Irreversible decay of nonlocal entanglement via a reservoir of a single degree of freedom

Recently, it has been realized that nonlocal disentanglement may take a finite time as opposite to the asymptotic decay of local coherences. We find in this paper that a sudden irreversible death of entanglement takes place in a two atom optical Stern-Gerlach model. In particular, the one degree non dissipative environment here considered suddenly destroys the initial entanglement of any Bell's states $\ket{\phi^{\pm}}$ superposition.Comment: 6 pages, 4 figures, improved presentation, v2: title changed, references added, accepted for publication in Phys. Rev. A (Fundamental concepts

Translational dynamics effects on the non-local correlations between two atoms

A pair of atoms interacting successively with the field of the same cavity and exchanging a single photon, leave the cavity in an entangled state of Einstein-Podolsky-Rosen (EPR) type (see, for example, [S.J.D. Phoenix, and S.M. Barnett, J. Mod. Opt. \textbf{40} (1993) 979]). By implementing the model with the translational degrees of freedom, we show in this letter that the entanglement with the translational atomic variables can lead, under appropriate conditions, towards the separability of the internal variables of the two atoms. This implies that the translational dynamics can lead, in some cases, to difficulties in observing the Bell's inequality violation for massive particles.Comment: 5 pages, 1 figur

On the observability of Bell's inequality violation in the optical Stern-Gerlach model

Using the optical Stern-Gerlach model, we have recently shown that the non-local correlations between the internal variables of two atoms that successively interact with the field of an ideal cavity in proximity of a nodal region are affected by the atomic translational dynamics. As a consequence, there can be some difficulties in observing violation of the Bell's inequality for the atomic internal variables. These difficulties persist even if the atoms travel an antinodal region, except when the spatial wave packets are exactly centered in an antinodal point.Comment: 5 pages, 1 figure, submitted to European Physical Journal

Statistical identification with hidden Markov models of large order splitting strategies in an equity market

Large trades in a financial market are usually split into smaller parts and traded incrementally over extended periods of time. We address these large trades as hidden orders. In order to identify and characterize hidden orders we fit hidden Markov models to the time series of the sign of the tick by tick inventory variation of market members of the Spanish Stock Exchange. Our methodology probabilistically detects trading sequences, which are characterized by a net majority of buy or sell transactions. We interpret these patches of sequential buying or selling transactions as proxies of the traded hidden orders. We find that the time, volume and number of transactions size distributions of these patches are fat tailed. Long patches are characterized by a high fraction of market orders and a low participation rate, while short patches have a large fraction of limit orders and a high participation rate. We observe the existence of a buy-sell asymmetry in the number, average length, average fraction of market orders and average participation rate of the detected patches. The detected asymmetry is clearly depending on the local market trend. We also compare the hidden Markov models patches with those obtained with the segmentation method used in Vaglica {\it et al.} (2008) and we conclude that the former ones can be interpreted as a partition of the latter ones.Comment: 26 pages, 12 figure

Application of Carbon Nanotube Thermophones as Duct Noise Cancelling Speakers: Using New Technology with Old Theories

Certain materials can produce sound through heat fluctuations. In recent times, the material capable of this was discovered to be Carbon Nanotubes (CNT). The idea is to create a flexible speaker that can be made into any shape or form to create sound. Once a speaker has been created, an active noise control system can be designed to cancel loud sounds in building and pipe ducts. This technology, similar to noise cancelling headphones, allows a user to create a modular system to mitigate noise in everyday life. Thus, the purpose of this research is to illustrate the abilities of a CNT speaker system to perform active noise control on an HVAC duct application. This paper will start with a brief introduction into CNT technology and thermophone acoustics before diverging into active noise control technology. It will illustrate planar and non –planar wave cancellation and showcase a small scale accelerated life test

Trading activity and price impact in parallel markets: SETS vs. off-book market at the London Stock Exchange

We empirically study the trading activity in the electronic on-book segment and in the dealership off-book segment of the London Stock Exchange, investigating separately the trading of active market members and of other market participants which are non-members. We find that (i) the volume distribution of off-book transactions has a significantly fatter tail than the one of on-book transactions, (ii) groups of members and non-members can be classified in categories according to their trading profile (iii) there is a strong anticorrelation between the daily inventory variation of a market member due to the on-book market transactions and inventory variation due to the off-book market transactions with non-members, and (iv) the autocorrelation of the sign of the orders of non-members in the off-book market is slowly decaying. We also analyze the on-book price impact function over time, both for positive and negative lags, of the electronic trades and of the off-book trades. The unconditional impact curves are very different for the electronic trades and the off-book trades. Moreover there is a small dependence of impact on the volume for the on-book electronic trades, while the shape and magnitude of impact function of off-book transactions strongly depend on volume.Comment: 16 pages, 9 figure

The non dissipative damping of the Rabi oscillations as a "which-path" information

Rabi oscillations may be viewed as an interference phenomenon due to a coherent superposition of different quantum paths, like in the Young's two-slit experiment. The inclusion of the atomic external variables causes a non dissipative damping of the Rabi oscillations. More generally, the atomic translational dynamics induces damping in the correlation functions which describe non classical behaviors of the field and internal atomic variables, leading to the separability of these two subsystems. We discuss on the possibility of interpreting this intrinsic decoherence as a "which-way" information effect and we apply to this case a quantitative analysis of the complementarity relation as introduced by Englert [Phys. Rev. Lett. \textbf{77}, 2154 (1996)].Comment: 5 pages, 2 figure

The abbot Bonifacio Maria Krug on the Gospel notes

La vita di Gesù - pensieri musicali è il nome che attribuì Bonifacio Maria Krug alla raccolta di 6 composizioni pianistiche ispirate ad altrettanti episodi del Vangelo. L’abate compose i sei brani per pianoforte ispirandosi ad una sacralità totalizzante e coerente al movimento ceciliano che tra la fine del 1800 e la prima metà del 1900 esaltava il ritorno alle origini della musica liturgica pura. Ogni brano è numerato da 1 a 6 e presenta un titolo e un sottotitolo con riferimenti precisi: il titolo cita un luogo (eccetto l’ultimo Alleluia), il sottotitolo la descrizione concisa dell’episodio biblico narrato musicalmente. È come se si volesse compiere un viaggio spirituale calandosi nella realtà di quei luoghi dalla forte connotazione simbolica. Nazareth, Bethlem, Genesareth, Gethsemani e Golgotha scandiscono idealmente le tappe del percorso esistenziale di Cristo sulla Terra, per terminare con l’alleluia, inno d’esultanza per la risurrezione dell’Uomo-Dio. La ricerca proposta intende fornire un’analisi armonico-formale delle 6 opere sacre per pianoforte composte da Bonifacio Maria Krug, esaminando le scelte formali e tecniche dell’abate benedettino e le sue implicazioni simboliche legate alle Sacre Scritture. L’argomentazione è supportata da frammenti esemplificativi degli spartiti che delineano il profilo creativo musicale dell’Abate- compositore.La vita di Gesù- pensieri musicali is the name Bonifacio Maria Krug gave to the collection of 6 piano compositions inspired to the likewise Gospel episodes. The abbot composed these 6 piano pieces with a complete sacredness coherent with the Cecilian movement which exalted the return of pure liturgical music between the end of 1800 and the first half of 1900. Each piece is numbered from 1 to 6 and has a title and a subtitle. The title indicates a specific place (except the last one, Alleluia); the subtitle describes the Gospel episode the music tells. It is a sort of spiritual journey in the reality of those sacred places. Nazareth, Bethlehem, Genesareth, Gethsemani and Golgotha are ideally the steps of the existential route of Jesus Christ on Earth ending with Alleluia which celebrates the resurrection. This research offers a formal-harmonic analysis of these 6 piano works composed by Bonifacio Maria Krug, examining formal and technical musical choices and symbolic implications related to the Holy Scriptures. This argumentation is supported by some sections of the piano scores which underline the creative profile of the composer-abbot

La trasfusione nel cane: valutazione retrospettiva di alcuni parametri clinico-patologici

Parole chiave: trasfusione, cane, ematocrito, ematocrito post-trasfusione, PRBC, SWB Background: la medicina trasfusionale nel cane si è molto diffusa negli ultimi anni, come pratica terapeutica e salvavita. È stato eseguito uno studio retrospettivo (gennaio 2010- marzo 2016) presso l’Ospedale Didattico Veterinario “Mario Modenato”, Università di Pisa. Animali: attraverso l’analisi delle cartelle cliniche di 108 soggetti trasfusi con concentrato di RBC o sangue intero conservato, sono state prese in considerazione le alterazioni cliniche e clinico-patologiche di 85 soggetti che presentavano anemia. Obiettivi: determinare i principali motivi di trasfusione e dopo aver valutato e classificato le cause di anemia dei riceventi, analizzare l’incremento di ematocrito dopo la trasfusione in relazione alla gravità e decorso dell’anemia e alle caratteristiche del prodotto trasfuso; analizzare i parametri vitali in corso di trasfusione: frequenza cardiaca (FC), frequenza respiratoria (FR) e temperatura. Materiali e metodi: l’anemia dei riceventi è stata classificata in base a Hct, MCV e MCHC; l’incremento di Hct nel ricevente a T1, T2, T3, T4 e T5 è stato correlato statisticamente all’Hct pre-trasfusione; i riceventi sono stati divisi in 3 gruppi in base alla gravità dell’anemia (gravissima, grave e moderata) e per ogni gruppo si è calcolato l’andamento temporale dell’ Hct e si sono confrontati gli incrementi di Hct tra i gruppi; l’incremento di Hct nei riceventi a T1, T2, T3 e T4 è stato correlato statisticamente al volume trasfuso (ml/kg) e all’età della sacca. È stato analizzato l’andamento temporale e l’incremento di Hct in base alla causa di anemia; sono stati analizzati i valori di FC, FR e temperatura durante la trasfusione a T0 (inizio trasfusione), T1(dopo 15 minuti), T2 (a metà trasfusione) e T3 (a ¾ della trasfusione). Risultati e conclusioni: il principale motivo di trasfusione di RBC è stata una perdita eritrocitaria acuta (53%), causata soprattutto da emorragia (36%); l’anemia era nella maggior parte dei casi gravissima (55%) o grave (35%) e quasi sempre con rigenerazione lieve o assente (87,5%). I cani con anemia più grave hanno avuto un maggior incremento di Hct a T1 e T3; l’incremento di Hct a T3 e T4 era inversamente proporzionale all’età della sacca. I valori di FC e FR sono diminuiti durante la trasfusione; abbiamo trovato una differenza significativa tra i valori di FC a T0 e T1 e quelli a T3 e T4. Tra i soggetti trasfusi più di una volta, la maggior parte avevano anemia da perdita eritrocitaria acuta

Scaling laws of strategic behaviour and size heterogeneity in agent dynamics

The dynamics of many socioeconomic systems is determined by the decision making process of agents. The decision process depends on agent's characteristics, such as preferences, risk aversion, behavioral biases, etc.. In addition, in some systems the size of agents can be highly heterogeneous leading to very different impacts of agents on the system dynamics. The large size of some agents poses challenging problems to agents who want to control their impact, either by forcing the system in a given direction or by hiding their intentionality. Here we consider the financial market as a model system, and we study empirically how agents strategically adjust the properties of large orders in order to meet their preference and minimize their impact. We quantify this strategic behavior by detecting scaling relations of allometric nature between the variables characterizing the trading activity of different institutions. We observe power law distributions in the investment time horizon, in the number of transactions needed to execute a large order and in the traded value exchanged by large institutions and we show that heterogeneity of agents is a key ingredient for the emergence of some aggregate properties characterizing this complex system.Comment: 6 pages, 3 figure