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Radio transient discovery using next generation radio telescopes will pose several digital signal processing and data transfer challenges, requiring specialized high-performance backends. Several accelerator technologies are being considered as prototyping platforms, including Graphics Processing Units (GPUs). In this paper we present a real-time pipeline prototype capable of processing multiple beams concurrently, performing Radio Frequency Interference (RFI) rejection through thresholding, correcting for the delay in signal arrival times across the frequency band using brute-force dedispersion, event detection and clustering, and finally candidate filtering, with the capability of persisting data buffers containing interesting signals to disk. This setup was deployed at the BEST-2 SKA pathfinder in Medicina, Italy, where several benchmarks and test observations of astrophysical transients were conducted. These tests show that on the deployed hardware eight 20MHz beams can be processed simultaneously for $\sim$640 Dispersion Measure (DM) values. Furthermore, the clustering and candidate filtering algorithms employed prove to be good candidates for online event detection techniques
The purpose of this paper is to prove directly, by an elementary method, the Poisson probability law. This proof is offered as an alternative to the more usual derivation from binomial distribution in the limit of small probabilities. The same proof is then applied to the solution of a problem in statistical mechanics. --- Lo scopo di questo articolo è dimostrare direttamente, con un metodo elementare, la legge di probabilità di Poisson. Questa dimostrazione è proposta in alternativa alla più consueta derivazione dalla distribuzione binomiale nel limite delle piccole probabilità. La stessa dimostrazione viene quindi applicata alla soluzione di un problema di meccanica statistica.
In the present work it is evaluated the evolutionary state of the Orion Belt stars, an asterism very important for the ancient Egyptians, finding that, when the pyramids were built, the brightness of the three stars of the Belt was practically the same as today. This not trivial result has important implications in the framework of the so-called Orion Correlation Theory, a controversial theory proposed by Bauval and Gilbert (1994), according to which a perfect coincidence would exist between the disposition of the three stars of the Orion Belt and that of the main Giza pyramids, so that the latter would represent the monumental reproduction on the ground of that important asterism. ---- Nel presente lavoro viene determinato lo stato evolutivo delle stelle della Cintura di Orione, ricavando che, all'epoca della costruzione delle piramidi, la luminosita' delle tre stelle della Cintura era di fatto uguale a quella odierna. Tale non banale risultato riveste una importanza fondamentale nell'ambito della verifica della controversa Teoria della Correlazione di Orione proposta da Bauval e Gilbert nel 1994, secondo la quale esisterebbe una perfetta coincidenza tra la disposizione delle tre
The Simultaneous Medicina-{\it Planck} Experiment (SiMPlE) is aimed at observing a selected sample of 263 extragalactic and Galactic sources with the Medicina 32-m single dish radio telescope in the same epoch as the Planck satellite observations. The data acquired with a frequency coverage down to 5 GHz, also combined with Planck at frequencies above 30 GHz, will constitute a useful reference catalogue of bright sources over the whole Northern hemisphere. Furthermore, source observations performed in different epochs and comparison with other catalogues allow the investigation of source variabilities on different timescales. In this work, we describe the sample selection, the on-going data acquisition campaign, the data reduction procedures, the developed tools, and the comparison with other data-sets. We present the data at 5 and 8.3 GHz for the SiMPlE Northern Sample consisting of 79 sources with $δ\geq 45^\circ$ selected in our catalogue and observed during the first 6 months of the project. A first analysis of their spectral behaviour and long-term variability is also presented.
Procedural Content Generation (PCG) is powerful in creating high-quality 3D contents, yet controlling it to produce desired shapes is difficult and often requires extensive parameter tuning. Inverse Procedural Content Generation aims to automatically find the best parameters under the input condition. However, existing sampling-based and neural network-based methods still suffer from numerous sample iterations or limited controllability. In this work, we present DI-PCG, a novel and efficient method for Inverse PCG from general image conditions. At its core is a lightweight diffusion transformer model, where PCG parameters are directly treated as the denoising target and the observed images as conditions to control parameter generation. DI-PCG is efficient and effective. With only 7.6M network parameters and 30 GPU hours to train, it demonstrates superior performance in recovering parameters accurately, and generalizing well to in-the-wild images. Quantitative and qualitative experiment results validate the effectiveness of DI-PCG in inverse PCG and image-to-3D generation tasks. DI-PCG offers a promising approach for efficient inverse PCG and represents a valuable exploration step t
At the INFN laboratory in Pisa I have prepared my dissertation, which essentially concerned Montecarlo simulation of subnuclear particles decays and investigation of low-noise electronic devices for analyzing high-frequency signals. The team-work was part of NA48/EPSI experiment jointly carried out with European Organization for Nuclear Research CERN, Geneva. ----- Nell'ambito dell'esperimento NA48 in corso al CERN Super Proton Syncrothon (SPS) finalizzato a misurare la violazione diretta di CP in sistemi di particelle K0 attraverso il doppio rapporto R = [N(K_L->Pi0Pi0)]/[N(K_S->Pi0Pi0)] / [N(K_L->Pi+Pi-)]/[N(K_S->Pi+Pi-)] = 1 - 6 Re(e1/e) con una precisione di Re(e1/e) superiore a 2 * 10^-4, il lavoro di tesi si propone di effettuare una simulazione per la rivelazione dei decadimenti neutri dei K0 ed una successiva analisi dei dati raffrontando l'evento fisico generato con metodo Montecarlo e quello ricostruito. Per la misura di e1/e occorre isolare tra i vari modi di decadimento dei K quelli K_S->Pi0Pi0, K_S->Pi+Pi-, e quelli K_L->Pi0Pi0, K_L->Pi+Pi-.
La teoria di Lagrange per i moti secolari delle eccentricità ed inclinazioni delle orbite planetarie si fondava su un'approssimazione, dettata in larga misura dalla complessità dei calcoli necessari, che consisteva nel considerare solo equazioni lineari. In questa memoria riprendiamo in considerazione i metodi di Lagrange alla luce della teoria della stabilità esponenziale di Nekhoroshev. Grazie agli algoritmi sviluppati negli ultimi anni e alle tecniche di manipolazione algebrica possiamo tener conto anche dei contributi non lineari alle equazioni. Come applicazione cerchiamo di determinare i tempi di stabilità per il problema dei tre corpi nel caso del Sole e dei due pianeti maggiori, Giove e Saturno, mostrando che si possono ottenere risultati realistici, ancorché non ottimali. Lagrange's theory for the secular motion of perihelia and nodes of the planetary orbits was based on consideration of a linear approssimation of the dynamical equations, compatible with the complexity of the calculations. We extend Lagrange's investigations in the light of Nekhoroshev's theory of exponential stability. Using effective algorithms recently developed and computer algebra we investigate the n
In the article, we will report on the recovery of a Melloni's optical bench built at the end of 1800 by the "macchinista" Filippo Caliri in the "belle époque" of Palermo. A scientific instrument of particular historical and didactic interest belonging to the collection of Liceo Classico Statale "Umberto I" of Palermo. In the article, we will discuss the technical aspects of the interventions carried out. In questo articolo discuteremo del recupero di uno strumento scientifico di particolare interesse storico-didattico appartenente alla Collezione del Liceo Classico Statale "Umberto I" di Palermo: un raro banco ottico del Melloni costruito alla fine del 1800 nella Palermo della "belle époque" dal "macchinista" Filippo Caliri. Nell'articolo discuteremo gli aspetti tecnici degli interventi conservativi effettuati.
This document summarises the current theoretical and experimental status of the di-Higgs boson production searches, and of the direct and indirect constraints on the Higgs boson self-coupling, with the wish to serve as a useful guide for the next years. The document discusses the theoretical status, including state-of-the-art predictions for di-Higgs cross sections, developments on the effective field theory approach, and studies on specific new physics scenarios that can show up in the di-Higgs final state. The status of di-Higgs searches and the direct and indirect constraints on the Higgs self-coupling at the LHC are presented, with an overview of the relevant experimental techniques, and covering all the variety of relevant signatures. Finally, the capabilities of future colliders in determining the Higgs self-coupling are addressed, comparing the projected precision that can be obtained in such facilities. The work has started as the proceedings of the Di-Higgs workshop at Colliders, held at Fermilab from the 4th to the 9th of September 2018, but it went beyond the topics discussed at that workshop and included further developments.
The STAR collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au+Au and minimum-bias d+Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au+Au data with respect to the d+Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the \emph{ridge region}, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.
We present a search for long-lived particles (LLPs) produced from kaon decay that decay to two muons inside the ICARUS neutrino detector. This channel would be a signal of hidden sector models that can address outstanding issues in particle physics such as the strong CP problem and the microphysical origin of dark matter. The search is performed with data collected in the Neutrinos at the Main Injector (NuMI) beam at Fermilab corresponding to $2.41\times 10^{20}$ protons-on-target. No new physics signal is observed, and we set world-leading limits on heavy QCD axions, as well as for the Higgs portal scalar among dedicated searches. Limits are also presented in a model-independent way applicable to any new physics model predicting the process $K\to π+S(\toμμ)$, for a long-lived particle S. This result is the first search for new physics performed with the ICARUS detector at Fermilab. It paves the way for the future program of long-lived particle searches at ICARUS.
We characterize type isomorphisms in the multiplicative-additive fragment of linear logic (MALL), and thus in *-autonomous categories with finite products, extending a result for the multiplicative fragment by Balat and Di Cosmo. This yields a much richer equational theory involving distributivity and cancellation laws. The unit-free case is obtained by relying on the proof-net syntax introduced by Hughes and Van Glabbeek. We use the sequent calculus to extend our results to full MALL, including all units, thanks to a study of cut-elimination and rule commutations.
We search for gravitational-wave transients associated with fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB), during the first part of the third observing run of Advanced LIGO and Advanced Virgo (1 April 2019 15:00 UTC-1 Oct 2019 15:00 UTC). Triggers from 22 FRBs were analyzed with a search that targets compact binary coalescences with at least one neutron star component. A targeted search for generic gravitational-wave transients was conducted on 40 FRBs. We find no significant evidence for a gravitational-wave association in either search. Given the large uncertainties in the distances of the FRBs inferred from the dispersion measures in our sample, however, this does not conclusively exclude any progenitor models that include emission of a gravitational wave of the types searched for from any of these FRB events. We report $90\%$ confidence lower bounds on the distance to each FRB for a range of gravitational-wave progenitor models. By combining the inferred maximum distance information for each FRB with the sensitivity of the gravitational-wave searches, we set upper limits on the energy emitted through
One of the proposals for the exploitation of two-dimensional quantum walks has been the efficient generation of entanglement. Unfortunately, the technological effort required for the experimental realization of standard two-dimensional quantum walks is significantly demanding. In this respect, an alternative scheme with less challenging conditions has been recently studied, particularly in terms of spatial-entanglement generation [C. Di Franco, M. Mc Gettrick, and Th. Busch, Phys. Rev. Lett. 106, 080502 (2011)]. Here, we extend the investigation to a scenario where a measurement is performed on the coin degree of freedom after the evolution, allowing a further comparison with the standard two-dimensional Grover walk.
We scrutinise the evidences recently reported by the ATLAS and CMS collaborations for compatible 750 GeV resonances which appear in the di-photon channels of the two experiments in both the 8 TeV and 13 TeV datasets. Similar resonances in di-boson, di-lepton, di-jet and $t\bar t$ final states are instead not detected. After discussing the properties and the compatibility of the reported signals, we study the implications on the physics beyond the Standard Model with particular emphasis on possible scalar extensions of the theory such as singlet extensions and the two Higgs doublet models. We also analyse the significance of the new experimental indications within the frameworks of the minimal supersymmetric standard model and of technicolour models. Our results show that a simple effective singlet extension of the SM achieves phenomenological viability with a minimal number of free parameters. The minimal supersymmetric model and the two Higgs doublet model, on the other hand, cannot explain the 750 GeV di-photon excess. Compatibility with the observed signal requires the extension of the particle content of these models, for instance by heavy vector quarks in the case of the two H
The inclusive cross sections for di-hadrons of charged pions and kaons ($e^+e^- \rightarrow hhX$) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere di-hadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a $655\,{\rm fb}^{-1}$ data sample collected at or near the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.
We have recently proposed a two-dimensional quantum walk where the requirement of a higher dimensionality of the coin space is substituted with the alternance of the directions in which the walker can move [C. Di Franco, M. Mc Gettrick, and Th. Busch, Phys. Rev. Lett. {\bf 106}, 080502 (2011)]. For a particular initial state of the coin, this walk is able to perfectly reproduce the spatial probability distribution of the non-localized case of the Grover walk. Here, we present a more detailed proof of this equivalence. We also extend the analysis to other initial states, in order to provide a more complete picture of our walk. We show that this scheme outperforms the Grover walk in the generation of $x$-$y$ spatial entanglement for any initial condition, with the maximum entanglement obtained in the case of the particular aforementioned state. Finally, the equivalence is generalized to wider classes of quantum walks and a limit theorem for the alternate walk in this context is presented.
This article addresses the planar Coleman--Gurtin heat equation with memory on a bounded domain, with rough anisotropic diffusion $A_μ$, typical of heterogeneous or composite media and encoded by a Beltrami coefficient $μ\in L^\infty(Ω)$ satisfying $\|μ\|_{\infty}<1$. First, under no additional smoothness assumptions on $μ$, solutions with $H^1_0(Ω)$-based initial data enter a time-averaged $L^\infty(Ω)$ regime, and instantaneously regularize into the second-order graph space $D(A_μ)$. Assuming in addition $μ\in W^{1,2}(Ω)$, this regularization upgrades to $W^{2,p}(Ω)$ for every $1<p<2$, and we construct regular global and exponential attractors of finite fractal dimension, for both the $L^2(Ω)$ and $H^1_0(Ω)$-based dynamics. The proof combines the instantaneous smoothing method of Chekroun, Di Plinio, Glatt-Holtz and Pata with maximal parabolic regularity for divergence-form operators with measurable coefficients, and with planar quasiconformal Beltrami estimates recently obtained in work by Green, Wick and the author.
The main component of the NextGeneration EU (NGEU) program is the Recovery and Resilience Facility (RRF), spanning an implementation period between 2021 and 2026. The RRF also includes a monitoring system: every six months, each country is required to send an update on the progress of the plan against 14 common indicators, measured on specific quantitative scales. The aim of this paper is to present the first empirical evidence on this system, while, at the same time, emphasizing the potential of its integration with the sustainable development framework (SDGs). We propose to develop a first linkage between the 14 common indicators and the SDGs which allows us to produce a composite index (SDGs-RRF) for France, Germany, Italy, and Spain for the period 2014-2021. Over this time, widespread improvements in the composite index across the four countries led to a partial reduction of the divergence. The proposed approach represents a first step towards a wider use of the SDGs for the assessment of the RRF, in line with their use in the European Semester documents prepared by the European Commission.
Even if laboratory practice is essential for all scientific branches of knowledge, it is often neglected at High School, due to lack of time and/or resources. To establish a closer contact between school and experimental sciences, the University Sapienza of Roma and the Istituto Nazionale di Fisica Nucleare (INFN) launched the Lab2Go project, with the goal of spreading laboratory practice among students and teachers in high schools.