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According to the most popular scenario, the early Universe should have experienced an accelerated expansion phase, called Cosmological Inflation, after which the standard Big Bang Cosmology would have taken place giving rise to the radiation-dominated epoch. However, the details of the inflationary scenario are far to be completely understood. Thus, in this paper we study if possible additional (exotic) cosmological phases could delay the beginning of the standard Big Bang history and alter some theoretical predictions related to the inflationary cosmological perturbations, like, for instance, the order of magnitude of the tensor-to-scalar ratio r.A post-publication change was made to this article on 4 Jun 2020 to correct the title on the webpage.

The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K cosmic microwave background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the Universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole l peak = (197 ± 6), with an amplitude Δ T 200 = (69 ± 8) µK. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favoured by standard inflationary models.

A first measurement of Cosmic Microwave Background B-mode polarization on large scales could provide a convincing confirmation of the existence of a primordial background of gravitational waves as predicted in the inflation scenario. A major obstacle to observe B-modes is represented by polarized foreground contamination from our Galaxy. In particular, thermal dust and synchrotron emission dominate over the primordial signal at high and low frequencies, respectively. Several experiments have been designed to observe B-mode polarization. Here, we focus on the forthcoming LSPE-SWIPE balloon experiment, devoted to the accurate observation of large scale CMB polarization, and present preliminary forecasts on the impact of foreground contamination on LSPE-SWIPE observations. Using the last release of Planck foreground maps as templates, we estimate the amplitude of dust and synchrotron emission in the sky region and at the frequency channels of interest for LSPE-SWIPE. Furthermore, we investigate the generation of polarization-optimized Galactic masks and we give preliminary indications on the requirements of component separation methods.

The search for the B-mode polarization of Cosmic Microwave Background (CMB) is the new frontier of observational Cosmology. A B-mode detection would give an ultimate confirmation to the existence of a primordial Gravitational Wave (GW) background as predicted in the inflationary scenario. Several experiments have been designed or planned to observe B-modes. In this work we focus on the forthcoming Large Scale Polarization Explorer (LSPE) experiment, that will be devoted to the accurate measurement of CMB polarization at large angular scales. LSPE consists of a balloon-borne bolometric instrument, the Short Wavelength Instrument for the Polarization Explorer (SWIPE), and a ground-based coherent polarimeter array, the STRatospheric Italian Polarimeter (STRIP). SWIPE will employ a rotating Half Wave Plate (HWP) polarization modulator to mitigate the systematic effects due to instrumental non-idealities. We present here preliminary forecasts aimed at optimizing the HWP configuration.

In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross- correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales.

In this work we describe a possible way to use X-ray and microwave observations of nearby galaxy clusters to derive the value of the Hubble constant, that parametrises the expansion rate of the Universe. We provide a brief introduction to the Sunyaev-Zel'dovich effect that allows to detect galaxy clusters at microwave frequencies, and the method to combine it with X-ray observables. We emphasize what kind of considerations should be done when applying the method on real data and study the effect of the geometry of the clusters on the final result.

Hi-GAL, the Herschel infrared Galactic Plane Survey, is an Open Time Key Project of theHerschel Space Observatory. It will make an unbiased photometric survey of the inner Galactic plane by mapping a2° 2 ° wide strip in the longitude range∣l∣ < 60° ∣ l ∣ < 60 ° in five wavebands between 70 μm and 500 μm. The aim of Hi-GAL is to detect the earliest phases of the formation of molecular clouds and high-mass stars and to use the optimum combination ofHerschelwavelength coverage, sensitivity, mapping strategy, and speed to deliver a homogeneous census of star-forming regions and cold structures in the interstellar medium. The resulting representative samples will yield the variation of source temperature, luminosity, mass and age in a wide range of Galactic environments at all scales from massive YSOs in protoclusters to entire spiral arms, providing an evolutionary sequence for the formation of intermediate and high-mass stars. This information is essential to the formulation of a predictive global model of the role of environment and feedback in regulating the star-formation process. Such a model is vital to understanding star formation on galactic scales and in the early universe. Hi-GAL will also provide a science legacy for decades to come with incalculable potential for systematic and serendipitous science in a wide range of astronomical fields, enabling the optimum use of future major facilities such asJWSTand ALMA.

One of the goals of Space Weather studies is to achieve a better understanding of impulsive phenomena, such as Coronal Mass Ejections (CMEs), in order to improve our ability to forecast them and mitigate the risk to our technologically driven society. The essential part of achieving this goal is to assess the performance of forecasting models. To this end, the quality and availability of suitable data are of paramount importance. In this work, we have merged already publicly available data of CMEs from both in-situ and remote instrumentation in order to build a database of CME properties. To evaluate the accuracy of such a database and confirm the relationship between in-situ and remote observations, we have employed the drag-based model (DBM) due to its simplicity and inexpensive cost of computational resources. In this study, we have also explored the parameter space for the drag parameter and solar wind speed using a Monte Carlo approach to evaluate how well the DBM determines the propagation of CMEs for the events in the dataset. The dataset of geoeffective CMEs constructed as a result of this work provides validation of the initial hypothesis about DBM, and solar wind speed and also yields further insight into CME features like arrival time, arrival speed, lift-off time, etc. Using a data-driven approach, this procedure allows us to present a homogeneous, reliable, and robust dataset for the investigation of CME propagation. On the other hand, possible CME events are identified where DBM approximation is not valid due to model limitations and higher uncertainties in the input parameters, those events require more thorough investigation.

We describe a microfluidic device for separating cells according to their dielectric properties by combining 2-dimensional dielectrophoretic forces with field-flow-fractionation. The device comprises a thin chamber in which a travelling-wave electrical field is generated by a planar, multilayer microelectrode array at the bottom. Under the balance of gravitational and dielectrophoretic levitation forces, cells introduced into the device are positioned at different equilibrium heights in a velocity profile established inside the chamber, and thereby transported at different velocities by the fluid. Simultaneously, cells are subjected to a horizontal travelling-wave dielectrophoretic force that deflects them across the flow stream. The 2-dimensional dielectrophoretic forces acting on cells and the associated velocities in the fluid-flow and travelling-field directions depend sensitively on cell dielectric properties. The responses of cultured MDA-435 human breast cancer, HL-60 human leukemia and DS19 murine erythroleukemia cells, and of peripheral blood mononuclear (PBMN) cells were studied as functions of the frequency and voltage of the applied electric signals, and of the fluid flow rate. Significant differences were observed between the responses of different cell types. Cell separation was demonstrated by the differential redistribution of MDA-435 and PBMN cells as they flowed through the device. The device can be readily integrated with other microfluidic components for microscale sample preparation and analysis.

The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (PILOT) is a balloon-borne experiment that aims to measure the polarized emission of thermal dust at a wavelength of 240 um (1.2 THz). The PILOT experiment flew from Timmins, Ontario, Canada in 2015 and 2019 and from Alice Springs, Australia in April 2017. The in-flight performance of the instrument during the second flight was described in Mangilli et al. 2019. In this paper, we present data processing steps that were not presented in Mangilli et al. 2019 and that we have recently implemented to correct for several remaining instrumental effects. The additional data processing concerns corrections related to detector cross-talk and readout circuit memory effects, and leakage from total intensity to polarization. We illustrate the above effects and the performance of our corrections using data obtained during the third flight of PILOT, but the methods used to assess the impact of these effects on the final science-ready data, and our strategies for correcting them will be applied to all PILOT data. We show that the above corrections, and in particular that for the intensity to polarization leakage, which is most critical for accurate polarization measurements with PILOT, are accurate to better than 0.4 % as measured on Jupiter during flight#3.