Spin-Particles Entanglement in Robertson-Walker Spacetime

We study the entanglement between two modes of Dirac field in an expanding spacetime characterized by the Robertson-Walker metric. This spacetime model turns out to be asymptotically (in the remote past and far future regions) Minkowskian. Then, on the one hand we show entanglement creation between particles and anti-particles when passing from remote past to far future. On the other hand we show that particles entanglement in the remote past degrades into the far future. These effects are traced back to particles creation. In our analysis we highlight the role of spin (polarization) of particles and compare the results with those obtainable without accounting for it

Preserving Information from the Beginning to the End of time in a Robertson-Walker Spacetime

Preserving information stored in a physical system subjected to noise can be modeled in a communication-theoretic paradigm, in which storage and retrieval correspond to an input encoding and output decoding, respectively. The encoding and decoding are then constructed in such a way as to protect against the action of a given noisy quantum channel. This paper considers the situation in which the noise is not due to technological imperfections, but rather to the physical laws governing the evolution of the universe. In particular, we consider the dynamics of quantum systems under a 1+1 Robertson-Walker spacetime and find that the noise imparted to them is equivalent to the well known amplitude damping channel. Since one might be interested in preserving both classical and quantum information in such a scenario, we study trade-off coding strategies and determine a region of achievable rates for the preservation of both kinds of information. For applications beyond the physical setting studied here, we also determine a trade-off between achievable rates of classical and quantum information preservation when entanglement assistance is available.Comment: 19 pages, 3 figures. Presentation updated, matches the published versio

Shawbak Castle in Jordan and its environment: conservation and evaluation

L'intervento ha illustrato il tema del restauro e della valorizzazione del castello di Shawbak in Giordania e del territorio circostante. Sono stati esposti i seguenti risultati della ricerca delle campagne di lavoro in Giordania nel 2011 e 2012: -i progetti di restauro della chiesa di S.Maria, palazzo Jubbide, bastione sud-ovest; -il master plan di valorizzazione del castello e degli insediamenti antichi circostanti; -l'ideazione di un progetto di musealizzazione del castello; -il progetto di massima dei percorsi di visit

Entanglement in anisotropic expanding spacetime

We study the effect of space anisotropy in the entanglement generated by expanding universe on spin 0 and 1/2 fields. For massive scalar field we find revivals of entanglement entropy vs momentum after decreasing from the maximum at k = 0. In massive Dirac field the effect is a slight distortion of the non-monotonic profile giving rise to the maximum of entanglement entropy at k > 0. More interestingly, massless field of both type can only get entangled through anisotropy, with a maximum of entanglement entropy occurring at k > 0

3-(Phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole: a fascinating molecular framework to study the enantioseparation ability of the amylose (3,5-dimethylphenylcarbamate) chiral stationary phase. Part I. Structure-enantioselectivity relationships

Chiral stationary phases (CSPs) based on amylose (3,5-dimethylphenylcarbamate) (ADMPC) exhibit awide-range of enantioselectivity in high-performance liquid chromatography (HPLC) and supercriticalfluid chromatography (SFC). Although this class of CSPs has been extensively used, chiral discriminationsat receptorial level, which are useful to develop predictive molecular models, have been rarely reportedin the literature.Herein, we describe the results obtained in the enantioselective HPLC of a set of six C5-chiral 4,5-dihydro-(1H)-pyrazole derivatives on the ADMPC-based Chiralpak AD-3 CSP (CSP) under normal-phaseand polar organic conditions. Using pure methanol as a mobile phase the exceptional enantioseparationfactor value of 50 at 25◦C was found for one of the investigated analytes. To the best of our knowledge, theenantiomeric bias represents the most outstanding enantioseparation ever recorded on ADMPC-basedCSPs.Systematic variations in chemical groups in specific positions of the 3-(phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole molecular framework resulted in peculiar changes in retention andenantioselectivity. A careful analysis of the chromatographic data permitted to advance some hypothesesconcerning the role played by the individual chemical groups in determining the exceptional enantiosep-aration.In particular, under methanol-rich mode, the prenyl moiety of the second eluted enantiomer of thebetter resolved analyte was recognized as a critical structural element to establish direct and favorablesolvophobic interactions with apolar portions of selector

TetraPh-Tol-BITIOPO: a new atropisomeric 3,3’-bithiophene based phosphine oxide as organocatalyst in Lewis Base-catalyzed Lewis Acid mediated reactions

A new chiral phosphine oxide based on 3,3’-bithiophene scaffold (tetraPh-Tol-BITIOPO) was synthesized, fully characterized and separated into antipodes through chiral HPLC. This new compound was successfully employed as organocatalyst in Lewis base-catalyzed Lewis acid mediated reactions involving trichlorosilyl compounds. The new atropisomeric catalyst was able to promote the allylation of aldehydes with allyltrichlorosilane in up to 98% yield and up to 96% enantiomeric excess (ee), and the direct aldol reaction to afford β-hydroxy ketones and β-hydroxy thioesters, with good chemical yields and modest stereochemical efficiency. Computational studies helped to elucidate and to rationalize the stereochemical outcome of the reactions catalyzed by TetraPh-Tol-BITIOPO, that was found to favour the formation of the isomer with the opposite absolute configuration in comparison with the products obtained with the previously reported 3,3’-bithiophene-based catalyst

The Triangular Fortress of Butrint, Albania. New studies for the conservation and the valorisation

[EN] An important programme of valorisation of the architectural heritage involved the Triangular Fortress in Butrint, in Albania, nowadays UNESCO World Heritage Site. The little knowledge on this supposedly 15th-century Venetian fortress represented a stimulating task for a research, which started with the architectural survey of the structure. Finding information on the time of construction was challenging, the few written books and essays being hardly compatible and lacking confirmation. Therefore, a research was carried out in the State Archives and the Museo Correr Library in Venice, which unveiled unpublished manuscripts and drawings, casting new light on the fortress. On the base of this study, it is now possible to suppose that the Ottomans erected the fortress after 1655. The archive founds, together with the results of the survey analysis, helped also to depict a plausible sequence of the historical phases of construction until its damaging in 1798.Bevilacqua, MG.; Pierini, R.; Pierotti, M.; Ruschi, P. (2015). The Triangular Fortress of Butrint, Albania. New studies for the conservation and the valorisation. En Defensive architecture of the mediterranean: XV to XVIII centuries. Vol. I. Editorial Universitat Politècnica de València. 33-40. https://doi.org/10.4995/FORTMED2015.2015.1720334

An rf-linac, FEL buncher

Abstract We describe a means of producing a train of 40 kA pulses of 3 ps duration as the drive beam for CLIC using an rf linac driven free electron laser (FEL) buncher. Potential debunching effects are discussed. Finally we describe a low energy test experiment