Search Publications
Measuring the thermal Sunyaev-Zel'dovich effect through the cross correlation of Planck and WMAP maps with ROSAT galaxy cluster catalogs
Battaglia, Nicholas; Bond, J. Richard; Spergel, David N. +3 more
We measure a significant correlation between the thermal Sunyaev-Zel'dovich effect in the Planck and WMAP maps and an X-ray cluster map based on ROSAT. We use the 100, 143 and 343 GHz Planck maps and the WMAP 94 GHz map to obtain this cluster cross spectrum. We check our measurements for contamination from dusty galaxies using the cross correlatio…
Testing the dipole modulation model in CMBR
Jain, Pankaj; Rath, Pranati K.
The hemispherical power asymmetry, observed in the CMBR data, has generally been interpreted in terms of the dipole modulation model for the temperature fluctuations. Here we point out that this model leads to several predictions, which can be directly tested in the current data. We suggest tests of the hemispherical power asymmetry both in real a…
Warming up for Planck
Rosa, João G.; Bartrum, Sam; Berera, Arjun
The recent Planck results and future releases on the horizon present a key opportunity to address a fundamental question in inflationary cosmology of whether primordial density perturbations have a quantum or thermal origin, i.e. whether particle production may have significant effects during inflation. Warm inflation provides a natural arena to a…
Single-field inflation à la generalized Chaplygin gas
del Campo, Sergio
In the simplest scenario for inflation, i.e. in the single-field inflation, it is presented an inflaton field with properties equivalent to a generalized Chaplygin gas. Their study is performed using the Hamilton-Jacobi approach to cosmology. The main results are contrasted with the measurements recently released by the Planck data, combined with …
Large-scale anomalies of the CMB in the curvaton scenario
Liu, Hao; Naselsky, Pavel; Frejsel, Anne Mette
We extend the curvaton scenario presented by Erickcek et al. [1,2], to explain how the even-odd multipole asymmetry of the Cosmic Microwave Background (CMB) (also called parity asymmetry, [3,4]) and power anisotropies can be generated by the curvaton field, which acts as an extra component to the spectrum of adiabatic perturbations in the inflatio…
Orbifold line topology and the cosmic microwave background
Rathaus, Ben; Ben-David, Assaf; Itzhaki, Nissan
We extend our study of a universe with a non-classical stringy topology, and consider an orbifold line topology, Bbb R × Bbb R2/Bbb Zp. This topology has a fixed line and identifies each point in space with p-1 other points. An observable imprint of an orbifold line on the CMB is the appearance of up to (p-1)/2 pairs of match…
Consistency tests for Planck and WMAP in the low multipole domain
Frejsel, A.; Liu, H.; Hansen, M.
Recently, full sky maps from Planck have been made publicly available. In this paper, we do consistency tests for the three Planck CMB sky maps. We assume that the difference between two maps represents the contributions from systematics, noise, foregrounds and other sources, and that a precise representation of the Cosmic Microwave Background sho…
Inflation in the generalized inverse power law scenario
Lu, Zhun
We propose a single field inflationary model by generalizing the inverse power law potential from the intermediate model. We study the implication of our model on the primordial anisotropy of cosmological microwave background radiation. Specifically, we apply the slow-roll approximation to calculate the scalar spectral tilt ns and the t…
Constraints on cosmological models from strong gravitational lensing systems
Cao, Shuo; Biesiada, Marek; Zhu, Zong-Hong +2 more
Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two an…
Unidentified sources in the Fermi-LAT second source catalog: the case for DM subhalos
Horns, Dieter; Zechlin, Hannes-S.
The Large Area Telescope (LAT) aboard the Fermi satellite allows us to study the high-energy γ-ray sky with unprecedented sensitivity. However, the origin of 31% of the detected γ-ray sources remains unknown. This population of unassociated γ-ray sources may contain new object classes, among them sources of photons from self-annihilating or decayi…