Re[incontri] di Fisica Partenopea

Euclid has been launched in July 2023 with the first internal Data Release DR1 planned for December 2024. While Euclid has primarily been optimised for the study of dark matter and dark energy, the wealth of data it will accumulate promises groundbreaking insights into Active Galactic Nuclei (AGN), their origins, and their evolution.
In this talk I will show you how Euclid will identify and characterised AGN by using spectroscopy and photometry, providing a great amount of information to investigate fundamental open issues, such as the AGN demography and AGN evolution with redshift and luminosity, tracing the growth of BHs and providing an important constraint on galaxy/AGN evolution models.

In this talk I will present some of the results from the first 2 years of JWST data. In particular, I will talk about the results from the MIRI GTO high-z team, that I am a part of, concerning intermediate to high redshift galaxies.
The results I will present have been obtained using the combination of several instruments on board of JWST: NIRCam, MIRI, NIRISS, in both imaging and spectroscopic mode. Moreover, I will talk about what are the scientific challenges we hope to overcome with the next round of data.

The Pierre Auger Observatory is the largest facility in the world for studying ultra-high-energy cosmic rays. The Observatory is located in Argentina and consists of more than 1600 water Cherenkov detectors spread over an area of 3000 km^2 overlooked by Fluorescence detectors. The first phase of the Observatory’s data-taking began in 2004 and continued until the end of 2021. Now a new phase is starting with the upgraded AugerPrime detector. The Auger Observatory was designed to investigate the composition, energy and arrival directions of ultra-high-energy cosmic rays studying the extensive air showers produced in the Earth atmosphere, but has proven to be also a unique instrument to detect in unprecedented detail phenomena related to atmospheric electricity, as ELVES and downward TGFs. I will describe the work I carried out as a member of the Auger Collaboration starting from composition studies, passing through the optimization of AugerPrime, up to atmospheric electricity studies.

The process of coherent elastic neutrino nucleus scattering (CEvNS) was predicted more than 45 years ago within the Standard Model of elementary particles. The cross section of this process depends quadratically on the number of neutrons in the nuclei and thus prevails over all other known neutrino interactions. Therefore, this process is very interesting as a possible tool for nuclear reactor monitoring and nonproliferation tasks, and as a probe for the physics beyond the Standard Model. However, due to very low recoil energy, this process was not observed until recently. The first measurement was provided by the COHERENT experiment in 2017 with the CsI detector. In this talk, an overview of the COHERENT experiment will be presented with a main focus on the liquid argon (LAr) program.

La spettroscopia nucleare in Italia è nata agli inizi degli anni ’60 a Napoli, con l’arrivo di Renato Angelo Ricci. Essa ebbe inizio con una intensa attività sperimentale presso il padiglione 19 della Mostra d’Oltremare, mirata alla determinazione di nuovi schemi di decadimento nucleari. La produzione di specie nucleari radioattive veniva effettuata con un fascio di neutroni da 14 MeV, generati attraverso la reazione (d,t) con l’acceleratore HVEC da 400 kV, e misurando la radiazione gamma di decadimento tramite la tecnica di rivelazione a scintillazione. Il punto di partenza fu lo studio dello spettro dei raggi gamma emessi dal nucleo eccitato 50Ti, formato nel decadimento beta del nucleo 50Sc prodotto dalla reazione 50Ti(n,p)50Sc. Nel presente contributo verranno illustrate le tappe più significative dell’inizio di questo nuovo campo di ricerca unitamente al ruolo che esso ha avuto nella nascita della Sezione INFN di Napoli nel 1963, e nel susseguente sviluppo delle numerose attività di ricerca che oggi vedono impegnati la Sezione INFN e il Dipartimento di Fisica ‘Ettore Pancini’ dell’Università Federico II. A fronte dell’alto valore storico, scientifico e culturale del padiglione 19 e di altri luoghi della Mostra d’Oltremare, dove si sono svolte negli anni le attività di indagine e di formazione delle ricercatrici e dei ricercatori in fisica, essi giacciono oggi in disuso e in uno stato di completo abbandono. La seconda parte del presente contributo sarà dedicata a questo problema, ed alla presentazione dell’Associazione ‘All’Ombra del Cervo di Rodi’ costituita recentemente, con lo scopo di valorizzare e recuperare le aree di proprietà dell’Ente Mostra d’Oltremare di tutto il complesso costituito dai padiglioni 16 e 19, dall’Aula di Rodi e dalle altre strutture annesse, che dall’attuale stato di inattività e declino, sarebbe importante e doveroso recuperare alla comunità.

Exchange interactions were introduced by W. Heisenberg in 1926 in the context of the quantum mechanics of systems of identical particles, and soon allowed to successfully address numerous problems in atomic, molecular, and condensed matter physics, such as multi-electron atomic spectra, chemical bonds, ferromagnetism, and electron-electron collisions. After the discovery of the neutron in 1932, this concept allowed the systematic application of quantum mechanics to nuclear physics, being the basis of theories of nuclear structure developed, among others, by Heisenberg and E. Majorana. Over the subsequent decades, this idea morphed into the modern understanding of fundamental forces as mediated by virtual particle exchange, in the context of quantum field theory. In this long story, a crucial role was played by two Japanese physicists, H. Yukawa and S. Tomonaga, who were among the first Japanese to be exposed to the principles of the new quantum mechanics, and were strongly influenced by the above mentioned work. Within a few years, Yukawa conceived his decisive idea of a nuclear interaction mediated by virtual mesons, acknowledging crucial input by Tomonaga, who in the same period was investigating the range of proton-neutron interactions. In this contribution, we reconstruct the role played by Japanese physicists in the 1930s, towards the modern understanding of fundamental forces. A clear picture emerges also of the influence of European scientists in shaping the development of quantum concepts in Japan.

In an era dominated by the digital landscape, the ascent of network platforms defies traditional expectations, exhibiting an "unreasonable" growth that demands exploration. This presentation delves into the enigmatic forces propelling the explosive expansion of network platforms, ranging from social media giants to emerging digital ecosystems. As we dissect the unconventional strategies and dynamics fueling their meteoric rise, we challenge conventional notions of scalability and influence. Through unraveling the mysteries behind their extraordinary growth, this presentation aims to provide valuable insights for industry professionals, researchers, and enthusiasts seeking to navigate and understand the ever-evolving realm of network platforms. I will accompany you on a journey to decode the seemingly irrational trajectories of these platforms and explore the implications for technology, business, and society as a whole.seeking to navigate and understand the ever-evolving realm of network platforms. Join us on a journey to decode the seemingly irrational trajectories of these platforms and explore the implications for technology, business, and society as a whole.

Human genetics provides a robust avenue for causal inference, avoiding the pitfalls of reverse causation thanks to the stable nature of the genome. Specifically, Mendelian randomization (MR) can leverage genetic information to assess causal relationships between risk factors and disease outcomes. For example, through MR, researchers have confirmed the detrimental impact of LDL cholesterol in cardiovascular diseases and discarded the protective role of HDL in the same set of conditions. Although its generality, applications of MR have been limited to the analysis of single risk factors and outcomes in isolation.

In this talk, I will show how one can integrate machine learning and MR to train aggregate predictors of disease risk from multiple risk factors, a new framework that we call Differentiable MR (DMR). At its core, DMR aligns genetic influences of composite risk factors with those of the disease under study, bringing principles of causality in disease risk assessment. Finally, my presentation also aims to showcase how the physicists' mindset can be channeled to tackle quantitative problems in other disciplines, with guiding examples in machine learning for biomedicine.

Recent technologies, such as Hi-C [1], have revealed that the mammalian genome has a complex, far from
random three-dimensional (3D) organization, intimately linked to vital biological processes. To rationalize
the complexity of experimental data, polymer models from Statistical Physics and a variety of
computational methods have been developed [2,3]. However, they typically cannot explain data at the scale
of the full genome.
In this talk, I will present the first genome-wide extension of PRISMR [4], our approach that combines
Machine Learning and Polymer Physics to infer the different types of DNA binding sites determining
genome 3D structure. The genome-wide study allowed us to develop a code linking chromosome 3D
structure to chromatin states through our inferred binding domains. Interestingly, they have an overlapping,
combinatorial organization along chromosomes necessary to accurately explain contact specificity. The
binding domains and the associated architectural code were tested by making predictions on the changes of
the 3D structure caused by a set of genomic mutations at the Sox9 locus linked to human diseases and our
predictions were confirmed by independent data from cells carrying such mutations. Finally, in a reverse
approach based on the discovered code, we predicted de novo the 3D structure of an independent set of
chromosomes from only their 1D chromatin marks, thus validating the inferred epigenetic-architecture
code [4].
Overall, our results shed light on how 3D information is encrypted in 1D chromatin via the specific
combinatorial arrangement of binding sites.

References

[1] R. Kempfer, A. Pombo, Nature reviews Genetics 21 (2020)
[2] Barbieri et al. Proc. Natl. Acad. Sci. USA 109 (2012)
[3] Bianco et al. Nat. Genet. 50 (2018)
[4] Esposito et al. Cell Reports 38 (2022)

In the current era of precision cosmology, there is a growing interest in using new probes to explore the evolution of the universe and extend the mapping of its expansion to include currently uncovered redshift ranges.
In this talk, I will introduce the possibility of using Quasars as
cosmological probes, which have the potential to expand the Hubble diagram of Supernovae to z = 2.4 - 7.5, allowing us to distinguish between predictions of different cosmological models. Additionally, I will test several dark energy models using Quasar data and investigate their possible incompatibilities with measurements from Baryonic Acoustic Oscillations, Dark Energy Survey and Cosmic Microwave Background radiation.

In this chat I am going to talk about galaxy evolution in dense environments and the different techniques and equipment we use to shed light on this topic.
As an example, I will mention how we use Virtual Reality (a tool developed for gaming) to visualize and analyze astronomical 3D data. In the second part of the talk I will focus on my personal “evolutionary path” as an astronomer. I will tell why I decided to move to Naples and work at the Observatory of Capodimonte.
Moving from theoretical physics to astronomy and astrophysics, jumping from one country to another: the life of researchers is more complex but as exciting as galaxy evolution.

In this talk, I will present a novel method for inferring the mass composition of Ultra High Energy Cosmic Rays (UHECR) from the electromagnetic profile of their air showers. By capturing the main features of the profile in few moments of the distribution, we can use nested sampling algorithms to probe the full shape of the likelihood. Furthermore, I will explore opportunities for enhancing the statistical significance of this dataset by exploiting its correlation with other shower observables.

This talk will provide an overview of the DarkSide-20k experiment by the Global Argon Dark Matter Collaboration. This experiment aims to explore the WIMP hypothesis by detecting WIMP-nucleon elastic scattering with a dual-phase time projection chamber (TPC) detector filled with low-radioactivity underground liquid argon. We will discuss the current status of the experiment, as well as the involvement of the Cryogenic Laboratory of our department in the testing of photo-detection systems with a dedicated cryogenic testing facility and R&D with Proto-0, a small-scale prototype of DarkSide-20k.

The evolution of the trapping horizon of a black hole in the presence of infalling matter can be understood as a backreaction effect. Focusing on low-frequency scalar radiation and spherically symmetric black holes, I will show that a simple closed-form expression for the expansion rate of the horizon can be derived in terms of the initial data for the scalar field on past null infinity. This is achieved by solving the Einstein field equations to second order in perturbation theory in the vicinity of the horizon, and then using matched asymptotics expansions to compute the evolution of wave packets through the potential barrier. Applications of this framework to more general matter fields will be also discussed.

We will briefly summarize some recent results obtained in the Hamiltonian formalism for the Brans-Dicke theory. We will show that these results can be used to address equivalence (if any…) between Jordan and Einstein Frames. Although we will show that there is a mathematical equivalence between these two frames, a pair of examples points out that the two frames do not look to be physically equivalent.

In this talk we will discuss the theory of reduction of phase space, in terms of Poisson geometry, and the open problem of the diagram reductio-quantization in the setting of deformation quantization.

I am the lead scientist for archive and data processing operations at the Chandra X-ray Center. In this talk, I will shortly describe what it is like for an astrophysicist to be working in the operations of a big mission like Chandra and will describe the main traits of my professional development that led me to my current position. I will emphasize opportunities and challenges of this career path and provide some advices I wished I had known when I was a student (or shortly thereafter) based on my experience.

The explosion of SN1987A is the only case in history in which a neutrino signal from a nearby supernova (SN) has been observed, and has shaped our understanding of the inner mechanisms of SNe.
In this talk, we revisit the interpretation of SN1987A from a modern perspective. We compare up-to-date SN models with the legacy data, showing a general consistency in the time-integrated properties. The neutrino signal, both in the accretion-dominated and in the cooling-dominated phase, agrees with the observations if the central protoneutron star is light enough, allowing us to infer a range for the initial mass of the remnant. The inclusion of convection and updated neutrino-nucleon opacities in the current models, compared to the historical ones, leads to a shortened duration of the burst, in tension with the observed signal duration. This suggests a second, independent phase of emission to explain the late-time observed events.

Primordial Black holes with mass of 10^15 g should have been evaporated by now giving potentially access to the physics of the Early Universe. In particular, the presence of PBH could have impacted the process of leptogenesis in different ways depending on the mass and so on the temperature of the PBHs. We present the impact of the non-standard cosmology driven by the presence and the evaporation of light primordial black holes on the production of the baryon asymmetry of the Universe in different scenarios of leptogenesis.