The 6th Bego Rencontre Summer School

4 Jul 2022, 09:00 → 14 Jul 2022, 18:15 Europe/Paris

Remo Ruffini (ICRANet, ICRA, INAF)

This meeting extends across two weeks from 4-14 July 2022. It aims to discuss recent developments in the theory and observations of gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and dark matter (DM).

 

Some relevant topics to be discussed and devoted to GRBs and AGNs are:

• The energy extraction process from rotating black holes (BHs) in the inner engine of the high-energy (e.g. GeV) emission of long GRBs and AGNs. Special attention is given to inner engines comprising a Kerr BH immersed in a magnetic field and ionized plasma. Recent developments on the topic, especially the problem of field screening, electric discharge, radiation properties, black hole physics, magnetohydrodynamics, and the maximum electric charge allowed in the inner engines, will be discussed.
• Recent progress in GRB theory, for instance in the binary-driven hypernova (BdHN) model. This includes the physical explanation of the ultrarelativistic prompt emission (UPE) phase in the MeV regime, the afterglow emission in the X-rays, optical, and radio wavelengths, and the GeV emission.
• Supernova associated with GRBs. The role of the supernova explosion in the entire emission of a long GRB.
• GRBs at high-redshift and GRB-cosmology.
• The emission of GRB cocoons. Observations.
• The emission of M87*. Theory and observations.

 

Some relevant topics to be discussed and devoted to dark matter are:

• Fermionic and bosonic dark matter: microphysics.
• Fermionic and bosonic dark matter: macrophysics.
• Recent developments in the description of the Galactic center (Sgr A*) as a core of dark matter.
• Latest astrometric observations of stars orbiting Sgr A* and observational constraints on the nature of Sgr A*.
• Latest news on the baryonic content in galaxies.
• Strong gravitational lensing.
• Dark matter in early cosmology. Cosmological simulations. Dark matter halo formation.

 

The meeting will be held in the Villa Ratti, the seat of ICRANet in Nice, France, and will follow a mixed format, in presence and online.

 

Invited speakers (TBC)

• Aimuratov Yerlan
• Amati Lorenzo
• Arguelles Carlos Raul
• Astesiano Davide
• Becerra Bayona Laura
• Bianco Carlo Luciano
• Bondani Stefano
• Boshkayev Kuantay
• Crespi Valentina
• Crosta Mariateresa
• Dainotti Maria Giovanna
• Della Valle Massimo
• Fryer Christopher
• Gregoris Daniele
• Izzo Luca 
• Kotlarik Petr
• Li Liang 
• Longo Francesco
• Luo Wentao
• Mavromatos Nick
• Meneghetti Massimo
• Mestre Martin
• Mirabel Felix
• Moradi Rahim 
• Nakar Ehud
• Peissker Florian
• Petrosian Vahe
• Piran Tsvi 
• Re Federico
• Re Fiorentin Paola
• Rodriguez Ruiz José Fernando
• Rosati Piero
• Rueda Hernandez Jorge Armando
• Ruffini Remo
• Sahakyan Narek
• Sigismondi Costantino
• Spagna Alessandro
• Troja Eleonora
• Vereshchagin Gregory
• Viel Matteo
• Wang Yu
• Waxman Eli
• Xue Shesheng
• Yunis Rafael
• Zhang Bing

 

Registration fee:

• Regular fee: 150 Euros
• Reduced fee: 50 Euros (applied to students, retired scientists)

 

Final program.pdf

Monday, 4 July

09:00 → 12:15 Morning session: Dark Matter Galactic Center

Convener: Carlo Luciano Bianco (ICRANet)

09:00 Report on the July 1, 2022 ANVUR evaluation of ICRA and ICRANet

Speaker: Carlo Luciano Bianco (ICRANet)

09:45 Local Cosmology in the Gaia era

The Galactic stellar populations can be used to test the predictions made by the Cold Dark Matter (CDM) model and compared with the observations at high redshift. Thanks to the modern astrometric, photometric and spectroscopic stellar surveys we can identify the «building blocks» of the Milky Way. Studies based on the Gaia DR’s and ground based spectroscopic surveys have already identified a major merger of a dwarf galaxy (GSE) at z=2 (10 Gyr ago) plus the debris of various minor mergers and streams in the Galactic halo, as well as in the Galactic disc (Icarus).

Speaker: Alessandro Spagna

10:07 Local Cosmology in the Gaia era

The Galactic stellar populations can be used to test the predictions made by the Cold Dark Matter (CDM) model and compared with the observations at high redshift. Thanks to the modern astrometric, photometric and spectroscopic stellar surveys we can identify the «building blocks» of the Milky Way. Studies based on the Gaia DR’s and ground based spectroscopic surveys have already identified a major merger of a dwarf galaxy (GSE) at z=2 (10 Gyr ago) plus the debris of various minor mergers and streams in the Galactic halo, as well as in the Galactic disc (Icarus).

Speaker: Re Fiorentin Paola

10:30 TBD

Speaker: Florian Peissker

11:15 Coffee Break

11:30 The Intergalactic Medium as a cosmological probe

I will review the use of the Intergalactic Medium as a probe of fundamental physics.

Speaker: Prof. Matteo Viel

Tuesday, 5 July

09:00 → 13:00 Morning session: Dark Matter Galactic Center

Convener: Aldo Treves (Università Insubria)

09:00 Detectability of primordial black holes as a dark matter candidate with gravitational waves from the Galactic center

The inconclusive results in the search for a dark matter particle have led many to investigate primordial black holes as a possible alternative candidate. In my talk I will first review the basic theory of primordial black holes,
their potential role in the dark matter problem, and the observational constraints already in place in this regard. In the second part of my talk I will explore their potential detectability (and limitations thereof) at the Galactic center via gravitational waves with upcoming space-based interferometers LISA and muAres.

Speaker: Federico Re

09:45 Detectability of primordial black holes as a dark matter candidate with gravitational waves from the Galactic center

Speaker: Stefano Bondani (University of Insubria)

10:30 TBD

Speaker: Felix Mirabel (IAFE-Argentina)

11:15 Coffee Break

11:30 2022 ICTP-SAIFR Prize in Classical Gravity and Applications

Speaker: Carlos Raúl Argüelles (La Plata National University & ICRANet)

13:00 → 15:00 Lunch Break

17:00 → 18:00 Afternoon session: Dark Matter Galactic Center

Convener: Aldo Treves (Università Insubria)

17:00 Small-scale structure, self-interacting fermions, and cosmology

Speaker: Rafael Yunis

Wednesday, 6 July

09:00 → 13:00 Morning session: Dark Matter Galactic Center

Convener: Piero Rosati

09:00 Understanding Gravitational Entropy of Black Holes: A New Proposal via Curvature Invariants

Pioneered with the Christodoulou-Ruffini irreducible mass and subsequently reformulated with the Hawking-Bekenstein entropy, it can be shown that the area of the horizon of a black hole cannot decrease. Partly motivated by the arrow of time problem in cosmology and the Weyl curvature hypothesis, previous works in the literature have proposed - among other possibilities - the square of the Weyl curvature, as being the underlying entropy density function of black hole entropy, but the proposal suffers from a few drawbacks. In this work, we propose a new entropy density function also based solely on the Weyl curvature, but adopting some other combinations of curvature invariants. As an improvement we find that our method works for all static black hole solutions in four and five dimensional general relativity regardless of whether they are empty space solutions or not. It should also be possible to generalize our method to higher dimensions. This allows us to discuss the physical interpretation of black hole entropy, which remains somewhat mysterious. Extending to modified theories of gravity, our work also suggests that gravitational entropy in some theories is a manifestation of different physical effects since we need to choose different combinations of curvature quantities. My talk will be based on Phys. Rev. D 105, 104017 (2022).

Speaker: Daniele Gregoris (danielegregoris@libero.it)

09:45 RAR model: cosmological scales, galactic scales, and DM particle nature

Speaker: Carlos Raúl Argüelles (Universidad Nacional de La Plata)

10:30 TBD

Speakers: Carlos Raúl Argüelles (La Plata National University & ICRANet), Carlos Raúl Argüelles (Universidad Nacional de La Plata)

11:15 Coffe Break

11:30 Cosmography and tests of the LCDM paradigm with high-precision strong lensing modelling of galaxy clusters

I will show how high-precision strong lensing models of galaxy clusters based on high-quality HST imaging and spectroscopic VLT data can constrain the inner dark matter mass distribution of clusters and compared with cosmological simulations. The same lens models enable competitive time-delay cosmography and the study of high-redshift magnified star-forming galaxies.

Speaker: Piero Rosati

12:15 Constraining the core-halo structure of fermionic DM in the Galaxy with stellar streams

Speaker: Martin Mestre

13:00 → 15:00 Lunch Break

15:00 → 16:30 Afternoon session: TBD

Convener: Piero Rosati

15:00 Strong lensing constraints on the small scale structure of galaxy clusters

I will discuss how strong lensing can be used to constrain the small-scale structure of galaxy clusters. I will discuss how recent observational results compare with predictions from numerical hydrodynamical simulations. In particular, I will show that current simulations in the context of the LCDM cosmological model fail to reproduce the observed abundance of galaxy-galaxy strong lensing events in galaxy clusters.

Speaker: Massimo Meneghetti

15:45 S2 star dynamics in high Dark Matter densities around SgrA*

Speaker: Valentina Crespi

Thursday, 7 July

09:00 → 13:00 Morning session: AGNs

Convener: Gregory Vereshchagin (ICRANet)

09:00 TBD

Speaker: Kuantay Boshkayev (Kazakh National University)

09:45 W$ boson mass tension caused by its right-handed gauge coupling at high energies?

The recent high-precision measurement of the $W$ mass by the CDF collaboration is in $7.0~\sigma$ tension with the Standard Model (SM) expectation. This tension can be relieved if the $W$ boson possesses a non-trivial right-handed gauge coupling at high energies. Such a right-handed gauge coupling induces by the SM gauge symmetric four-fermion interactions at TeV scales, where SM fermions compose massive composite particles. We study the top-quark mass generated by spontaneous symmetry breaking and calculate the $W$ and $Z$ boson propagators and decays. The right-handed coupling corrections to their masses and widths are consistent with experimental measurements. We discuss the restoring parity-preserving gauge symmetries by the SM gauge bosons and composite
particles at TeV scales.

Speaker: She-Sheng Xue (ICRANet, Physics Department, Sapienza University of Rome)

10:30 TBD

Speaker: Narek Sahakyan (ICRANet-Armenia)

11:15 Coffe Break

11:30 TBD

Speaker: Razmik Mirzoyan (Max-Planck-Institute for Physics)

12:15 The importance of the azimuth of sunrise and sunset in Archaeoastronomy: in memory of Francesco Giannini, collaborator of the ICRANet School Department

The measurement of the sunrise azimuth on the sea horizon of Pescara is made in the season 1-march to 4-july (and more) by using a fixed reference point in the foreground, and the coordinates y to the horizon level and x towards left (+) or right (-). The parabola obtained in this way will be analyzed with modern tools now available in many spreadsheets softwares. The comparison with the ephemerides of Stellarium allows to obtain the parallax angles to extrapolate the solar path down to the horizon in the case of clouds' covering.

Speaker: Costantino Sigismondi (ICRA Sapienza and ICRANET Pescara)

Sigismondi-abstract-87.pdf

13:00 → 15:00 Lunch Break

15:00 → 16:30 Afternoon session

Convener: Gregory Vereshchagin (ICRANet)

15:00 Ellipsoids evolution via GWs

Speaker: José Fernando Rodriguez Ruiz

Friday, 8 July

09:00 → 13:00 Morning session: Fronteer

Convener: Prof. She-Sheng Xue (ICRANet, Physics Department, Sapienza University of Rome)

09:00 TBD

Speaker: Di Li (National Astronomical Observatories, China)

09:45 TBD

Speaker: Lang Xie

10:10 TBD

Speaker: Zhi-Peng Jin

10:30 TBD

Speaker: Wentao Luo (USTC)

11:15 Coffe Break

11:30 TBD

Speaker: Mimoza Hafizi (University of Tirana)

12:15 Observations of GRB at HE and VHE energies: a long path to success

The lecture will review the path that led to the observation of GRBs at High and Very High Energies.

Speaker: Francesco Longo (University of Trieste and INFN, Trieste)

13:00 → 15:00 Lunch Break

15:00 → 15:45 Afternoon session

Convener: She-Sheng Xue (ICRANet, Physics Department, Sapienza University of Rome)

15:00 TBD

Speaker: Prof. Johann Rafelski

Monday, 11 July

09:00 → 13:00 Morning session: Cocoon and BdHN model

Convener: Dr Yerlan Aimuratov (Fesenkov Astrophysical Institute / al-Farabi Kazakh National University)

09:00 3D fundamental plane relation from the high-energy (Fermi-LAT) to the optical wavelengths

Speaker: Maria Dainotti (National Astronomical Observatory of Japan)

09:45 Cosmology with Gamma-Ray Bursts

Speaker: Lorenzo Amati (INAF - OAS Bologna)

amati_bego22_public.pdf

amati_bego22_public.pptx

10:30 Jet propagation, shock breakout and Cocoon emission

During my classes I will describe the main physical processes that govern the propagation of a relativistic jet in dense media and the cocoon that develops during this propagation. Then I will discuss the emission that is released during the shock breakout from the surface of the media and the following cocoon expansion.

Speaker: Ehud Nakar

11:15 Coffe break

11:30 Photospheric emission from relativistic cocoons

Speaker: Gregory Vereshchagin (ICRANet)

12:15 TBD

Speaker: Dafne Guetta

13:00 → 15:00 Lunch Break

15:00 → 17:45 Afternoon session

Convener: Yerlan Aimuratov (Fesenkov Astrophysical Institute / al-Farabi Kazakh National University)

15:00 TBD

Speaker: Tsvi Piran (The Hebrew University)

15:45 Cosmologies with Gravitational Anomalies and Axions: modified profiles of Gravitational Waves and warm dark matter properties

I discuss a string inspired model of cosmology, characterised by
gravitational anomalies and torsion, in the early stages,
which may provide a geometric origin of the entire dark sector of the
Universe, from a running-vacuum-model inflation to
axionic dark matter, the axion degrees of freedom being associated with
torsion. During inflation, the model may, under some circumstances, lead to
enhanced gravitational-wave perturbations and produced densities of
primordial black holes. At post inflationary (radiation) eras, in models
with massive right-handed neutrinos, one may have CPT Violating
Leptogenesis, as a result of Lorentz-Violating backgrounds of the
torsion-related axion fields, generated during inflation from
condensates of primordial gravitational waves that induce, in turn,
gravitational-anomaly condensates.
In the current era, such a model may contribute to observable in
principle deviations from Lambda-CDM, and alleviation of the observed
tensions in the cosmological data, provided, of course, the latter are
not due to astrophysical/statistical uncertainties. Non-perturbative
effects in such models (e.g. string instantons) may also generate
non-derivative couplings between axions and right-handed neutrinos,
which in turn may affect properties of warm dark matter in galactic
structure.

Speaker: Nikolaos Mavromatos (King's College London, Physics Department)

6th_Bego_rencontres_2022_Mavromatos_short_final.pdf

16:30 Coffee break

17:00 TBD

Speaker: Vahe Petrosian

Tuesday, 12 July

09:00 → 13:00 Morning session: Cocoon and BdHN Model

Convener: Liang Li (ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy)

09:00 Jet propagation, shock breakout and Cocoon emission

During my classes I will describe the main physical processes that govern the propagation of a relativistic jet in dense media and the cocoon that develops during this propagation. Then I will discuss the emission that is released during the shock breakout from the surface of the media and the following cocoon expansion.

Speaker: Ehud Nakar

09:45 TBD

Speaker: Tsvi Piran (The Hebrew University)

10:30 Multiscale gravitational astronomy in the Gaia era: general relativistic observables, models and tests for the Galaxy and its constituents. The Milky Way as Einstein’s paradigm.

Speaker: Mariateresa Crosta (INAF-OATo)

11:15 Coffee break

11:30 Slowly rotating thin discs around a central black hole as possible relativistic model of galaxy

Speaker: Petr Kotlarik

12:15 Relativistic models for galaxies

I will review exact solutions to Einstein’s field equations coupled to dust and discuss their application to galaxies’ dynamic.

Speaker: Astesiano Davide

13:00 → 15:00 Lunch Break

15:00 → 17:45 Afternoon session

Convener: Liang Li (ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy)

15:00 TBD

Speaker: Eleonora Troja (NASA/GSFC)

16:30 Coffee break

17:00 The physics of fast radio bursts

I will review the observational facts, the current theoretical framework, and the open questions in the studies of fast radio bursts, a type of mysterious transients prevailing in the radio sky.

Speaker: Bing Zhang (University of Nevada, Las Vegas)

Wednesday, 13 July

09:00 → 13:00 Morning session: Supernovae

Convener: Maria Dainotti (National Astronomical Observatory of Japan)

09:00 TBD

Speaker: Massimo Della Valle

09:45 Nature of the ultrarelativistic prompt emission phase of GRB 190114C and 180720B

Speaker: Rahim Moradi (ICRANet and ICRA-Sapienza)

10:30 The search for jet cocoons in broad line supernovae

Speaker: Luca Izzo (University of Copenhagen)

11:15 coffee break

11:30 ULTRASAT mission

ULTRASAT is a scientific satellite, that is planned to be launched to a geo-stationary orbit in Q2/Q3 2025. It will carry a telescope with an unprecedentedly large field of view (200 squared degrees) and UV (230-290nm) sensitivity. These unique properties will enable us to detect and systematically study transient astronomical events within an extra-Galactic volume, that is hundreds of time larger than that accessible to current observatories. ULTRASAT’s measurements will have a broad science impact across the fields of gravitational wave sources, supernovae, variable and flare stars, active galactic nuclei, tidal disruption events, compact objects, and galaxies. In this talk I will review ULTRASAT’s key science goals, its unique technical properties, and the project’s structure and status.

Speaker: Eli Wazman

12:15 Gamma-Ray Bursts Associated with Supernovae. Case studies: 190114C, 190829A, 130427A.

Speaker: Yerlan Aimuratov (Fesenkov Astrophysical Institute / al-Farabi Kazakh National University)

13:00 → 15:00 Lunch Break

15:00 → 17:45 Afternoon session

Convener: Maria Dainotti (National Astronomical Observatory of Japan)

15:45 SPH simulations of the Induced Gravitational Collapse

In the IGC paradigm, a carbon-oxygen star (COcore) collapses and explodes in a supernova (SN), the material ejected in the explosion is gravitational attracted by its companion, a neutron star (NS), taking place a hypercritical accretion process onto it. For compact systems, the accretion rate could be enough high to lead the NS to reach its critical mass, collapse in a black hole (BH) and emitted a gamma ray burst (GRB). With the aim to identify the separatrix of systems in which a BH is formed and characterize the observational signatures of each process, we have performed 3D-SPH numerical simulations of the SN expansion under the presence of the NS companion and explored a wide range of the initial parameter space.

I will outline the consequences in the observation of long gamma-ray bursts (GRBs).

Speaker: Laura Becerra Bayona

16:30 Coffee break

17:00 General discussion

Thursday, 14 July

09:00 → 13:00 Morning session: GRB 171205A and GRB 220101

Convener: Carlos Raúl Argüelles (Universidad Nacional de La Plata)

09:00 Binary-Driven Hypernovae: building blocks and future developments

Speaker: Jorge Armando Rueda Hernandez (ICRANet)

09:45 BdHN at large distances (2) spectral analysis

Speaker: Liang Li (ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy)

10:30 GRB 190829A - A Showcase of Binary Late Evolution

Speaker: Yu Wang (ICRANet, INAF)

11:15 Coffee break

11:30 General discussion

13:00 → 15:00 Lunch Break

15:00 → 17:45 Afternoon session

Convener: Carlos Raúl Argüelles (Universidad Nacional de La Plata)

15:45 TBD

Speaker: Chris Fryer (Los Alamos National Laboratory)

16:30 Coffe Break

17:00 Concluding remarks

Speakers: Jorge Armando Rueda Hernandez (ICRANet), Remo Ruffini (ICRANet, ICRA, INAF)