194 results on '"Bonometto, S. A."'
Search Results
152. Conditions for galaxy formation from adiabatic fluctuations
- Author
-
Bonometto, S. A., primary and Lucchin, F., additional
- Published
- 1976
- Full Text
- View/download PDF
153. Physical processes in the universe at the epoch of the quark-hadron transition
- Author
-
Bonometto, S. A., primary and Sakellariadou, M., additional
- Published
- 1984
- Full Text
- View/download PDF
154. On Possible Observable Effects of Electron Pair Production in QSOs
- Author
-
Bonometto, S., primary and Rees, M. J., additional
- Published
- 1971
- Full Text
- View/download PDF
155. BaR-SPOrt: Balloon-Borne Radiometers for Sky Polarization Observations.
- Author
-
Shaver, Peter A., DiLella, Luigi, Giménez, Alvaro, Sbarra, C., Cortiglioni, S., Bernardi, G., Carretti, E., Cecchini, S., Macculi, C., Ventura, G., Baralis, M., Peverini, O., Tascone, R., Boella, G., Bonometto, S., Gervasi, M., Sironi, G., Tucci, M., Zannoni, M., and Natale, V.
- Abstract
BaR-SPOrt, funded by ASI (Italian Space Agency), is a 32 (90) GHz balloon-borne correlation polarimeter for direct measurements of the Q and U Stokes parameters, with an angular resolution of $0.6^{\circ} (0.2^{\circ}$). Aim of the experiment is the detection of the polarized emission of the diffuse Galactic Background and the Cosmic Microwave Background (CMB). The most likely launch site is Antarctica (2 to 4-week flight). Kiruna (Sweden, 1-week flight) and Svalbard (Norway, > 1-week flight) are possible launch site to observe the Northern sky. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
156. The Sky Polarization Observatory (SPOrt) Programme.
- Author
-
Shaver, Peter A., DiLella, Luigi, Giménez, Alvaro, Carretti, E., Cortiglioni, S., Bernardi, G., Cecchini, S., Macculi, C., Sbarra, C., Monari, J., Orfei, A., Poppi, S., Boella, G., Bonometto, S., Gervasi, M., Sironi, G., Zannoni, M., Tucci, M., Baralis, M., and Peverini, O. A.
- Abstract
SPOrt is an experiment aimed at making a polarization survey of the sky in the microwave range (22-90 GHz) on large angular scales (FWHM = $7^{\circ}$). [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
157. Extending the Coyote emulator to dark energy models with standard w0-wa parametrization of the equation of state.
- Author
-
Casarini, L., Bonometto, S. A., Tessarotto, E., and Corasaniti, P. -S
- Published
- 2016
- Full Text
- View/download PDF
158. Do WMAP data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?
- Author
-
Vacca, G. La, Kristiansen, J. R., Colombo, L. P. L., Mainini, R., and Bonometto, S. A.
- Published
- 2009
- Full Text
- View/download PDF
159. Physics of the Cosmological Quark-Hadron Transition
- Author
-
Bonometto, S. A. and Pantano, O.
- Published
- 1993
- Full Text
- View/download PDF
160. The cosmological quark-hadron transition
- Author
-
Bonometto, S
- Published
- 1991
- Full Text
- View/download PDF
161. Biased theories of galaxy formation with arbitrary threshold functions and background distribution
- Author
-
Bonometto, S [Scuola Internazionale Superiore di Studi Avanzati, Trieste (Italy) Perugia Universita (Italy)]
- Published
- 1990
- Full Text
- View/download PDF
162. Higher neutrino mass allowed if Cold Dark Matter and Dark Energy are coupled
- Author
-
S. Bonometto, G. La Vacca, L. P. L. Colombo, LA VACCA, G, Bonometto, S, and Colombo, L
- Subjects
Physics ,Particle physics ,Astrophysics::High Energy Astrophysical Phenomena ,Hot dark matter ,Astrophysics (astro-ph) ,Scalar field dark matter ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astronomy and Astrophysic ,Astrophysics ,Thermodynamics of the universe ,Space and Planetary Science ,Neutrino ,Mixed dark matter ,Warm dark matter ,High Energy Physics::Experiment ,Cosmology: theory ,Instrumentation ,Light dark matter ,Dark fluid - Abstract
Cosmological limits on neutrino masses are softened, by more than a factor 2, if Cold Dark Matter (CDM) and Dark Energy (DE) are coupled. In turn, a neutrino mass yielding $\Omega_\nu$ up to $\sim0.20$ allows coupling levels $\beta \simeq 0.15, $ or more, already easing the coincidence problem. The coupling, in fact, displaces both $P(k)$ and $C_l$ spectra in a fashion opposite to neutrino mass. Estimates are obtained through a Fisher--matrix technique., Comment: 22 pages, 9 figures. Added appendix and references, corrected typos. Version to appear in New Astronomy
- Published
- 2009
163. Strongly Coupled Dark Energy Cosmologies: preserving LCDM success and easing low scale problems I - Linear theory revisited
- Author
-
R. Mainini, Andrea V. Macciò, Silvio A. Bonometto, Bonometto, S, Mainini, R, and Macciò, A
- Subjects
Physics ,Fine-tuning ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Cosmic microwave background ,Dark matter ,Galaxies: evolution ,Large-scale structure of universe ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Galaxies: formation ,Coupling (probability) ,Cosmology ,Theoretical physics ,Space and Planetary Science ,Dark energy ,Field theory (psychology) ,Darkmatter ,Scalar field ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
In this first paper we discuss the linear theory and the background evolution of a new class of models we dub SCDEW: Strongly Coupled DE, plus WDM. In these models, WDM dominates today's matter density; like baryons, WDM is uncoupled. Dark Energy is a scalar field $\Phi$; its coupling to ancillary CDM, whose today's density is $\ll 1\, \%$, is an essential model feature. Such coupling, in fact, allows the formation of cosmic structures, in spite of very low WDM particle masses ($\sim 100$ eV). SCDEW models yields Cosmic Microwave Background and linear Large Scale features substantially undistinguishable from $\Lambda$CDM, but thanks to the very low WDM masses they strongly alleviate $\Lambda$CDM issues on small scales, as confirmed via numerical simulations in the II associated paper. Moreover SCDEW cosmologies significantly ease the coincidence and fine tuning problems of $\Lambda$CDM and, by using a field theory approach, we also outline possible links with inflationary models. We also discuss a possible fading of the coupling at low redshifts which prevents non linearities on the CDM component to cause computational problems. The (possible) low-$z$ coupling suppression, its mechanism, and its consequences are however still open questions -not necessarily problems- for SCDEW models. The coupling intensity and the WDM particle mass, although being extra parameters in respect to $\Lambda$CDM, are found to be substantially constrained a priori so that, if SCDEW is the underlying cosmology, we expect most data to fit also $\Lambda$CDM predictions., Comment: 11 pages, 9 figures , accepted for publication on MNRAS; updated to match the published version; the companion paper can be found here http://arxiv.org/abs/1503.07867
- Published
- 2015
164. Strongly Coupled Dark Energy Cosmologies: preserving LCDM success and easing low scale problems II - Cosmological simulations
- Author
-
R. Mainini, Camilla Penzo, Silvio A. Bonometto, Andrea V. Macciò, Macciò, A, Mainini, R, Penzo, C, and Bonometto, S
- Subjects
Physics ,Cold dark matter ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Hot dark matter ,Scalar field dark matter ,Galaxies: evolution ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Dark matter halo ,Space and Planetary Science ,Cuspy halo problem ,Warm dark matter ,Cosmology: dark matter ,Light dark matter ,Astrophysics::Galaxy Astrophysics ,Dark fluid ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
In this second paper we present the first Nbody cosmological simulations of strongly coupled Dark Energy models (SCDEW), a class of models that alleviates theoretical issues related to the nature of dark energy. SCDEW models assume a strong coupling between Dark Energy (DE) and an ancillary Cold Dark Matter (CDM) component together with the presence of an uncoupled Warm Dark Matter component. The strong coupling between CDM and DE allows us to preserve small scale fluctuations even if the warm particle is quite light ($\approx 100$ eV). Our large scale simulations show that, for $10^{11}, Comment: 9 pages, 10 figures, MNRAS accepted, the companion paper can be found at http://arxiv.org/abs/1503.07875
- Published
- 2015
- Full Text
- View/download PDF
165. Strongly Coupled Cosmologies
- Author
-
R. Mainini, S. A. Bonometto, Marino Mezzetti, I. Musco, Andrea V. Macciò, Bonometto, S, Mezzetti, M, Musco, I, Mainini, R, and Maccio', A
- Subjects
Physics ,Nuclear and High Energy Physics ,Sterile neutrino ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,Cosmic microwave background ,Linear system ,FOS: Physical sciences ,Scale (descriptive set theory) ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,7. Clean energy ,Spectral line ,General Relativity and Quantum Cosmology ,Coupling (physics) ,13. Climate action ,0103 physical sciences ,Radiative transfer ,Gravitino ,Astrophysics , Cosmology and Nongalactic Astrophysics ,010303 astronomy & astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Models including an energy transfer from CDM to DE are widely considered in the literature, namely to allow DE a significant high-z density. Strongly Coupled cosmologies assume a much larger coupling between DE and CDM, together with the presence of an uncoupled warm DM component, as the role of CDM is mostly restricted to radiative eras. This allows us to preserve small scale fluctuations even if the warm particle, possibly a sterile neutrino, is quite light, O(100 eV). Linear theory and numerical simulations show that these cosmologies agree with LCDM on supergalactic scales; e.g., CMB spectra are substantially identical. Simultaneously, simulations show that they significantly ease problems related to the properties of MW satellites and cores in dwarfs. SC cosmologies also open new perspectives on early black hole formation, and possibly lead towards unificating DE and inflationary scalar fields., Comment: 4 pages, 6 figures, Proceeding of the "Neutrino Oscillation Workshop" NOW 2014, Conca Specchiulla, Otranto, Italy, 7-14 September 2014
- Published
- 2014
166. Fluctuations in strongly coupled cosmologies
- Author
-
Silvio A. Bonometto, Roberto Mainini, Bonometto, S, and Mainini, R
- Subjects
Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,dark matter theory ,Horizon ,media_common.quotation_subject ,Cosmic microwave background ,FOS: Physical sciences ,cosmological parameters from CMBR ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Coupling (probability) ,Omega ,Universe ,Attractor ,dark energy theory ,Scalar field ,Energy (signal processing) ,Mathematical physics ,media_common ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
In the early Universe, a dual component made of coupled CDM and a scalar field $\Phi$, if their coupling $\beta > \sqrt{3}/2$, owns an attractor solution, making them a stationary fraction of cosmic energy during the radiation dominated era. Along the attractor, both such components expand $\propto a^{-4}$ and have early density parameters $\Omega_{d} = 1/ (4\beta^2)$ and $\Omega_c= 2, \Omega_d$ (field and CDM, respectively). In a previous paper it was shown that, if a further component, expanding $\propto a^{-3}$, breaks such stationary expansion at $z \sim 3$--$5 \times 10^3$, cosmic components gradually acquire densities consistent with observations. This paper, first of all, considers the case that this component is warm. However, its main topic is the analysis of fluctuation evolution: out of horizon modes are then determined; their entry into horizon is numerically evaluated as well as the dependence of Meszaros effect on the coupling $\beta$; finally, we compute: (i) transfer function and linear spectral function; (ii) CMB $C_l$ spectra. Both are close to standard $\Lambda$CDM models; in particular, the former one can be so down to a scale smaller than Milky Way, in spite of its main DM component being made of particles of mass $, Comment: 25 pages, 7 figures, accepted for publication on JCAP; updated to match the published version
- Published
- 2014
167. Constraints on Dark Energy state equation with varying pivoting redshift
- Author
-
Marino Mezzetti, Silvio A. Bonometto, Dario Scovacricchi, Giuseppe Vacca, D., Scovacricchi, S. A., Bonometto, Mezzetti, Marino, G., La Vacca, Scovacricchi, D, Bonometto, S, Mezzetti, M, and LA VACCA, G
- Subjects
Cosmological parameter ,State parameter ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,FOS: Physical sciences ,Ellipse ,Cosmology ,Dark Energy ,state equation ,Quantum mechanics ,Neutrino ,Instrumentation ,Physics ,Energy ,Astronomy and Astrophysics ,State (functional analysis) ,Astronomy and Astrophysic ,Dark ,Redshift ,Uncorrelated ,CosmoMC ,Space and Planetary Science ,Dark energy ,Atomic physics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We assume the DE state equations w(a) = w_0+w_a(a_p-a), and study the dependence of the constraints on w_0 and w_a coefficients on the pivoting redshift 1+z_p=1/a_p. Coefficients are fitted to data including WMAP7, SNIa (Union 2.1), BAO's (including WiggleZ and SDSS results) and H_0 constraints. The fitting algorithm is CosmoMC. We find specific differences between the cases when neutrino mass is allowed or disregarded. More in detail: i) The z_p value yielding uncorrelated constraints on w_0 and w_a is different in the two cases, holding ~0.25 and ~0.35, respectively. (ii) If we consider the intervals allowed to w_0, we find that they shift when z_p increases, in opposite directions for vanishing or allowed neutrino mass. This leads to no overlap between 1sigma intervals already at z_p >~0.4. (iii) The known effect that a more negative state parameter is required to allow for neutrino mass displays its effects on w_a, rather than on w_0. (iv) The w_0-w_a constraints found by using any pivot z_p can be translated into constraints holding at a specific z_p value (0 or the z_p where errors are uncorrelated). When we do so, error ellipses exhibit a satisfactory overlap., 13 pages, 7 figures, 2 tables
- Published
- 2012
168. Direct recovery of fluctuation spectra from tomographic shear spectra
- Author
-
G. Murante, Silvio A. Bonometto, Luciano Casarini, Marino Mezzetti, Mezzetti, Marino, Bonometto, S. A., Casarini, L., and Murante, G.
- Subjects
Physics ,gravitational lensing ,Spectral density ,Inverse ,Astronomy and Astrophysics ,power spectrum ,weak gravitational lensing ,Cosmology ,Spectral line ,Computational physics ,Gravitational lens ,Shear (geology) ,Singular value decomposition ,Weak gravitational lensing - Abstract
Forthcoming experiments will enable us to determine high precision tomographic shear spectra. Matter density fluctuation spectra, at various z, should then be recovered from them, in order to constrain the model and determine the DE state equation. Available analytical expressions, however, do the opposite, enabling us to derive shear spectra from fluctuation spectra. Here we find the inverse expression, yielding density fluctuation spectra from observational tomographic shear spectra. The procedure involves SVD techniques for matrix inversion. We show in detail how the approach works and provide a few examples.
- Published
- 2012
169. Non-linear weak lensing forecasts
- Author
-
Silvio A. Bonometto, Luca Amendola, Giuseppe La Vacca, Luciano Casarini, Andrea V. Macciò, Casarini, L, LA VACCA, G, Amendola, L, Bonometto, S, and Macciò, A
- Subjects
Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Estimation theory ,Degrees of freedom (physics and chemistry) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmological constant ,Astrophysics::Cosmology and Extragalactic Astrophysics ,weak gravitational lensing ,Cosmology ,Nonlinear system ,dark energy experiment ,Dark energy ,Statistical physics ,dark energy theory ,cosmological simulation ,Weak gravitational lensing ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We investigate the impact of non-linear corrections on dark energy parameter estimation from weak lensing probes. We find that using halofit expressions, suited to LCDM models, implies substantial discrepancies with respect to results directly obtained from N-body simulations, when w(z)\neq-1. Discrepancies appear strong when using models with w'(z=0)>0, as fiducial models; they are however significant even in the neighborhood of LCDM, where neglecting the degrees of freedom associated with the DE state equation can lead to a misestimate of the matter density parameter \Omega_m., Comment: 20 pages, 11 figures, accepted for publication in JCAP
- Published
- 2011
170. Mildly mixed coupled models vs. WMAP7 data
- Author
-
Silvio A. Bonometto, Giuseppe La Vacca, LA VACCA, G, and Bonometto, S
- Subjects
Physics ,High Energy Physics - Phenomenology ,Nuclear and High Energy Physics ,Coupling (physics) ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,High Energy Physics - Phenomenology (hep-ph) ,FOS: Physical sciences ,High Energy Physics::Experiment ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Molecular physics ,Atomic and Molecular Physics, and Optics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Mildly mixed coupled models include massive neutrinos and CDM--DE coupling. We present new tests of their likelihood vs. recent data including WMAP7, confirming it to exceed LCDM, although at ~2\sigma's. We then show the impact on the physics of the dark components of neutrino mass detection in tritium beta decay or neutrinoless double beta decay experiments., Comment: Proceedings of NOW2010, Conca Specchiulla, Italy, September 4-11, 2010
- Published
- 2011
- Full Text
- View/download PDF
171. Do data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?
- Author
-
S. A. Bonometto, G. La Vacca, J. R. Kristiansen, R. Mainini, L. P. L. Colombo, Jean-Michel Alimi, André Fuözfa, LA VACCA, G, Kristiansen, J, Colombo, L, Mainini, R, and Bonometto, S
- Subjects
Nuclear and High Energy Physics ,Particle physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Cold dark matter ,Dark matter ,Cosmic background radiation ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Cosmology ,Physics and Astronomy (all) ,FIS/05 - ASTRONOMIA E ASTROFISICA ,dynamical dark energy ,Coupling ,Physics ,Dark energy theory, dark matter, cosmological neutrinos, neutrino properties, cosmology of theories beyond the SM ,massive neutrino ,High Energy Physics::Phenomenology ,Astronomy and Astrophysics ,CMB cold spot ,Galaxy ,Atomic and Molecular Physics, and Optics ,Dark energy ,High Energy Physics::Experiment ,Neutrino ,Lepton ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Within the frame of cosmologies where Dark Energy (DE) is a self--interacting scalar field, we allow for a CDM--DE coupling and non--zero neutrino masses, simultaneously. In their 0--0 version, i.e. in the absence of coupling and neutrino mass, these cosmologies provide an excellent fit to WMAP, SNIa and deep galaxy sample spectra, at least as good as \LambdaCDM. When the new degrees of freedom are open, we find that CDM--DE coupling and significant neutrino masses (~0.1eV per \nu species) are at least as likely as the 0--0 option and, in some cases, even statistically favoured. Results are obtained by using a Monte Carlo Markov Chain approach., Comment: 18 pages, 10 figures, submitted to JCAP
- Published
- 2009
172. Dark matter-dark energy coupling biasing parameter estimates from cosmic microwave background data
- Author
-
Giuseppe Vacca, Luca Vergani, Silvio A. Bonometto, L. P. L. Colombo, LA VACCA, G, Colombo, L, Vergani, L, and Bonometto, S
- Subjects
Physics ,Cosmological parameter ,Cosmic microwave background ,Dark matter ,Cosmology: miscellaneou ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Parameter space ,Coupling (probability) ,Omega ,Cosmology ,Theoretical physics ,Cover (topology) ,Space and Planetary Science ,Dark energy - Abstract
When cosmic microwave background data are used to derive cosmological parameters, their very choice does matter: some parameter values can be biased if the parameter space does not cover the "true" model. This is a problem because of the difficulty in parameterizing dark energy (DE) physics. We test this risk through numerical experiments. We create artificial data for dynamical or coupled DE models and then use Monte Carlo Markov Chain techniques to recover model parameters by assuming a constant DE state parameter w and no DM-DE coupling. For the DE potential considered, no serious bias arises when coupling is absent. In contrast, ωo,c and thence Ho and Ωo,m suffer a serious bias when the "true" cosmology includes even just a mild DM-DE coupling. Until the nature of the dark components remains unknown, it can be important to allow for a degree of freedom accounting for DM-DE coupling, even more than increasing the number of parameters accounting for the w(a) behavior. © 2009. The American Astronomical Society. All rights reserved.
- Published
- 2009
173. Coupling between cold dark matter and dark energy from neutrino mass experiments
- Author
-
L. P. L. Colombo, R. Mainini, S. Bonometto, J. R. Kristiansen, G. La Vacca, Kristiansen, J, LA VACCA, G, Colombo, L, Mainini, R, and Bonometto, S
- Subjects
Physics ,Cosmological parameter ,Particle physics ,Cold dark matter ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Dark matter ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astronomy and Astrophysic ,Cosmology ,Cosmic microwave background ,Space and Planetary Science ,Dark energy ,Neutrino ,Instrumentation ,Light dark matter ,Dark fluid ,Astrophysics - Cosmology and Nongalactic Astrophysics ,KATRIN - Abstract
We consider cosmological models with dynamical dark energy (dDE) coupled to cold dark matter (CDM), while simultaneously allowing neutrinos to be massive. Using a MCMC approach, we compare these models with a wide range of cosmological data sets. We find a strong correlation between this coupling strength and the neutrino mass. This correlation persists when BAO data are included in the analysis. We add then priors on $\nu$ mass from particle experiments. The claimed detection of $\nu$ mass from the Heidelberg-Moscow neutrinoless double--$\beta$ decay experiment would imply a 7--$8 \sigma$ detection of CDM-DE coupling. Similarly, the detection of $\nu$ mass from coming KATRIN tritium $\beta$ decay experiment will imply a safe detection of a coupling in the dark sector. Previous attempts to accommodate cosmic phenomenology with such possible $\nu$ mass data made recourse to a $w < -1$ eoS. We compare such an option with the coupling option and find that the latter allows a drastic improvement., Comment: 12 pages, accepted for publication in New Astronomy
- Published
- 2009
- Full Text
- View/download PDF
174. Dynamical Dark Energy simulations: high accuracy Power Spectra at high redshift
- Author
-
Silvio A. Bonometto, Luciano Casarini, Andrea V. Macciò, Casarini, L, Maccio', A, and Bonometto, S
- Subjects
Physics ,Series (mathematics) ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,cosmological simulations, gravitational lensing, power spectrum ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Spectral line ,Redshift ,Computational physics ,Gravitation ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Cover (topology) ,Dark energy ,Range (statistics) ,Constant (mathematics) - Abstract
Accurate predictions on non--linear power spectra, at various redshift z, will be a basic tool to interpret cosmological data from next generation mass probes, so obtaining key information on Dark Energy nature. This calls for high precision simulations, covering the whole functional space of w(z) state equations and taking also into account the admitted ranges of other cosmological parameters; surely a difficult task. A procedure was however suggested, able to match the spectra at z=0, up to k~3, hMpc^{-1}, in cosmologies with an (almost) arbitrary w(z), by making recourse to the results of N-body simulations with w = const. In this paper we extend such procedure to high redshift and test our approach through a series of N-body gravitational simulations of various models, including a model closely fitting WMAP5 and complementary data. Our approach detects w= const. models, whose spectra meet the requirement within 1% at z=0 and perform even better at higher redshift, where they are close to a permil precision. Available Halofit expressions, extended to (constant) w \neq -1 are unfortunately unsuitable to fit the spectra of the physical models considered here. Their extension to cover the desired range should be however feasible, and this will enable us to match spectra from any DE state equation., method definitely improved in semplicity and efficacy,accepted for publication on JCAP
- Published
- 2008
175. Tracking through equality
- Author
-
Silvio A. Bonometto, Giandomenico Sassi, Sassi, G, and Bonometto, S
- Subjects
Physics ,Epoch (reference date) ,Supergravity ,Astrophysics (astro-ph) ,quintessence ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Tracking (particle physics) ,Astrophysics ,Cosmology ,Theoretical physics ,FIS/05 - ASTRONOMIA E ASTROFISICA ,General Relativity and Quantum Cosmology ,Classical mechanics ,Space and Planetary Science ,dark energy ,Instrumentation ,Scalar field ,Quintessence - Abstract
We give a tracker solution for the quintessence scalar field for Ratra--Peebles or SUGRA potentials, holding before, during and after the equality epoch (\rho_m=\rho_r) and nicely fitting the numerical behavior., Comment: submitted to New Astronomy
- Published
- 2006
176. The Sky Polarization Observatory (SPOrt) Programme
- Author
-
Sergio Poppi, S. Cecchini, M. Baralis, M. Zannoni, C. Sbarra, E. Carretti, Jader Monari, Razin, M. Gervasi, M. Tucci, R. Tascone, Luciano Nicastro, Gianni Bernardi, Alessandro Orfei, Claudio Macculi, O. A. Peverini, S. Bonometto, I. A. Strukov, R. Fabbri, Stefano Cortiglioni, M. V. Sazhin, Kin-Wang Ng, G. Boella, E. N. Vinyajkin, G. Sironi, Carretti, E, Cortiglioni, S, Bernardi, G, Cecchini, S, Macculi, C, Sbarra, C, Monari, J, Orfei, A, Poppi, S, Boella, G, Bonometto, S, Gervasi, M, Sironi, G, Zannoni, M, Tucci, M, Baralis, M, Peverini, O, Tascone, R, Fabbri, R, Nicastro, L, Ng, K, Razin, V, Vinyajkin, E, Sazhin, M, and Strukov, I
- Subjects
Physics ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Sky ,Observatory ,media_common.quotation_subject ,Astronomy ,cosmology, polarization, CMB, space ,Polarization (waves) ,media_common ,Remote sensing - Abstract
SPOrt is an experiment aimed at making a polarization survey of the sky in the microwave range (22-90 GHz) on large angular scales (FWHM = 7degrees).
- Published
- 2006
177. BaR-SPOrt experiment: measuring the CMBP E-mode power spectrum from Dome C
- Author
-
M. Baralis, S. Cecchini, E. Carretti, Massimo Gervasi, M. V. Sazhin, Giuseppe Virone, L. P. L. Colombo, C. Sbarra, Jader Monari, M. De Petris, M. Ramponi, Stefano Cortiglioni, Sergio Poppi, Luciano Casarini, Gianni Bernardi, P. de Bernardis, Silvia Masi, O. A. Peverini, V. Natale, M. Poloni, G. Sironi, Silvio A. Bonometto, R. Fabbri, Renzo Nesti, A. Boscaleri, G. Ventura, R. Tascone, Luciano Nicastro, Claudio Macculi, M. Zannoni, E. N. Vinyajkin, Carretti, E, Cortiglioni, S, Bernardi, G, Casarini, L, Cecchini, S, Macculi, C, Ramponi, M, Sbarra, C, Ventura, G, Monari, J, Poloni, M, Poppi, S, Baralis, M, Peverini, O, Tascone, R, Virone, G, Zannoni, M, Bonometto, S, Colombo, L, Gervasi, M, Sironi, G, Fabbri, R, Natale, V, Nesti, R, Nicastro, L, de Bernardis, P, Masi, S, de Petris, M, Boscaleri, A, Sazhin, M, and Vinyajkin, E
- Subjects
Physics ,Current configuration ,media_common.quotation_subject ,Cosmic microwave background ,Astrophysics::Instrumentation and Methods for Astrophysics ,General Engineering ,Spectral density ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Low frequency ,Polarization (waves) ,Dust emissions ,Cosmology ,Synchrotron emission ,Space and Planetary Science ,Sky ,Cosmic Microwave Background ,POLARIZATION, CMB, COSMOLOGY ,Multipole expansion ,Astrophysics::Galaxy Astrophysics ,media_common - Abstract
The BaR-SPOrt experiment is designed to measure the E -mode power spectrum of the Cosmic Microwave Background Polarization (CMBP) in the multipole range 50 l < 1000. In the current configuration at 32 GHz it can explore up to l = 400. Recent low frequency observations of the target region show that the synchrotron emission should not contamine the CMBP already at 32 GHz. A 6-month observation of a 6° × 6° sky area during the polar night, in ideal environmental conditions, will allow the Italian-French collaboration to both measure the E –mode power spectrum with appropriate sensitivity and perform important tests of the anomalous dust emission. The BaR-SPOrt 32 GHz instrument, now under test and ready for operations by Spring 2005, is proposed for 1–2 years Winter operations at Dome C.
- Published
- 2005
178. The Sky Polarisation Observatory (SPOrt) Program
- Author
-
M. Zannoni, M. Tucci, G. Boella, S. Cecchini, R. Tascone, M. Orsini, G. Sironi, Luciano Nicastro, Sergio Poppi, Claudio Macculi, Stefano Cortiglioni, S. Bonometto, R. Fabbri, U. Pisani, Alessandro Orfei, M. Gervasi, Jader Monari, E. Carretti, Carretti, E, Cortiglioni, S, Tucci, M, Cecchini, S, Macculi, C, Orsini, M, Monari, J, Orfei, A, Poppi, S, Bonometto, S, Boella, G, Gervasi, M, Sironi, G, Zannoni, M, Fabbri, R, Nicastro, L, Tascone, R, and Pisani, U
- Subjects
Physics ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Observatory ,Sky ,media_common.quotation_subject ,Polarimetry ,Astronomy ,CMB ,media_common ,Remote sensing ,Cosmology - Abstract
The main goal of the Sky Polarization Observatory (SPOrt) Program is the measurement of the sky linear polarized emission in the 22-90 GHz frequency range. SPOrt payload will be accommodated on the International Space Station in 2003-2004 for a period of 18 months. The instrument configuration is presented together with most relevant ground activities in support to its realization. In particular, the development of hardware solutions for high sensitive polarimetric measurements, such as those requested by Galactic polarized emission and Cosmic Microwave Background observations, has been addressed by the SPOrt team to match the experiment requirements.
- Published
- 2005
179. The Sky Polarization Observatory
- Author
-
R. Fabbri, Silvio A. Bonometto, V.A. Razin, M. V. Sazhin, M. Ramponi, L. P. L. Colombo, M. Baralis, Oscar Antonio Peverini, R. Tascone, Kin-Wang Ng, Luciano Nicastro, V. Natale, Claudio Macculi, Luciano Casarini, C. Sbarra, Gianni Bernardi, Mario Zannoni, M. Poloni, B. Negri, G. Sironi, E. Carretti, Sergio Poppi, S. Cecchini, Jader Monari, Alessandro Orfei, Massimo Gervasi, Giuseppe Virone, I. A. Strukov, Stefano Cortiglioni, G. Boella, E. N. Vinyajkin, Cortiglioni, S, Bernardi, G, Carretti, E, Casarini, L, Cecchini, S, Macculi, C, Ramponi, M, Sbarra, C, Monari, J, Orfei, A, Poloni, M, Poppi, S, Boella, G, Bonometto, S, Colombo, L, Gervasi, M, Sironi, G, Zannoni, M, Baralis, M, Peverini, O, Tascone, R, Virone, G, Fabbri, R, Natale, V, Nicastro, L, Ng, K, Vinyajkin, E, Razin, V, Sazhin, M, Strukov, I, and Negri, B
- Subjects
ANGULAR POWER SPECTRUM ,SCANNING STRATEGY ,media_common.quotation_subject ,Cosmic microwave background ,Polarimetry ,Cosmic background radiation ,FOS: Physical sciences ,Astrophysics ,FIS/05 - ASTRONOMIA E ASTROFISICA ,symbols.namesake ,Observatory ,Observational cosmology ,Stokes parameters ,Cosmic microwave background, Polarization, Cosmology: observations ,Instrumentation ,media_common ,Physics ,Astrophysics (astro-ph) ,Astronomy ,Astronomy and Astrophysics ,GALACTIC SYNCHROTRON ,Polarization (waves) ,Space and Planetary Science ,Sky ,PROBE WMAP OBSERVATIONS ,symbols ,MICROWAVE BACKGROUND POLARIZATION - Abstract
SPOrt is an ASI-funded experiment specifically designed to measure the sky polarization at 22, 32 and 90 GHz, which was selected in 1997 by ESA to be flown on the International Space Station. Starting in 2006 and for at least 18 months, it will be taking direct and simultaneous measurements of the Stokes parameters Q and U at 660 sky pixels, with FWHM=7 degrees. Due to development efforts over the past few years, the design specifications have been significantly improved with respect to the first proposal. Here we present an up-to-date description of the instrument, which now warrants a pixel sensitivity of 1.7 microK for the polarization of the cosmic background radiation, assuming two years of observations. We discuss SPOrt scientific goals in the light of WMAP results, in particular in connection with the emerging double-reionization cosmological scenario., 53 pages, 22 figures, 1 reference replaced
- Published
- 2004
180. The BaR-SPOrt experiment
- Author
-
S. Bonometto, Giuseppe Virone, Gianni Bernardi, S. Cecchini, Sergio Poppi, R. Fabbri, M. Tucci, M. Baralis, Jader Monari, Silvia Masi, M. Poloni, Enzo Pascale, P. de Bernardis, E. Morelli, E. N. Vinyajkin, M. Gervasi, Stefano Cortiglioni, A. Boscaleri, G. Ventura, R. Tascone, M. V. Sazhin, Luciano Nicastro, G. Boella, Claudio Macculi, Renzo Nesti, M. De Petris, E. Carretti, O. A. Peverini, V. Natale, G. Sironi, C. Sbarra, Mario Zannoni, Fineschi, S, Zannoni, M, Cortiglioni, S, Bernardi, G, Carretti, E, Cecchini, S, Macculi, C, Morelli, E, Sbarra, C, Ventura, G, Nicastro, L, Monari, J, Poloni, M, Poppi, S, Natale, V, Baralis, M, Peverini, O, Tascone, R, Virone, G, Boscaleri, A, Pascale, E, Boella, G, Bonometto, S, Gervasi, M, Sironi, G, Tucci, M, Nesti, R, Fabbri, R, De Bernardis, P, De Petris, M, Masi, S, Sazhin, M, and Vinyajkin, E
- Subjects
LDB ,media_common.quotation_subject ,Cosmic microwave background ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,CMB ,law.invention ,Telescope ,FIS/05 - ASTRONOMIA E ASTROFISICA ,symbols.namesake ,law ,Polarization ,Stokes parameters ,Angular resolution ,BaR-SPOrt ,Electrical and Electronic Engineering ,Astrophysics::Galaxy Astrophysics ,Remote sensing ,media_common ,Physics ,experiment ,Radiometer ,Linear polarization ,Astrophysics (astro-ph) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Instrument ,Condensed Matter Physics ,Polarization (waves) ,Sky ,symbols - Abstract
BaR-SPOrt (Balloon-borne Radiometers for Sky Polarisation Observations) is an experiment to measure the linearly polarized emission of sky patches at 32 and 90 GHz with sub-degree angular resolution. It is equipped with high sensitivity correlation polarimeters for simultaneous detection of both the U and Q stokes parameters of the incident radiation. On-axis telescope is used to observe angular scales where the expected polarization of the Cosmic Microwave Background (CMBP) peaks. This project shares most of the know-how and sophisticated technology developed for the SPOrt experiment onboard the International Space Station. The payload is designed to flight onboard long duration stratospheric balloons both in the Northern and Southern hemispheres where low foreground emission sky patches are accessible. Due to the weakness of the expected CMBP signal (in the range of microK), much care has been spent to optimize the instrument design with respect to the systematics generation, observing time efficiency and long term stability. In this contribution we present the instrument design, and first tests on some components of the 32 GHz radiometer., Comment: 12 pages, 10 figures, Astronomical Telescopes and Instrumentation (Polaimetry in Astronomy) Hawaii August 2002 SPIE Meeting
- Published
- 2003
181. BaR-SPOrt: Balloon-Borne Radiometers for Sky Polarization Observations
- Author
-
S. Cecchini, R. Fabbri, Sergio Poppi, S. Bonometto, A. Boscaleri, O. A. Peverini, G. Ventura, Natale, Gianni Bernardi, R. Tascone, E. N. Vinyajkin, Luciano Nicastro, Enzo Pascale, M. Baralis, Claudio Macculi, E. Carretti, G. Boella, M. V. Sazhin, C. Sbarra, Jader Monari, Renzo Nesti, M. De Petris, G. Sironi, Silvia Masi, M. Tucci, R. Di Raffaele, M. Gervasi, M. Zannoni, P. de Bernardis, Stefano Cortiglioni, Sbarra, C, Cortiglioni, S, Bernardi, G, Carretti, E, Cecchini, S, Macculi, C, Ventura, G, Baralis, M, Peverini, O, Tascone, R, Boella, G, Bonometto, S, Gervasi, M, Sironi, G, Tucci, M, Zannoni, M, Natale, V, Nesti, R, Fabbri, R, Monari, J, Poppi, S, Nicastro, L, di Raffaele, R, Boscaleri, A, Pascale, E, de Bernardis, P, de Petris, M, Masi, S, Sazhin, M, and Vinyajkin, E
- Subjects
Physics ,Radiometer ,Astronomy ,media_common.quotation_subject ,Polarization (waves) ,Balloon ,Cosmology ,Astrophysic ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Sky ,Polarization ,Cosmic Microwave Background ,Remote sensing ,media_common - Abstract
BaR-SPOrt, funded by ASI (Italian Space Agency), is a 32 (90) GHz balloon-borne correlation polarimeter for direct measurements of the Q and U Stokes parameters, with an angular resolution of 0.6° (0.2°). Aim of the experiment is the detection of the polarized emission of the diffuse Galactic Background and the Cosmic Microwave Background (CMB). The most likely launch site is Antarctica (2 to 4-week flight). Kiruna (Sweden, 1-week flight) and Svalbard (Norway, > 1-week flight) are possible launch site to observe the Northern sky
- Published
- 2003
182. SPOrt: An experiment aimed at measuring the large scale cosmic microwave background polarization
- Author
-
V.A. Razin, Riccardo Tascone, M. V. Sazhin, M. Tucci, R. Fabbri, C. Sbarra, Mario Zannoni, Silvio A. Bonometto, A. Orfei, Ettore Carretti, Kin-Wang Ng, S. Cecchini, M. Poloni, G. Sironi, Sergio Poppi, M. Baralis, Jader Monari, Oscar Antonio Peverini, Luciano Nicastro, Claudio Macculi, G. Boella, Massimo Gervasi, Giuseppe Virone, Gianni Bernardi, I. A. Strukov, Stefano Cortiglioni, E. N. Vinyajkin, Fineschi S., Carretti, E, Cortiglioni, S, Bernardi, G, Cecchini, S, Macculi, C, Sbarra, C, Monari, J, Orfei, A, Poloni, M, Poppi, S, Boella, G, Bonometto, S, Gervasi, M, Sironi, G, Zannoni, M, Tucci, M, Baralis, M, Peverini, O, Tascone, R, Virone, G, Fabbri, R, Nicastro, L, Ng, K, Razin, V, Vinyajkin, E, Sazhin, M, and Strukov, I
- Subjects
DEVICES ,media_common.quotation_subject ,COSMOLOGICAL PARAMETERS ,Cosmic microwave background ,Phase (waves) ,UNIVERSE ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Signal ,GRAVITATIONAL-WAVES ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Optics ,Observatory ,GHZ ,Astrophysics::Galaxy Astrophysics ,media_common ,Physics ,ANISOTROPY ,Radiometer ,business.industry ,Astrophysics (astro-ph) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Polarization (waves) ,DEGREE ANGULAR SCALES ,RESOLUTION ,Sky ,RADIATION ,business ,EMISSION ,Microwave - Abstract
SPOrt (Sky Polarization Observatory) is a space experiment to be flown on the International Space Station during Early Utilization Phase aimed at measuring the microwave polarized emission with FWHM = 7deg, in the frequency range 22-90 GHz. The Galactic polarized emission can be observed at the lower frequencies and the polarization of Cosmic Microwave Background (CMB) at 90 GHz, where contaminants are expected to be less important. The extremely low level of the CMB Polarization signal (< 1 uK) calls for intrinsically stable radiometers. The SPOrt instrument is expressly devoted to CMB polarization measurements and the whole design has been optimized for minimizing instrumental polarization effects. In this contribution we present the receiver architecture based on correlation techniques, the analysis showing its intrinsic stability and the custom hardware development carried out to detect such a low signal., 9 pages, 5 figures, conference proceeding, to appear in "Polarimetry in Astronomy", SPIE Symposium on 'Astronomical Telescopes and Instrumentation', Waikoloa, August 22-28 2002
- Published
- 2003
183. Path-integral approach to large-scale matter distribution originated by non-Gaussian fluctuations
- Author
-
Bonometto, S
- Published
- 1986
- Full Text
- View/download PDF
184. Theoretical aspects of the gamma emission of galactic nuclei
- Author
-
Bonometto, S
- Published
- 1974
185. BaR-SPOrt: A technical overview
- Author
-
Enzo Pascale, C. Sbarra, Sergio Poppi, S. Bonometto, S. Cecchini, G. Ventura, M. Zannoni, R. Tascone, Luciano Nicastro, Stefano Cortiglioni, M. Baralis, Claudio Macculi, Gianni Bernardi, R. Fabbri, G. Sironi, M. Bruscoli, G. Boella, E. Morelli, Jader Monari, M. Gervasi, A. Boscaleri, O. A. Peverini, V. Natale, M. Tucci, E. Carretti, Macculi, C, Bernardi, G, Carretti, E, Cecchini, S, Cortiglioni, S, Morelli, E, Sbarra, C, Ventura, G, Monari, J, Poppi, S, Boella, G, Bonometto, S, Gervasi, M, Sironi, G, Tucci, M, Zannoni, M, Baralis, M, Peverini, O, Tascone, R, Fabbri, R, Natale, V, Bruscoli, M, Boscaleri, A, Pascale, E, and Nicastro, L
- Subjects
CMB, Polarimetry, Cosmology, LDB ,Physics ,Radiometer ,business.industry ,Linear polarization ,media_common.quotation_subject ,Astrophysics::Instrumentation and Methods for Astrophysics ,Cosmic background radiation ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Polarization (waves) ,FIS/05 - ASTRONOMIA E ASTROFISICA ,symbols.namesake ,Optics ,Sky ,Observational cosmology ,symbols ,Stokes parameters ,business ,Astrophysics::Galaxy Astrophysics ,media_common ,Stratospheric balloon - Abstract
BaR-SPOrt is a project to measure the linearly polarised emission of 20degtimes20deg sky patches from a stratospheric balloon, at 32 GHz and 90 GHz. It consists of correlation polarimeters for direct measurements of the Q and U Stokes parameters, coupled to optics providing a beam of 0.5deg (32 GHz) and 0.2deg (90 GHz). The instrument design is described. Particular emphasis is put on the hardware solutions adopted to reduce the systematic effects in high sensitivity polarisation measurements
- Published
- 2002
186. QUANTUM TREATMENT OF ELECTRON EMISSION IN A STRONG ELECTROMAGNETIC WAVE.
- Author
-
Bonometto, S
- Published
- 1971
187. On gauge invariance for a neutral massive vector field
- Author
-
Bonometto, S.
- Published
- 1963
- Full Text
- View/download PDF
188. MEASUREMENT INVARIANTS FOR STRONG INTERACTIONS WITH TETRADIMENSIONAL ISOBARIC SYMMETRY
- Author
-
Bonometto, S
- Published
- 1961
189. TRANSPARENCY OF EXTRAGALACTIC SPACE TO VERY-HIGH-ENERGY PHOTONS. II.
- Author
-
Bonometto, S
- Published
- 1971
- Full Text
- View/download PDF
190. MINIMAL ELECTROMAGNETIC COUPLING OF VECTOR MESONS
- Author
-
Bonometto, S
- Published
- 1964
- Full Text
- View/download PDF
191. Dark energy from dark radiation in strongly coupled cosmologies with no fine tuning
- Author
-
Silvio A. Bonometto, Giandomenico Sassi, Giuseppe La Vacca, Bonometto, S, Sassi, G, and LA VACCA, G
- Subjects
Physics ,dark matter theory ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Dark matter ,FOS: Physical sciences ,Astronomy and Astrophysics ,Kinetic energy ,Cosmology ,Computational physics ,Galactic halo ,Gravitation ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Dark radiation ,Dark energy ,physics of the early universe ,dark energy theory ,cosmology of theories beyond the SM ,Scalar field ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
A dual component made of non-relativistic particles and a scalar field, exchanging energy, naturally falls onto an attractor solution, making them a (sub)dominant part of the cosmic energy during the radiation dominated era, provided that the constant \beta, measuring the coupling, is strong enough. The density parameters of both components are then constant, as they expand as a^{-4}. If the field energy is then prevalently kinetic, as is expected, its energy is exactly half of the pressureless component; the dual component as a whole, then, has a density parameter \Omega_{cd} = 3/4\beta^2 (e.g., for \beta~2.5, \Omega_{cd}~0.1, in accordance with Dark Radiation expectations). The stationary evolution can only be broken by the rising of other component(s), expanding as a^{-3}. In a realistic scenario, this happens when z~3-5x10^3. When such extra component(s) become(s) dominant, the densities of the dual components also rise above radiation. The scalar field behavior can be easily tuned to fit Dark Energy data, while the coupled DM density parameter becomes O(10^{-3}). This model however requires that, at present, two different DM components exist. The one responsible for the break of the stationary regime could be made, e.g., by thermally distributed particles with mass even >>1$-2 keV (or non-thermal particles with analogous average speed) so accounting for the size of observed galactic cores; in fact, a fair amount of small scale objects is however produced by fluctuation re-generated by the coupled DM component, in spite of its small density parameter, after the warm component has become non-relativistic., Comment: 19 pages, 6 figures, JCAP published
- Published
- 2012
192. Biased theories of galaxy formation with arbitrary threshold functions and background distribution
- Author
-
Silvio A. Bonometto, Stefano Borgani, Borgani, Stefano, and Bonometto, S.
- Subjects
Physics ,COMPUTATIONAL ASTROPHYSICS ,Mass distribution ,MASS DISTRIBUTION ,Gaussian ,ASTRONOMICAL CATALOGS ,GALACTIC EVOLUTION ,Astronomy and Astrophysics ,Astrophysics ,Correlation function (astronomy) ,Galaxy ,Cosmology ,PROBABILITY DISTRIBUTION FUNCTIONS ,symbols.namesake ,Galaxy groups and clusters ,Space and Planetary Science ,COSMOLOGY ,symbols ,Galaxy formation and evolution ,GALACTIC CLUSTERS ,Galaxy cluster - Abstract
The technical aspects of considering non-theta thresholds within the framework of biased theories of galaxy formation are discussed, without restricting the treatment to background Gaussian matter distribution. First, non-Gaussian backgrounds and non-theta thresholds are simultaneously considered. Then a number of other features are accounted for through suitable forms of threshold functions. Two specific examples of non-theta thresholds relate directly to the effects of nonspherical gravitational growing and a possible merging of fluctuations on different mass scales during the growing stages. It appears that these effects become stronger for mass scales corresponding to Abell cluster mass scale range. In particular, the threshold related to nonsphericity makes the observed number densities of Turner and Gott groups and Abell cluster naturally coherent. 49 refs.
- Published
- 1990
193. The SPOrt experiment
- Author
-
Gianni Bernardi, G. Sironi, M. Tucci, S. Cecchini, M. V. Sazhin, V.A. Razin, Kin-Wang Ng, R. Tascone, M. Bruscoli, Luciano Nicastro, O. A. Peverini, Claudio Macculi, R. Fabbri, E. N. Vinyajkin, S. Bonometto, M. Gervasi, I. A. Strukov, Stefano Cortiglioni, Sergio Poppi, Alessandro Orfei, E. Carretti, C. Sbarra, Mario Zannoni, M. Baralis, G. Boella, Jader Monari, Cecchini, S, Cortiglioni, S, Sault, R, Sbarra, C, Carretti, E, Baralis, M, Bernardi, G, Boella, G, Bonometto, S, Bruscoli, M, Fabbri, R, Gervasi, M, Macculi, C, Monari, J, Ng, K, Nicastro, L, Orfei, A, Peverini, O, Poppi, S, Razin, V, Sazhin, M, Sironi, G, Strukov, I, Tascone, R, Tucci, M, Vinyajkin, E, and Zannoni, M
- Subjects
Physics ,ANISOTROPY ,COSMOLOGICAL PARAMETERS ,Cosmic microwave background ,Astrophysics::Instrumentation and Methods for Astrophysics ,Cosmic background radiation ,Astronomy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Polarization (waves) ,DEGREE ANGULAR SCALES ,LIMIT ,Galaxy ,GRAVITATIONAL-WAVES ,FIS/05 - ASTRONOMIA E ASTROFISICA ,RESOLUTION ,GHZ ,MAPS ,Microwave range ,RADIATION ,Space research ,MICROWAVE BACKGROUND POLARIZATION ,Astrophysics::Galaxy Astrophysics - Abstract
SPOrt is a space experimental aimed at studying the polarization of the CMB and of the diffused Galactic Background in the microwave range (22-90 GHz). Here we present the project as well as its main scientific goals.
194. The BaR-SPOrt experiment: the science
- Author
-
G. Boella, S. Bonometto, Stefano Cortiglioni, M. Bruscoli, R. Fabbri, Enzo Pascale, S. Cecchini, E. Carretti, A. Boscaleri, Jader Monari, M. Baralis, Sergio Poppi, M. Gervasi, E. Morelli, G. Sironi, C. Sbarra, Gianni Bernardi, M. Tucci, O. A. Peverini, V. Natale, G. Ventura, R. Tascone, Luciano Nicastro, Claudio Macculi, M. Zannoni, DePetris, M, Gervasi, M, Carretti, E, Bernardi, G, Cecchini, S, Cortiglioni, S, Macculi, C, Morelli, E, Sbarra, C, Ventura, G, Monari, J, Poppi, S, Boella, G, Bonometto, S, Sironi, G, Tucci, M, Zannoni, M, Baralis, M, Peverini, O, Tascone, R, Fabbri, R, Natale, V, Bruscoli, M, Boscaleri, A, Pascale, E, and Nicastro, L
- Subjects
Physics ,FIS/05 - ASTRONOMIA E ASTROFISICA ,Cosmic microwave background ,Astrophysics::Instrumentation and Methods for Astrophysics ,Cosmic background radiation ,Astronomy ,Microwave range ,CMB, Polarimetry, COSMOLOGY ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Polarization (waves) ,Astrophysics::Galaxy Astrophysics - Abstract
BaR-SPOrt is a balloon-borne experiment in the microwave range (32–90 GHz) aimed at studying the polarization of the CMB and of the diffused Galactic Background. Here we present the main scientific goals as well as the observing strategies of the project.
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.