Search Publications
Probing the diffuse baryon distribution with the lensing-tSZ cross-correlation
Van Waerbeke, Ludovic; Hinshaw, Gary; Scott, Douglas +3 more
Approximately half of the Universe's baryons are in a form that has been hard to detect directly. However, the missing component can be traced through the cross-correlation of the thermal Sunyaev-Zeldovich (tSZ) effect with weak gravitational lensing. We build a model for this correlation and use it to constrain the extended baryon component, empl…
Constraints on cosmological parameters in power-law cosmology
Rani, Sarita; Altaibayeva, A.; Shahalam, M. +2 more
In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H0 (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with …
Non-local gravity and comparison with observational datasets
Kunz, Martin; Pettorino, Valeria; Dirian, Yves +2 more
We study the cosmological predictions of two recently proposed non-local modifications of General Relativity. Both models have the same number of parameters as ΛCDM, with a mass parameter m replacing the cosmological constant. We implement the cosmological perturbations of the non-local models into a modification of the CLASS Boltzmann code, and w…
Neutrinos in the holographic dark energy model: constraints from latest measurements of expansion history and growth of structure
Zhang, Jing-Fei; Zhang, Xin; Li, Yun-He +1 more
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter w ev…
Distinguishing interacting dark energy from wCDM with CMB, lensing, and baryon acoustic oscillation data
Väliviita, Jussi; Palmgren, Elina
We employ the Planck 2013 CMB temperature anisotropy and lensing data, and baryon acoustic oscillation (BAO) data to constrain a phenomenological wCDM model, where dark matter and dark energy interact. We assume time-dependent equation of state parameter for dark energy, and treat dark matter and dark energy as fluids whose energy-exchange rate is…
On the significance of power asymmetries in Planck CMB data at all scales
Notari, Alessio; Quartin, Miguel
We perform an analysis of the CMB temperature data taken by the Planck satellite investigating if there is any significant deviation from cosmological isotropy. We look for differences in the spectrum between two opposite hemispheres and also for dipolar modulations. We propose a new way to avoid biases due to partial-sky coverage by producing a m…
Cosmological constraints on deviations from Lorentz invariance in gravity and dark matter
Lesgourgues, J.; Audren, B.; Blas, D. +2 more
We consider a scenario where local Lorentz invariance is violated by the existence of a preferred time direction at every space-time point. This scenario can arise in the context of quantum gravity and its description at low energies contains a unit time-like vector field which parameterizes the preferred direction. The particle physics tests of L…
Polarized galactic synchrotron and dust emission and their correlation
Choi, Steve K.; Page, Lyman A.
We present an analysis of the level of polarized dust and synchrotron emission using the WMAP9 and Planck data. The primary goal of this study is to inform the assessment of foreground contamination in the cosmic microwave background (CMB) measurements below ℓ ~ 200 from 23 to 353 GHz. We compute angular power spectra as a function of sky cut base…
Distance priors from Planck 2015 data
Huang, Qing-Guo; Wang, Ke; Wang, Sai
We update the distance priors by adopting Planck TT,TE,EE+lowP data released in 2015, and our results impose at least 30% tighter constraints than those from Planck TT+lowP. Combining the distance priors with the combination of supernova Union 2.1 compilation of 580 SNe (Union 2.1) and low redshift Baryon Acoustic Oscillation (BAO) data, we constr…
Search for features in the spectrum of primordial perturbations using Planck and other datasets
Sarkar, Subir; Hunt, Paul
We reconstruct the power spectrum of primordial curvature perturbations by applying a well-validated non-parametric technique employing Tikhonov regularisation to the first data release from the Planck satellite. To improve the reconstruction on small spatial scales we include data from the ground-based ACT and SPT experiments, the WiggleZ galaxy …