304 research outputs found
Impact of cosmic neutrinos on the gravitational-wave background
No full textWe obtain the equation governing the evolution of the cosmological gravitational-wave background, accounting for the presence of cosmic neutrinos, up to second order in perturbation theory. In particular, we focus on the epoch during radiation dominance, after neutrino decoupling, when neutrinos yield a relevant contribution to the total energy density and behave as collisionless ultra-relativistic particles. Besides recovering the standard damping effect due to neutrinos, a new source term for gravitational waves is shown to arise from the neutrino anisotropic stress tensor. The importance of such a source term, so far completely disregarded in the literature, is related to the high velocity dispersion of neutrinos in the considered epoch; its computation requires solving the full second-order Boltzmann equation for collisionless neutrinos.We obtain the equation governing the evolution of the cosmological gravitational-wave background, accounting for the presence of cosmic neutrinos, up to second order in perturbation theory. In particular, we focus on the epoch during radiation dominance, after neutrino decoupling, when neutrinos yield a relevant contribution to the total energy density and behave as collisionless ultra-relativistic particles. Besides recovering the standard damping effect due to neutrinos, a new source term for gravitational waves is shown to arise from the neutrino anisotropic stress tensor. The importance of such a source term, so far completely disregarded in the literature, is related to the high velocity dispersion of neutrinos in the considered epoch/ its computation requires solving the full second-order Boltzmann equation for collisionless neutrinos
Isocurvature modes and Baryon Acoustic Oscillations II: Gains from combining CMB and Large Scale Structure
No full textWe consider cosmological parameters estimation in the presence of a non-zero isocurvature contribution in the primordial perturbations. A previous analysis showed that even a tiny amount of isocurvature perturbation, if not accounted for, could affect standard rulers calibration from Cosmic Microwave Background observations such as those provided by the Planck mission, affect Baryon Acoustic Oscillations interpretation, and introduce biases in the recovered dark energy properties that are larger than forecasted statistical errors from future surveys. Extending on this work, here we adopt a general fiducial cosmology which includes a varying dark energy equation of state parameter and curvature. Beside Baryon Acoustic Oscillations measurements, we include the information from the shape of the galaxy power spectrum and consider a joint analysis of a Planck-like Cosmic Microwave Background probe and a future, space-based, Large Scale Structure probe not too dissimilar from recently proposed surveys. We find that this allows one to break the degeneracies that affect the Cosmic Microwave Background and Baryon Acoustic Oscillations combination. As a result, most of the cosmological parameter systematic biases arising from an incorrect assumption on the isocurvature fraction parameter fiso, become negligible with respect to the statistical errors. We find that the Cosmic Microwave Background and Large Scale Structure combination gives a statistical error σ(fiso) ∼ 0.008, even when curvature and a varying dark energy equation of state are included, which is smaller that the error obtained from Cosmic Microwave Background alone when flatness and cosmological constant are assumed. These results confirm the synergy and complementarity between Cosmic Microwave Background and Large Scale Structure, and the great potential of future and planned galaxy surveys
Toxic Landscapes
No full textToxic Landscapes addresses the regenerative remediation of the former Ceramiche Girardi orphan site in Palazzolo dello Stella, abandoned in 2008. The research explores how a project can restore contaminated landscapes and redefine the identity of a place. The first analyzes PNRR Investment 3.4 for the remediation of orphan sites. The second part examines international reclamation projects, highlighting effective strategies. The third part focuses on the former Ceramiche Girardi, analyzing the degradation of the area and the potential for transformation through environmental engineering and architecture for the landscape
Alle origini del tipo del togato in Cisalpina: le statue di Palazzo Mangilli a Udine
No full textIn the collection of antiquities of Palazzo Mangilli in Udine (Northern Italy) there are three unpublished togate statues in limestone, dating back to the late Republican age. The togatus "A" is closely compared to a group of statues produced in Rome in the first half of the first century. B.C. The statue "B", very similar to the previous one in the rendering of the drapery and in various details, is linked to the tradition of the figures with himation of the Hellenistic world. The statues are product of a same atelier, designed for the same context, most likely a large funerary monument of Aquileia dated in the second quarter of the I century BC: most likely they are the oldest togate statues of the Cisalpine Gaul. Also the statuary type of "C" is that of the togatus with arm sling, and is datable in the third quarter of the first century BC. The heads, in marble, do not belong to the statues, and date back to the Imperial age
Book review: The Fascist Party and popular opinion inMussolini’s Italy
No full textIn The Fascist Party and Popular Opinion in Mussolini’s Italy, Paul Corner reexamines the experience of Italy during Mussolini’s fascist regime. Based largely on unpublished archival material, the book concludes by suggesting that the abuse of power by fascists mirrors much wider problems in Italy related to the relationship between the public and the private and to the modes of utilisation of power, both in the past and in the present. Massimo Mangilli-Climpson finds the book contains a well-argued discussion raising a number of new points about the country’s development in the early 20th century
Octreotide in the management of intestinal obstruction in terminal cancer patients.
No full textOctreotide in the management of intestinal obstruction in terminal cancer patients
Optimal bispectrum estimator and simulations of the CMB lensing-integrated Sachs Wolfe non-Gaussian signal
No full textWe present the tools to optimally extract the lensing-integrated Sachs Wolfe (L-ISW) bispectrum signal from future cosmic microwave background (CMB) data. We implemented two different methods to simulate the non-Gaussian CMB maps with the L-ISW signal: a non-perturbative method based on the FLINTS lensing code and the separable mode-expansion method. We implemented the Komatsu, Spergel, and Wandelt (KSW) optimal estimator analysis for the L-ISW bispectrum and tested it on the non-Gaussian simulations for realistic CMB experimental settings with an inhomogeneous sky coverage. We show that the estimator approaches the Cramer-Rao bound and that Wiener filtering the L-ISW simulations slightly improves the estimate of fNLL-ISW by ≤ 10%. For a realistic CMB experimental setting that accounts for anisotropic noise and masked sky, we show that the linear term of the estimator is highly correlated to the cubic term and it is necessary to recover the signal and the optimal error bars. We also show that the L-ISW bispectrum, if not correctly accounted for, yields an underestimation of the fNLlocal error bars of ≃ 4%. A joint analysis of the non-Gaussian shapes and/or L-ISW template subtraction is needed to recover unbiased results of the primordial non-Gaussian signal from ongoing and future CMB experiments
The CMB at large angular scale: status of the constraints on reionization
No full textInternational audienc
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