Induced gravity on intersecting brane-worlds Part I: Maximally symmetric solutions

We explore models of intersecting brane-worlds with induced gravity terms on codimension one branes and on their intersection. Maximally symmetric solutions for the branes and the intersection are found. We find new self-accelerating solutions. In a 6d spacetime, the solutions realize the see-saw modification of gravity where the UV scale of the modification to 4d gravity is determined by 6d Planck scale given by $M_6 \sim 10^{-3}$eV and the IR scale of the modification is determined by $M_6^2/M_4 \sim H_0 \sim 10^{-42}$ GeV where $H_0$ is present-day Hubble scale. We find that it is increasingly difficult to construct phenomenologically viable models in higher-dimensional spacetime due to the necessity to have the lower value for the fundamental Planck scale to realize the late time acceleration. It is found that the system also admits self-tuning solutions where the tension at the intersection does not change the geometry of the intersection. The induced gravity terms can avoid the necessity to compactify the extra dimensions. Finally, we discuss the possibility to have ordinary matter at the intersection, without introducing any regularisation, using the induced gravity terms.Comment: 16 pages, some mistakes in the identification of the higher codimensional singular structure corrected. Main results unchange

The multimedia technologies and the new realities for knowledge networking and valorisation of scientific cultural heritage. The role of the Italian University Museums network

The framework program about multimedia technologies for the networking and the valorization of scientific cultural heritage in the Italian University Museums among thirteen Italian Universities (Bari, Cagliari, Chieti-Pescara, Ferrara, Florence, Modena and Reggio Emilia, Parma, Perugia, Rome “La Sapienza”, Salento, Naple II, Siena, Tuscia), with the coordination of the University of Modena, has been recently approved and financed by the Italian Ministry of Education, University and Research. It aims at activating a network that by multimedia technologies wish contribute to knowledge and valorization of cultural heritage through the collaboration of UMAC University Museums and Collections International Committee of ICOM. The final target will be a bilingual web portal realized, on purpose for the project, in an innovative perspective considering the peculiar features of the different University Museums collections, the experience of each, their interdisciplinary characterization and the possible uses in a contemporary historical, social and cultural context. The first step is to monitor the cultural heritage of the thirteen University Museums, in order to complete the already existing databases and align them to catalogue standards released by the Central Institute for Cataloguing and Documentation of the Italian Ministry of the Culture within the General Informative System for Cataloguing SIGECWeb

Graphical Encoding of a Spatial Logic for the pi-Calculus

This paper extends our graph-based approach to the verification of spatial properties of π-calculus specifications. The mechanism is based on an encoding for mobile calculi where each process is mapped into a graph (with interfaces) such that the denotation is fully abstract with respect to the usual structural congruence, i.e., two processes are equivalent exactly when the corresponding encodings yield isomorphic graphs. Behavioral and structural properties of π-calculus processes expressed in a spatial logic can then be verified on the graphical encoding of a process rather than on its textual representation. In this paper we introduce a modal logic for graphs and define a translation of spatial formulae such that a process verifies a spatial formula exactly when its graphical representation verifies the translated modal graph formula

Retiolites angustidens Elles & Wood, 1908 (Graptholitina) from the Silurian of Mt. Cocco (Carnic Alps, Italy)

Retiolites angustidens, trovato in un blocco isolato di calcare a Orthoceras nell’area di Monte Cocco in associazione con Monograptus cf. priodon, viene qui descritto e figugurato per la prima volta nelle Alpi Carniche: in precedenza la sua presenza, infatti, era stata segnalata, ma mai documentata. Dato che tutti i graptoliti rinvenuti hanno un limitato valore stratigrafico, l’età precisa dell’associazione studiata è attribuita alla Biozona a Pterospathodus am. amorphognathoides (Llandovery sup.) in base ai conodonti.Retiolites angustidens is described and figured for the first time from the Carnic Alps, from a loose block collected from Mt. Cocco area. ! e association includes also Monograptus cf. priodon: this species, in fact, was previously reported, but never documented, from this area. Since all the graptolites found have a limited stratigraphic value, the precise age of the studied association is determined by conodonts as belonging to the latest Llandovery (Pterospathodus am. amorphognathoides conodont Zone)

Blown-up p-Branes and the Cosmological Constant

We consider a blown-up 3-brane, with the resulting geometry R^(3,1) \times S^(N-1), in an infinite-volume bulk with N > 2 extra dimensions. The action on the brane includes both an Einstein term and a cosmological constant. Similar setups have been proposed both to reproduce 4-d gravity on the brane, and to solve the cosmological constant problem. Here we obtain a singularity-free solution to Einstein's equations everywhere in the bulk and on the brane, which allows us to address these question explicitely. One finds, however, that the proper volume of S^(N-1) and the cosmological constant on the brane have to be fine-tuned relatively to each other, thus the cosmological constant problem is not solved. Moreover the scalar propagator on the brane behaves 4-dimensionally over a phenomenologically acceptable range only if the warp factor on the brane is huge, which aggravates the Weak Scale - Planck Scale hierarchy problem.Comment: 21 pages, no figure

Urban Scale Monitoring Approach for the Assessment of Rising Damp Effects in Venice

In coastal areas, the rising damp of salty water is a well-known degradation factor of historical masonries, leading to visible features such as crusts, masonry erosion, and plaster loss. Venetian masonries are strongly affected by decay caused by rising damp exacerbated by direct contact with salty water. Recurrent flooding due to high tides and an increase in the frequency of flooding events, also related to climate change, raises concern about the impacts. Although several studies have been carried out on probable future scenarios, a valuation of the decay risk due to rising damp at the urban level still needs to be implemented. This paper proposes a non-invasive and economically sustainable approach for evaluating rising damp effects at an urban scale. The approach includes a collection of archive images of masonries affected by rising damp dating back to the 1990s; a visual survey of the actual conservation state of masonries; a classification based on significant descriptors; and a discussion on exposure conditions and conservation states. The descriptors chosen are rising damp levels, biological growth, plaster loss, efflorescence, and brick erosion. The evaluation was implemented in a georeferenced system suitable for future comparisons, thus providing a management tool for the city's preservation

Model driven design and implementation of activity-based applications in Hermes

Hermes is an agent-based middleware structured as a component-based and 3-layered software architecture. Hermes provides an integrated, exible programming environment for design and execution of activity-based applications in distributed environments. By using workow technology, it supports even a non expert user programmer in the model driven design and implementation of a domain specic application. In this paper, after a description of Hermes software architecture, we provide a simple demo in biological domain and we show some real case studies in which Hermes has been validated