Signatures of Quantum Gravity in a Born-Oppenheimer Context

We solve a general equation describing the lowest order corrections arising from quantum gravitational effects to the spectrum of cosmological fluctuations. The spectra of scalar and tensor perturbations are calculated to first order in the slow roll approximation and the results are compared with the most recent observations. The slow roll approximation gives qualitatively new quantum gravitational effects with respect to the pure de Sitter case.Comment: 19 pages, 2 figures; final version accepted for publication in PL

Quantum Gravity and the Large Scale Anomaly

The spectrum of primordial perturbations obtained by calculating the quantum gravitational corrections to the dynamics of scalar perturbations is compared with Planck 2013 and BICEP2/{\it Keck Array} public data. The quantum gravitational effects are calculated in the context of a Wheeler-De Witt approach and have quite distinctive features. We constrain the free parameters of the theory by comparison with observations.Comment: 17 pages, 3 figures; the analysis has been updated with the combined Planck-BICEP2/Keck Array public data. Final version, accepted for publication in JCA

Inflation and Quantum Gravity in a Born-Oppenheimer Context

A general equation, describing the lowest order corrections coming from quantum gravitational effects to the spectrum of cosmological scalar fluctuations is obtained. These corrections are explicitly estimated for the case of a de Sitter evolution.Comment: 13 pages, no figures. Final version, accepted for publication in PL

Linked open graph: Browsing multiple SPARQL entry points to build your own LOD views

AbstractA number of accessible RDF stores are populating the linked open data world. The navigation on data reticular relationships is becoming every day more relevant. Several knowledge base present relevant links to common vocabularies while many others are going to be discovered increasing the reasoning capabilities of our knowledge base applications. In this paper, the Linked Open Graph, LOG, is presented. It is a web tool for collaborative browsing and navigation on multiple SPARQL entry points. The paper presented an overview of major problems to be addressed, a comparison with the state of the arts tools, and some details about the LOG graph computation to cope with high complexity of large Linked Open Dada graphs. The LOG.disit.org tool is also presented by means of a set of examples involving multiple RDF stores and putting in evidence the new provided features and advantages using dbPedia, Getty, Europeana, Geonames, etc. The LOG tool is free to be used, and it has been adopted, developed and/or improved in multiple projects: such as ECLAP for social media cultural heritage, Sii-Mobility for smart city, and ICARO for cloud ontology analysis, OSIM for competence/knowledge mining and analysis

Reflected waves and quantum gravity

In the context of canonical quantum gravity, we consider the effects of a nonstandard expression for the gravitational wave function on the evolution of inflationary perturbations. Such an expression and its effects may be generated by a sudden variation in the (nearly constant) inflaton potential. The resulting primordial spectra, up to the leading order, are affected in the short and in the long wavelength regime, where an oscillatory behavior with a non-negligible amplitude is superimposed on the standard semiclassical result. Moreover, a novel, nonperturbative, approach is used to study the evolution. Finally, a simplified application is fully illustrated and commented

Pulmonary embolism: yet another cause of hypoxaemic respiratory failure in COVID-19

Pulmonary embolism represents an overlooked cause of worsening respiratory failure in COVID-19. A regular bedside evaluation for atypical features like pleuritic chest pain or pleural effusion could help identify suspected cases for appropriate management

Reconstruction methods and the amplification of the inflationary spectrum

We analyze the consequences of different evolutions of the Hubble parameter on the spectrum of scalar inflationary perturbations. The analysis is restricted to inflationary phases described by a transient evolution, when uncommon features arise in the inflationary spectra that may lead to an amplitude enhancement. We then discuss how the spectrum is, respectively, amplified or blue-tilted in the presence or absence of a growing solution of the Mukhanov-Sasaki equation. The cases of general relativity with a minimally coupled inflaton and that of induced gravity are considered explicitly. Finally, some remarks on constant roll inflation are discussed.Comment: references updated, conceptual clarifications added. Matches published versio