O entendimento dos fenômenos associados com a dinâmica de convergência dos estados quânticos e fundamental para o avanço da teoria da informação quântica. Este trabalho apresenta uma introdução ao formalismo matemático necessário para a análise de sistemas quânticos dissipativos, através da álgebra de semigrupos de operadores completamente positivos que preservam traço, e uma breve discussão sobre os princípios da teoria da informação. Posteriormente e introduzido o conceito de cutoff e são expostas algumas definições matemáticas relacionadas a distinguibilidade de estados quânticos e ao próprio fenômeno de cutoff. O comportamento de cutoff é demonstrado para duas classes de semigrupos: de operadores gerados por lindbladianos comutantes e de operadores constituídos de sequências de produtos tensoriais. Por fim, discutem-se direções futuras deste estudo no contexto do modelo de computação quântica dissipativa e de passeios aleatórios quânticos abertos.

Electron Beam Ion Traps (EBITs) provide a controlled environment for studying electron-ion interactions, particularly in highly charged ions (HCIs), and enable precise measurement of processes, such as dielectronic recombination (DR). Using the compact Dresden EBIT at Jagiellonian University, we present new experimental data on DR in neon ions, collected for electron energy scanned in range of 700 to 1000 eV. The data were obtained with a silicon-drift X-ray detector (Bruker XFlash 5030), and results indicate resonant structures corresponding to DR, with the observed resonant-like Kβ emission primarily attributed to He-like neon ions. However, low statistical precision highlights the challenges of achieving optimal signal quality in this setup, particularly due to low detection efficiency in the K-shell neon energy range. Planned improvements, including repositioning the detector closer to the trap and removing the beryllium window, are expected to enhance resolution and data acquisition efficiency in future studies.

We prove that the Hardy–Littlewood maximal operator M is bounded on the variable Lebesgue space Lp(·)(X,d,μ), with 1<p-≤p+<∞, over an unbounded space of homogeneous type (X,d,μ) with a Borel-semiregular measure μ, if and only if the averaging operators TQ are bounded on Lp(·)(X,d,μ) uniformly over all families Q of pairwise disjoint “cubes” from a Hytönen–Kairema dyadic system on X. This extends Diening’s well-known characterization of the boundedness of M on Lp(·)(Rn) to the setting of spaces of homogeneous type, while also providing a slight refinement of the original result.

We present a summary of research that we have conducted employing AI to better understand human morality. This summary adumbrates theoretical fundamentals and considers how to regulate development of powerful new AI technologies. The latter research aim is benevolent AI, with fair distribution of benefits associated with the development of these and related technologies, avoiding disparities of power and wealth due to unregulated competition. Our approach avoids statistical models employed in other approaches to solve moral dilemmas, because these are “blind” to natural constraints on moral agents, and risk perpetuating mistakes. Instead, our approach employs, for instance, psychologically realistic counterfactual reasoning in group dynamics. The present paper reviews studies involving factors fundamental to human moral motivation, including egoism vs. altruism, commitment vs. defaulting, guilt vs. non-guilt, apology plus forgiveness, counterfactual collaboration, among other factors fundamental in the motivation of moral action. These being basic elements in most moral systems, our studies deliver generalizable conclusions that inform efforts to achieve greater sustainability and global benefit, regardless of cultural specificities in constituents.

The main objective of this study is to obtain three-dimensional empirical K-shell x-ray fluorescence cross-section ( σ K α , σ K β and σ K tot ) values for a wide range of elements 16 ≤ Z ≤ 92 for photons with energies from 5.46 keV to 123.6 keV, using more than 3300 experimental data values published between 1985 and 2023 by numerous researchers. These data values are fitted using an interpolation method including a three-dimensional function against atomic number Z and excitation energy E, resulting in a three-dimensional plot to estimate empirically a three-dimensional set of K α , K β and K tot x-ray fluorescence cross sections. The results of this empirical calculation are compared, for selected elements, with other empirical and experimental values reported in the literature, and a reasonable agreement is observed.

Mathematical models are increasingly adopted for setting disease prevention and control targets. As model-informed policies are implemented, however, the inaccuracies of some forecasts become apparent, for example overprediction of infection burdens and intervention impacts. Here, we attribute these discrepancies to methodological limitations in capturing the heterogeneities of real-world systems. The mechanisms underpinning risk factors of infection and their interactions determine individual propensities to acquire disease. These factors are potentially so numerous and complex that to attain a full mechanistic description is likely unfeasible. To contribute constructively to the development of health policies, model developers either leave factors out (reductionism) or adopt a broader but coarse description (holism). In our view, predictive capacity requires holistic descriptions of heterogeneity which are currently underutilised in infectious disease epidemiology, in comparison to other population disciplines, such as non-communicable disease epidemiology, demography, ecology and evolution.

Markov chain models are used in several applications and different areas of study. A Markov chain model is usually assumed to be homogeneous in the sense that the transition probabilities are time-invariant. Yet, ignoring the inhomogeneous nature of a stochastic process by disregarding the presence of structural breaks can lead to misleading conclusions. Several methodologies are currently proposed for detecting structural breaks in a Markov chain. However, these methods have some limitations: namely they can only test directly for the presence of a single structural break. This paper proposes a new methodology for detecting and testing the presence of multiple structural breaks in a Markov chain occurring at unknown dates.

We describe constant mean curvature surfaces with harmonic left-invariant Gauss map in three-dimensional unimodular Lie groups endowed with left-invariant metrics that are also right-invariant with respect to one-dimensional Lie subgroups, as well as in the hyperbolic space.

The CMS detector will be upgraded for the HL-LHC to include a MIP Timing Detector (MTD). The MTD will consist of barrel and endcap timing layers, BTL and ETL respectively, providing precision timing of charged particles. The BTL sensors are based on LYSO:Ce scintillation crystals coupled to SiPMs with TOFHIR2 ASICs for the front-end readout. A resolution of 30-60 ps for MIP signals at a rate of 2.5 Mhit/s per channel is expected along the HL-LHC lifetime. We present an overview of the TOFHIR2 requirements and design, simulation results and measurements with TOFHIR2 ASICs. The measurements of TOFHIR2 associated to sensor modules were performed in different test setups using internal test pulses or blue and UV laser pulses emulating the signals expected in the experiment. The measurements show a time resolution of 24 ps initially during Beginning of Operation (BoO) and 58 ps at End of Operation (EoO) conditions, matching well the BTL requirements. We also showed that the time resolution is stable up to the highest expected MIP rate. Extensive radiation tests were performed, both with x-rays and heavy ions, showing that TOFHIR2 is not affected by the radiation environment during the experiment lifetime.

In fusion materials research using ion beam analysis techniques, the reactions 9Be(3He,pi )11B (i = 0, 1, 2…) are relevant to probe Be-related plasma-wall interactions. The cross sections for this reaction have been examined previously; nevertheless, there is a ∼40% difference in the studied energy interval between the two most relevant earlier studies. Therefore, a new data set for the differential cross sections 9Be(3He,pi )11B for the proton groups i = 0, 1, …, 9 is given. The measurements were performed using a thin beryllium film in the laboratory energy range from 1.0 MeV to 2.5 MeV in steps of 50 keV for lab angles from 115° to 165° to the incoming beam direction in steps of 10°. Additional measurements for intermediate angles were performed over the same energy range in steps of 250 keV. The results are in good agreement with one of the previous studies and a benchmarking measurement was performed against the yield of a beryllium thick target at 2.5 MeV for 135°.