where dark energy is described by a minimally coupled scalar field $\phi$ with an inverse power-law potential $V=V_0 \phi^{-\alpha}$. Using Planck 2018 CMB…

宇宙学与河外天体物理 · 物理学 2025-10-01 Chan-Gyung Park , Bharat Ratra

Polarization of the cosmic microwave background (CMB) can help probe cosmic inflation (via primordial $B$ modes) and test parity-violating physics (via cosmic birefringence), but realizing the potential of these opportunities requires…

宇宙学与河外天体物理 · 物理学 2024-05-17 Marta Monelli

By considering simple, but representative, models of brane inflation from a single brane-antibrane pair in the slow roll regime, we provide constraints on the parameters of the theory imposed by measurements of the CMB anisotropies by WMAP…

天体物理学 · 物理学 2008-11-26 Richard A. Battye , Bjorn Garbrecht , Adam Moss , Horace Stoica

We study constraints on the natural inflation model from the cosmic microwave background radiation (CMBR). Inflaton \phi for the natural inflation has a potential of the form V=\Lambda^4[1-\cos(\phi/\sqrt{2}f_\phi)], which is parametrized…

高能物理 - 唯象学 · 物理学 2009-10-31 Takeo Moroi , Tomo Takahashi

We report forecast constraints on warm inflation in the light of future cosmic microwave background (CMB) surveys, with data expected to be available in the coming decade. These observations could finally give us the missing information…

宇宙学与河外天体物理 · 物理学 2025-04-04 F. B. M. dos Santos , G. Rodrigues , R. de Souza , J. S. Alcaniz