L\u2019 Etna: un percorso attraverso l\u2019immaginario, la consapevolezza del rischio e la gestione del territorio\u201d,

anche in, Annali della Facolt\ue0 di Economia, Catania, anno L, 2004

Thermal decoupling and the smallest subhalo mass in dark matter models with Sommerfeld-enhanced annihilation rates

We consider dark matter consisting of weakly interacting massive particles (WIMPs) and revisit in detail its thermal evolution in the early universe, with a particular focus on models where the annihilation rate is enhanced by the Sommerfeld effect. After chemical decoupling, or freeze-out, dark matter no longer annihilates but is still kept in local thermal equilibrium due to scattering events with the much more abundant standard model particles. During kinetic decoupling, even these processes stop to be effective, which eventually sets the scale for a small-scale cutoff in the matter density fluctuations. Afterwards, the WIMP temperature decreases more quickly than the heat bath temperature, which causes dark matter to reenter an era of annihilation if the cross-section is enhanced by the Sommerfeld effect. Here, we give a detailed and self-consistent description of these effects. As an application, we consider the phenomenology of simple leptophilic models that have been discussed in the literature and find that the relic abundance can be affected by as much two orders of magnitude or more. We also compute the mass of the smallest dark matter subhalos in these models and find it to be in the range of about 10^{-10} to 10 solar masses; even much larger cutoff values are possible if the WIMPs couple to force carriers lighter than about 100 MeV. We point out that a precise determination of the cutoff mass allows to infer new limits on the model parameters, in particular from gamma-ray observations of galaxy clusters, that are highly complementary to existing constraints from g-2 or beam dump experiments.Comment: minor changes to match published versio

Presenting the Compendium Isotoporum Medii Aevi, a multi-isotope database for Medieval Europe

Here we present the Compendium Isotoporum Medii Aevi (CIMA), an open-access database gathering more than 50,000 isotopic measurements for bioarchaeological samples located within Europe and its margins, and dating between 500 and 1500 CE. This multi-isotope (δ13C, δ15N, δ34S, δ18O, and 87Sr/86Sr) archive of measurements on human, animal, and plant archaeological remains also includes a variety of supporting information that offer, for instance, a taxonomic characterization of the samples, their location, and chronology, in addition to data on social, religious, and political contexts. Such a dataset can be used to identify data gaps for future research and to address multiple research questions, including those related with studies on medieval human lifeways (i.e. human subsistence, spatial mobility), characterization of paleo-environmental and -climatic conditions, and on plant and animal agricultural management practices. Brief examples of such applications are given here and we also discuss how the integration of large volumes of isotopic data with other types of archaeological and historical data can improve our knowledge of medieval Europe.Background & Summary Methods Data Records Technical Validation Usage Note

Territory and memory: The Landing of the Allies in Sicily in 1943

The concept of memory (memorial site) has gained crucial importance in recent years for the identification of places (areas) and in the affirmation of local identities. The memorial sites are areas where usually tragic events have occurred and resulted in a cultural change. In these places there are still signs of these historical events and/or tangible and intangible indications created by the society such as: monuments, obelisks, marble inscriptions, others. Sicily represents an ideal area for studying memorial sites; not only because of the number of dominations in the past centuries, but also for the significance of all places where the mafia has taken its root. These elements have caused several changes in the culture and in the landscape. Sicily is the land where \u201cOperation Husky\u201d began, in the summer of 1943. This agreement between the Americans and the British aimed at occupying Sicily, Italy after World War II. Seventy years after this operation the territory is still marked by testimonies of those tragic events. The bombing devastated buildings, which we can still acknowledge for their cultural significance. These memorial areas represent a strong testimony of the past. There are cemeteries, protecting bodies many of which are unknown; there are bunkers and other military garrisons well preserved throughout the territory. These signs must be rediscovered, to be replicated because of the contemporary geopolitical situation. As a result, in this paper we propose to identify the area of eastern Sicily suitable for a tourist itinerary in the cultural memory of the war of 1943. The idea is to encourage tourism that gives rise to real emotions and thoughts

PAMELA and FERMI-LAT limits on the neutralino-chargino mass degeneracy

Searches for Dark Matter (DM) particles with indirect detection techniques have reached important milestones with the precise measurements of the anti-proton and gamma-ray spectra, notably by the PAMELA and FERMI-LAT experiments. While the gamma-ray results have been used to test the thermal Dark Matter hypothesis and constrain the Dark Matter annihilation cross section into Standard Model (SM) particles, the anti-proton flux measured by the PAMELA experiment remains relatively unexploited. Here we show that the latter can be used to set a constraint on the neutralino-chargino mass difference. To illustrate our point we use a Supersymmetric model in which the gauginos are light, the sfermions are heavy and the Lightest Supersymmetric Particle (LSP) is the neutralino. In this framework the W^+ W^- production is expected to be significant, thus leading to large anti-proton and gamma-ray fluxes. After determining a generic limit on the Dark Matter pair annihilation cross section into W^+ W^- from the anti-proton data only, we show that one can constrain scenarios in which the neutralino-chargino mass difference is as large as ~ 20 GeV for a mixed neutralino (and intermediate choices of the anti-proton propagation scheme). This result is consistent with the limit obtained by using the FERMI-LAT data. As a result, we can safely rule out the pure wino neutralino hypothesis if it is lighter than 450 GeV and constitutes all the Dark Matter.Comment: 22page

Robust implications on Dark Matter from the first FERMI sky gamma map

We derive robust model-independent bounds on DM annihilations and decays from the first year of FERMI gamma-ray observations of the whole sky. These bounds only have a mild dependence on the DM density profile and allow the following DM interpretations of the PAMELA and FERMI electron/positron excesses: primary channels mu+ mu-, mu+ mu-mu+mu- or e+ e- e+ e-. An isothermal-like density profile is needed for annihilating DM. In all such cases, FERMI gamma spectra must contain a significant DM component, that may be probed in the future.Comment: 16 pages, 8 figures. Final versio

Small steps towards Grand Unification and the electron/positron excesses in cosmic-ray experiments

We consider a small extension of the standard model by adding two Majorana fermions; those are adjoint representations of the SU(2)_L and SU(3)_c gauge groups of the standard model. In this extension, the gauge coupling unification at an energy scale higher than 10^{15} GeV is realized when the masses of the triplet and the octet fermions are smaller than 10^4 GeV and 10^{12} GeV, respectively. We also show that an appropriate symmetry ensures a long lifetime of the neutral component of the triplet fermion whose thermal relic density naturally explains the observed dark matter density. The electron/positron excesses observed in recent cosmic-ray experiments can be also explained by the decay of the triplet fermion.Comment: 11 pages, 5 figure