Re[incontri] di Fisica Partenopea

In the nucleus of cells, chromosomes have been discovered to self-organize into a complex spatial architecture that serves vital functional purposes as, for instance, genes have to establish specific physical contacts with their distal DNA regulators to control transcriptional activities. However, how the system self-assembles to shape the folding of our genome and its functions is only poorly understood. In this talk, I discuss principled models of interacting polymers from statistical mechanics to investigate the mechanisms whereby distal DNA sequences recognise and interact with each other. Those theories are validated against independent experiments, opening to new tools for real-world applications, such as the prediction of the effects of disease-associated mutations, linked to congenital disorders or cancer, on genome 3D structure.

Understanding the dynamics of infectious disease spread in interconnected populations is crucial for effective public health planning. In our increasingly mobile world, traditional modeling approaches often fall short in capturing the complexities of disease transmission across vast distances. This paper presents an innovative framework that combines the conceptual simplicity of ordinary differential equations (ODEs) with the predictive capabilities of computational models to analyze epidemic dynamics on interconnected networks. We derive scaling laws for epidemic propagation delays using perturbation expansion techniques, highlighting the influence of network topology and migration flux. Our findings reveal the diminishing returns of mobility reduction policies in mitigating epidemic spread, particularly after the outbreak has settled. This work contributes to a deeper understanding of the mechanisms driving infectious disease dynamics, providing quantitative insights for public health authorities to assess risks and optimize response strategies.

Chromosomes have a complex spatial structure that serves vital functional purposes, yet their self-organization principles are largely unknown. I discuss our recent work combining polymer physics and machine learning to understand how chromosomes are folded and regulated in the cell nucleus. After a brief overview of recent experimental advances to measure chromosome 3D structure, I discuss our physics models showing that phase transition mechanisms can control chromosome architecture and its link with gene regulation and cell function. Several experiments have confirmed those models, notably their predictions on how genetic mutations result in diseases such as congenital disorders, opening the way to novel applications in biomedicine.

Within the cell nucleus of eukaryotic organisms, chromosomes are organized in a complex, non-random three-dimensional (3D) spatial structure, which is intimately linked to vital functional purposes. Indeed, a correct folding allows an efficient communication between genes and their distal regulatory elements while, if altered, can cause severe diseases. Here I will discuss how Polymer Physics, combined with Molecular Dynamics simulations and Machine Learning based inference, represent a powerful tool to quantitatively investigate the complexity of 3D organization of real genomes, as highlighted by recent microscopy and biochemical experiments. I will show that simple physical processes, widely studied in Statistical Mechanics, such as phase-separation of molecular aggregates and symmetry breaking mechanisms, allow us to make sense of recent experimental observations including the in olfactory receptor choice in olfactory sensory neurons (OSN). Finally, polymer models can be used to study the impact of disease-linked genetic mutations or the effect of viral infections as SARS-CoV-2, opening the way to new potential tools in Biomedicine.

I will describe the activity aimed at characterising AGN through their variability in preparation for next generation LSST surveys.

The purpose of this work is to understand if, among the blazars not detected by Fermi-LAT, a population of TeV emitting sources could be detected by current or future Cherenkov telescopes. We cross-matched the 5BZCAT catalog of blazars with the most recent catalogs of point-like source, to determine if the X-ray emission can be used as an effective proxy to find and characterize candidate TeV-emitting blazars.

I will talk about the recent discoveries on high redshift galaxies made by JWST in the last year, and what we can expect from the next rounds of observations.

The recent data by the JWST satellite identify what seems an excess of luminous objects in the early Universe. It has been proposed that this may be evidence that exotic monsters lurk in the cosmic Dark Ages.
I will show how -while such excesses seems to be consistent and real- they can not be explained by some of the most extreme versions of "dark matter supported stellar objects" that myself and others postulated in the past, contrary to the claims in this sense.

I will present a project collecting machine learning tools to extract physical parameters from the major sky surveys and predict the cosmological parameters using million to billion galaxy samples.

Nel paradigma della Relatività Generale, l'attrazione gravitazionale è un fenomeno geometrico dello spaziotempo avvertito tanto dai corpi massivi che dai campi puramente energetici, come il campo elettromagnetico. In quest'ottica, anche il concetto di peso cambia, perchè non dipende solo dalla quantità di materia ma anche dall'energia interna. Trattandosi di una teoria classica, si ritiene plausibile l'effetto di attrazione sui campi classici, ma non è ovvio immaginare questo fenomeno sui campi quantistici, a causa delle divergenze nel calcolo dell'energia di vuoto.
L'esperimento ARCHIMEDES (INFN - CSN2) si propone di misurare la variazione di peso di un cristallo superconduttivo di BSCCO mentre viene indotta una variazione di energia di vuoto interna dalla transizione di fase. La variazione di peso attesa è così piccola (0.5 fN) che è stato necessario costruire ad hoc una bilancia opto-meccanica di alta precisione operante presso il futuro SUN Laboratory (Lula, NU), essendo la Sardegna uno dei luoghi con rumore sismico più basso d'Europa.

In the paradigm of General Relativity (GR), gravitational attraction is a geometric phenomenon of spacetime felt by both massive bodies and massless fields, such as the electromagnetic field. In this context, the concept of weight also changes, because it depends not only on the amount of matter but also on internal energy. Since GR is a classical theory, the effect of attraction on classical fields is considered plausible, but it is not obvious to imagine this phenomenon on quantum fields, due to divergences in the calculation of vacuum energy. The ARCHIMEDES experiment (INFN - CSN2) aims to measure the weight change of a superconducting BSCCO crystal while an internal vacuum energy variation is induced by the phase transition. The expected weight variation is so small (0.5 fN) that a high-precision opto-mechanical balance had to be built ad hoc at the future SUN Laboratory (Lula, NU), Sardinia being one of the places with the lowest seismic noise in Europe.

Superconducting nanowires represent a rapidly developing technology with a broad spectrum of applications in fields such as space communications, lidar, and quantum information science. This talk explores the potential of using superconducting nanowires both as targets and sensors for the direct detection of sub-GeV dark matter.
These devices offer exceptional sensitivity to small energy deposits in electrons and demonstrate remarkably low dark count rates, making them ideal for probing electron recoils resulting from dark matter scattering and absorption interactions. We present sensitivity plots for a 4.2 ng NbN device with a dark count rate of $5\times10^{-4}s^{-1}$ dark count rate and discuss the projected sensitivities for larger detectors.

The DarkSide-20k is a 20-tonne fiducial mass dual phase Liquid Argon Time Projection Chamber (LArTPC) detector for the direct dark matter search, filled with low radioactivity Argon and equipped with customised cryogenic SiPM photosensors. The experiment will be constructed in INFN Gran Sasso underground Laboratory (LNGS), and is expected to be free of any instrumental background for an exposure of >100 tonne year.
The DarkSide SiPMs were developed specifically for LAr use in collaboration with Fondazione Bruno Kessler (FBK). This activity leaded to the production and assembly of large surface arrays of SiPMs (20×20 cm2) the Photo Detection Units (PDU) in a INFN dedicated production site NOA at LNGS. The total of 528 PDUs will be produced in the following year to be allocated on the two Optical Planes (OP) of the TPC (with ~21 m2 total SiPM surface).
All PDUs before installation on the OP must be tested and qualified in LN, this will done in a dedicated test facility (PDU Test Facility) designed, assembled and commissioned in Naples Cryogenic Laboratory for the Dark Matter Direct Searches of UNINA Physics Department.
Two one-month long testing campaigns with very first 6 and later 10 PDUs were conducted in Naples in May and October of 2024. The PDUs were tested for varying over-voltage values and different readout and power configurations. The key parameters like SPE position, Base line RMS, signal-to-noise ratio, Gain and Sensitivity as a function of time were acquired for the stability study. The description of tests and results will be presented in this talk.

DarkSide-Proto0 (Proto0) is an experiment developed within the DarkSide-20k project, a dark matter direct detection experiment that aims to hunt for WIMPs using a two-phase argon time projection chamber (TPC). In preparation for the future DS-20k experiment, Proto0 focuses on investigating and optimizing the production of the ionization signal (S2) in two-phase argon TPCs and validating many of the novel technologies featured in the DS-20k detector on a smaller scale. To achieve this, Proto0 is equipped with a compact TPC designed to accommodate two PDUs, the 20x20 cm² SiPM-based photon counters developed for DS-20k. The main feature of the Proto0 detector is its flexible TPC design, with independently moving components during operation. This enables an optimization study of S2 formation in relation to geometrical factors and electrical properties. The results obtained from Proto0’s scientific program will help fine-tune the DS-20k TPC design and contribute to a broader understanding of the engineering behind future two-phase experiments. The experiment is currently located at the cryogenic laboratory of Unina/INFN Napoli, where it is collecting data using a specially designed cryogenic setup, complete with argon condensation, recirculation, and purification loops.

In this talk I will present the famous Kontsevich Formality theorem, which solves the problem of quantization for any Poisson manifolds. Poisson manifolds encodes the information of classical mechanical systems, while quantum systems are encoded by star products. Kontsevich proved that for any Poisson manifold there exists a star product by proving that we can construct a(n L-infinity) morphism connecting those structures.

Oxygen, the lifeblood of all living beings, is both a blessing and a challenge for us material physicists working on the materials growth for electronics. Superconductivity, ferroelectricity, ferromagnetism, and multiferroicity—these remarkable properties of materials in oxides electronics are intrinsically linked to the presence of oxygen. In this presentation, we will explore how oxygen plays a pivotal role in these phenomena.

Superconducting nanowire single photon detectors (SNSPDs) are advanced devices renowned for their high sensitivity, low noise, and fast speed, making them ideal for single photon detection applications such as quantum communication, photonic quantum computing, imaging, and LIDAR. Today, I will share the advanced SNSPD technologies developed by our group and discuss our efforts to transition these innovations from research to industry.

Dopo il dottorato in Fisica teorica ed un breve periodo come Post-doc, ho sperimentato gli ambienti di lavoro di una start-up, di una grande azienda e di una scuola superiore. Finché ho deciso di provare a costruire una carriera come fisico freelance.
Oggi (novembre 2024) insegno matematica e fisica in un liceo per la metà del tempo, e faccio il fisico freelance per l'altra metà.
Questo talk è duplice. Nella prima parte, parlerò della fisica computazionale come strumento didattico per la scuola superiore. Nella seconda, farò una panoramica delle mia attività come Fisico libero professionista, con l'auspicio che possano ispirare chiunque cerchi attività alternative all'accademia, alla grande azienda e al sistema scolastico.

Su come ho fatto di tutto per non accettare l'invito del professor Iocco, non riuscendoci.

Alcune considerazioni sulla comunicazione della scienza, maturate nella mia esperienza personale tra scuole, festival, libri, tv e teatro.

The Former Physics Pavilions of the Mostra d’Oltremare house a unique scientific and cultural heritage, bearing witness to a period of great innovation and intellectual activity. Today, these historic spaces offer an extraordinary opportunity to become a catalyst for social and cultural development through the establishment of a Center of Excellence dedicated to innovative scientific and technological research, continuous education and training, as well as dissemination of scientific knowledge. The restoration and revitalization of these pavilions is the central mission of the "All’Ombra del Cervo di Rodi" Association, which recently organized a workshop to identify potential research opportunities, technological advancements, and educational initiatives that could shape the envisioned Center of Excellence. Starting with a brief historical overview, the workshop’s key activities will be presented, alongside preliminary concepts for a feasibility plan aimed at creating a Center of Excellence, which could be focused on quantum research and implementations, as well as on continuous education.