Talks


Argüelles, Carlos
Universidad Nacional de La Plata and CONICET
Argentina

Title: Fermionic dark matter in cosmology: from galactic halos to massive BHs
Authors: C. R. Argüelles, N. E. Mavromatos, J. A. Rueda, and R. Ruffini
Abstract: A new model for the distribution of dark matter (DM) in galaxies has been recently introduced, the Ruffini-Argüelles-Rueda (RAR) model, based on a self-gravitating system of massive fermions ('inos') at finite temperatures. The RAR model, for fermion masses in the range 10^{1-2} keV, successfully describes the DM halos in galaxies, and predicts the existence of a denser quantum core towards the center of each configuration, which may work as an alternative to massive BHs. I will discuss the state of the art of these kind of models covering: i- the possibility to include self-interactions among inos starting from a minimally extended beyond SM Lagrangian; ii- its ability to provide an alternative to the massive BHs in SgrA* as well as in more massive elliptical galaxies; iii - the agreement with observed Universal correlations involving DM halos as well as central dark massive comapct objects for a wide range of galaxy types; iv) the situation with respect to the large/small scale structure predictions made by standard cosmological N-body simulations of cold and warm DM models.

Arsioli, Bruno Sversut
ASDC - ASI & La Sapienza
Italy

Title: The isotropic gamma-ray background: Contribution from HSP blazars to the diffuse component

Auyeskhan, Seiytkalikyzy
al-Farabi Kazakh National University
Kazakhstan
Title: The perturbation theory of two rotational bodies in theory of General Relativity

Baktiyarova, Arailym
Al-Farabi Kazakh National University
Kazakhstan
Titile: Collision of processes in dense plasma

Becerra Bayona, Laura Marcela
Sapienza University of Rome and ICRANet
Italy

Title: On the induced gravitational collapse scenario of gamma-ray bursts associated with supernovae.
Authors: Laura M. Becerra, Carlo L. Bianco, Chris L. Fryer, Jorge A. Rueda and Remo Ruffini.
Abstract: We analyze the induced gravitational collapse scenario of gamma-ray bursts (GRBs) associated with supernovae. We present numerical simulations of the explosion of the carbon-oxygen (CO) core as type Ib/c supernova in presence of a close neutron-star companion. We give details of the hypercritical accretion process triggered by the supernova ejecta onto the neutron-star as a function of the binary parameters and discuss the observables during the different phases of the process starting from the early accretion, to the collapse of the neutron-star, to the interaction of the radiation of the above process with the supernova.

Title: The spin evolution of fast rotating, magnetized super-Chandraskehar white dwarfs in the aftermath of white dwarfs mergers.
Authors: Laura M. Becerra, Jorge A. Rueda, Pablo Loren-Aguilar, Enrique Garcia-Berro
Abstract: The existing simulations of the coalescence of binary white dwarfs show that the final result of the coalescence consists of a central remnant made of the undisrupted primary star and a hot, convective corona made of about half of the mass of the disrupted secondary. This central remnant is surrounded by a heavy Keplerian disk, made of the rest of the mass of the disrupted secondary, since little mass is ejected from the system during the merger episode. Here we compute the post-merger evolution of a super-Chandrasekhar magnetized white dwarf taking into account all the relevant physical processes. These include magnetic torques acting on the star, accretion from the Keplerian disk, and the threading of the magnetic field lines through the disk.

Belczynski, Chris
Astronomical Observatory, Warsaw University
Poland
Title: Massive Stellar Black Hole Binaries and Gravitational Waves

Belinski, Vladimir
ICRANet
Italy
Title: Integrable SUGRA

Bianco, Carlo Luciano
ICRANet
Italy


Boshkayev, Kuantay
Al-Farabi Kazakh National University
Kazakhstan

Title: I-Love-Q relation in White Dwarfs

Caceres Uribe, Diego Leonardo
Sapienza Università di Roma
Italy

Title: On the spin-down of AXP's and SGR's as pulsar White Dwarfs
Abstract: Anomalous X-ray pulsars (AXPs) and Soft Gamma-ray repeaters (SGRs) are considered as highly magnetized rapidly rotating white dwarfs, instead of the traditional magnetar model, which model them as highly magnetized neutron stars. In this model the X-ray emission is rotationally powered, like in the traditional model for pulsars. We consider the two main traditional magnetospheric models for pulsars (outer-gap and polar cap models) applied to rapidly rotating white dwarfs to explain the X-ray emission of AXPs and SGRs.

Chieffi, Alessandro
Istituto di Astrofisica e Planetologia Spaziali dell'INAF
Italy
Title: The physical properties of a massive star at the beginning of the core collapse as a function of mass, metallicity and initial rotational velocity.
Abstract: I will briefly review how the mantle of a massive star depends in M, Z and Vini in order to understand which, if any, range of models is suitable to become a Type Ic Supernova. Moreover I will show our current estimate of the Mrem-Ekin as a function, again, of M,Z and Vini.

Cipolletta, Federico
Istituto per le Applicazioni del Calcolo "Mauro Picone", CNR
Italy

Title: Structure of relativistic, rapidly rotating Neutron Stars: interior and exterior spacetime
Authors: F. Cipolletta, C. Cherubini, S. Filippi, J. Rueda and R. Ruffini
Abstract: Equilibrium configurations of relativistic and rapidly rotating Neutron Stars (NSs) are obtained, thank to a public domain C code (RNS). From these one may reconstruct the structure of spacetime interior to such compact objects, arranging their physical properties and conditions to obtain secular axisymmetric stability. In addition, it is possible to give information about exterior spacetime, for example estimating the mass quadrupole and studying orbits of particles around the NS. This complete treatment allows several applications, e. g. to have a fit for angular momentum of particles around a rotating NS within a hypercritical accretion scenario in a binary system which may result in a hypernovae explosion.

Della Valle, Massimo
Capodimonte Observatory; INAF - Naples & ICRANet, Pesacara
Italy

TBD

Even, Wesley
Los Alamos National Laboratory
USA
Title: Modeling Light Curves From Transients
Author: Wesley Even
With the current generation of survey telescopes beginning to come online, the number of observed supernovae has exploded in recent years. The new data provided by these observations creates opportunities and challenges for understanding the theory behind supernovae. I will provide an overview of the Los Alamos toolkit for generating simulated electromagnetic observations from supernovae. This will include a detailed description of the computational multi-physics methods and our collaborative efforts for generating community databases of the models. I will also describe our efforts to expand our light curve capabilities beyond supernovae to merging compact objects.

Fisher, Robert
University of Massachusetts Dartmouth
USA

Title: Single- and Double-Degenerate Type Ia and Type Iax Supernovae
Abstract: The debate surrounding the nature of the progenitors of Type Ia supernovae rages on, the past several years have seen remarkable progress on this long-standing and significant topic. A number of lines of evidence in normal SNe Ia -- ranging from the delay time distribution, to the absence of companions in pre-explosion data, to the absence of hydrogen, radio and X-ray signatures, and ex-companions in post-explosion data -- all point to sub-Chandrasekhar progenitors through the double-degenerate or possibly the double-detonation channels. At the same time, additional recent observational evidence, including stable iron peak element abundances in the supernova remnant 3C 397, and the signature of shocked companions in iPTF14atg and 2012cg, also point towards the co-existence of single-degenerate SNe Ia as the progenitors of at least some SNe Ia. Yet other observations have characterized underluminous, failed SNe Ia events, often referred to as SNe Iax, and demonstrated that these occur relatively frequently. Thus there is a growing recognition that there is a diversity of Type Ia supernova progenitors, leading to a diverse set of outcomes. This growing recognition also points to key challenges, including: What is the predicted range of outcomes for each progenitor channel? What observational signatures precisely link a given SN Ia event to a specific progenitor? In my talk, I will present recent theoretical work done by my group and collaborators on both the single and double-degenerate models for Type Ia supernovae which addresses these questions. I will present recent three-dimensional numerical simulations of double-degenerate mergers which yield SNe Ia through a novel new spiral disk mechanism, and show that their light curves and spectra are consistent with slowly-declining events like SN 2001ay. I will also present other very new work we are pursuing on the role of thin layers of helium in igniting sub-Chandrasekhar white dwarfs in the double-degenerate channel. Additionally, I will also show that hybrid merging O/Ne and C/O white dwarf systems robustly lead to failed subluminous SNe Ia. Lastly, I will present work on the supernova remnant 3C 397. I will demonstrate that the observed stable iron-peak elemental abundances in 3C 397 are consistent with state-of-the-art multi-dimensional models of Chandrasekhar-mass SNe Ia, and discuss the implications for the mass-donating non-degenerate companion.

Garcia-Berro, Enrique
Universitat Politècnica de Catalunya, Departament de Física
Spain

Title: White dwarf collisions: a new pathway to type Ia supernovae
Author: Enrique García-Berro, Pablo Lorén-Aguilar & Noam Soker
Abstract: Thermonuclear supernovae, also known as Type Ia supernovae (SNe Ia), are the result of the explosion of carbon-oxygen white dwarfs. Given that they are one of the most powerful events in the universe, they can be seen at very large distances. Moreover, the homogeneity of their observed light curves allows us to use them as standardizable cosmological candles. However, despite their intrinsic importance and their extraordinary relevance, the nature of the progenitor systems that give rise to SNe Ia has not been hitherto elucidated. Possible scenarios leading to a SN Ia outburst include the dynamical merger of a double white dwarf binary system (the so-called DD scenario), the merger of a non-degenerate companion with a white dwarf (the SD scenario), the merger of an AGB star and a white dwarf (known as the CD scenario), and the collision of two white dwarfs in a dense stellar environment. There exists observational evidence disfavoring the SD channel, although the rest of the theoretical paradigms are not exempt of problems either. In this talk I will discuss two alternative scenarios: the CD and the collisional scenarios.

Title: The core degenerate scenario: an alternative pathway to SNIa

Gómez Díaz, Luis Gabriel
University of Rome "La Sapienza" and ICRANet
Italy

Title: Fermionic Dark Matter Distribution As a Lens Model of Galaxies: Inquiring About the Gravitational Lensing Properties Near the Galactic Center
Abstract: We describe the gravitational lensing properties of a novel Dark Matter (DM) fermionic configuration in Milky Way-like galaxies. We focus particularly on the effect of the DM halo in the lensing properties alone, ignoring the contribution of the bulge and disk to the net lensing effect, where the latter component is remarkably significant. Nevertheless, we take into account the contribution of the DM central core, predicted in our model as a different interpretation of the central compact object in Sgr A*, to the gravitational lensing effect. As a result, we estimate the scale radius $\sim 10^{-4}$ pc at which strong lensing effects start to be important into the galaxy so that relativistic effects must be considered. Hence, we discuss a possible strong lensing effect of the fermionic DM central core as in the case of the Schwarzschild Black Hole (BH) in Sgr A*. Even though the DM central core may not account for these relativistic effects, as the formation of the photon sphere predicted by the BH prescription, it could lead us to infer about the nature of compact objects at the center of other galaxies. Furthermore, we highlight that the deflection angle differences produced by DM density profiles in the galactic halo together with rotation curve data, could help us to discriminate between different DM models.

Harutyunyan, Vahagn
Uniroma1, INAF-OAC
Italy

Title: SN rates from SUDARE survey
Abstract: The nature of SN explosions and their correct progenitor models, as well as whether they evolve with redshift has still unanswered questions. Measuring rates of SNe could help us to gain clues on those issues. With this aim the Supernova Diversity and Rate Evolution (SUDARE) is conducted which is currently ongoing survey on VST at ESO. The main goal of SUDARE is to measure the rate of different SN types in the redshift range of $0.2

Jones, Samuel
Heidelberg Institute for Theoretical Studies
Germany

Title: Simulating the lives and deaths of 8--10 solar-mass stars
Co-authors: F. K. Rö;pke, R. Pakmor, I. R. Seitenzahl, S. T. Ohlmann, P. V. F. Edelmann, R. Andrassy, S. Sandalski, A. Davis, P. Woodward, F. Herwig
Abstract: The progenitor stars of supernovae (SNe) are in many aspects still poorly understood. Stellar evolution (SE) codes are an invaluable tool with which to study the long term evolution of supernova progenitors, however they necessarily rely on the assumption of spherical symmetry (1D) and approximations for dynamical mixing processes (such as mixing length theory; MLT). Although such assumptions and approximations limit the predictive power of SE codes, they can be informed and supplemented by multidimensional hydrodynamic simulations. The fate of light massive stars (with 8 – 10 solar masses) that sit on a knife-edge between white dwarf (WD) and neutron star (NS) production is arguably the poorest understood of all. If these stars can indeed explode, they are said to be either electron-capture supernovae (ECSNe) or the accretion-induced collapse (AIC) of oxygen-neon (ONe) WDs. ECSNe and AIC have long been thought to be core-collapse supernovae in which a NS is formed. I will present new research which, through multidimensional hydrodynamic simulations, suggests that an ECSN might be quite a different phenomenon in which a thermonuclear explosion leads to partial disruption of the star, thereby avoiding the formation of a NS completely. This result is not, however, without uncertainty. Predictions for the initial mass and statistical significance of ECSNe and AIC made using SE codes are very sensitive to the way in which convection and convective boundary mixing is approximated. I will present high resolution simulations of convective oxygen shell burning in a massive star and show that convective transport of material and the erosion of the stable layer above the convective boundary by entrainment processes can be relatively well approximated in 1D SE codes with a simple modification to MLT and an exponentially decaying diffusion coefficient.

Kalymova, Zhanerke
Al-Farabi Kazakh National University
Kazakhstan
Title: Investigation of hot white dwarfs in general theory of relativity and comparison of theoretical results with observational data

Karlica, Mile
Università La Sapienza di Roma/ICRANet
Italy

Title: Electron Synchrotron Emission in GRB-SN Interaction: First Results

Kazhykenov, Shalkar
Al-Farabi Kazakh National University
Kazakhstan
Title: Research halo-structure of light atomic nuclei.

Kenzhebayeva, Saltanat
Al-Farabi Kazakh National University
Kazakhstan
Title: Investigation of dynamic stable states of multi particle systems with controlled boundary conditions

Kovacevic, Milos
University of Sapienza, Rome
Italy

Title: Thermal Emission in Gamma-ray Burst X-ray Afterglow
Abstract: Thanks to the Swift spacecraft and X-Ray Telescope (XRT) instrument on-board we have very detailed look at afterglow of Gamma-ray bursts (GRBs). In this talk approach to spectral analysis of XRT data in order to search for thermal emission will be presented. Results point towards two group of thermal emitters. These two groups correspond to two groups of GRBs based on their isotropic energy (Eiso) - one with Eiso grater then 1e52 erg and other with Eiso around 1e51 erg. This can be explained within Induced Gravitational Collapse model.

Krut, Andreas
ICRANet
Italy

Title: Dark Matter and Galactic Structures
Abstract: We consider a self-gravitating system composed of massive fermions in spherical symmetry. The model in this case is built in the more general possible way compared to Newtonian approaches. This is, we solve the Einstein equation for a thermal and semi-degenerate fermionic gas considered as a perfect fluid in hydrostatic equilibrium including relativistic effects (Ruffini et al. 2015). Additionally, we consider evaporation what causes a bounded mass distribution. No additional interaction is assumed for the fermions besides their fulfilling of quantum statistics and the relativistic gravitational equation. Within this more general approach a new family of density profiles arises which explains dark matter halo constraints of the Galaxy and provides at the same time an alternative to the central black hole scenario.

Malheiro, Manuel
Aeronautics Institute of Technology, ITA, Departament of Physics
Brazil
Title: SGRs/AXPs: source of energy and radio emission

Melon Fuksman, Julio David
ICRANet & Sapienza Università di Roma
Italy
Title: Numerical methods for relativistic plasma physics

Mirzoyan, Razmik
Max-Planck-Institute for Physics
Germany
Title: Crab Pulsar and the Crab Nebula, Measured With MAGIC From ~25 GeV Till ~80 TeV
Author: Razmik Mirzoyan for the MAGIC Collaboration
Abstract: The Crab pulsar is a young neutron star (NS) with a rotational period of 33 ms. Together with the Crab nebula it is the remnant of the supernova explosion SN1054. Crab is the most powerful pulsar in our galaxy. It is detected at all wavelengths from radio up to gamma rays, and is one of the brightest at high energies. The pulsar emission profile is characterized by the two pulses P1 and P2 separated by 0.4 in phase and locked in phase at all energies and the bridge emission between the two pulses. Until ten years ago the accepted point of view was that there shall be no emission above the cut-off energy ~6 GeV. Nevertheless, pulsed gamma rays with energy ≥ 25 GeV have been measured by MAGIC in 2008. In the following years MAGIC succeeded to measure the bridge emission and the pulsed emission at significantly higher energies, the P2 extending till ~1.2 TeV with no visible cutoff. Note please that already at ~100 GeV the pulsed emission is about two orders of magnitude lower than that of the nebula, the standard calibration source of very high energy gamma-ray telescopes. MAGIC measured the DC-emission of the nebula till the energy ~80 TeV. In our presentation we want to dwell on the main features of Crab, which we systematically study and update, trying to put together parts of this complex puzzle.

Moradi, Rahim
ICRANet and Sapienza University
Italy

Title: Plasma accretion to Kerr Black hole
Abstract: In this work we have studied the plasma accretion to Kerr black hole and possible ways to extract electromagnetic energy from it, also the possibility of using this model to describe the engine for astrophysical phenomena such GRB and AGN has been proposed.

Myrzabayev, Abylay
Al-Farabi Kazakh National University
Kazakhstan
Title: Boson theory of the collective state of the deformed thorium isotopes

Muccino, Marco
Dipartimento di Fisica and ICRA, Sapienza Università di Roma
Italy

Title: Classification of long and short bursts and their rate of occurrence

Title: GRB 090510: a S-GRB from a binary neutron star coalescing into a Kerr black hole

Naizabekov, Berik
Al-Farabi Kazakh National University
Kazakhstan
Title: The research of structural and electronic properties of crystals within the density functional theory

Nazerke, Abdualiyeva
al-Farabi Kazakh National University
Kazakhstan
Title: Superposition of relativistic effects in the Fock metric

Pisani, Giovanni Battista
Università La Sapienza di Roma and ICRANet
Italy


Rodriguez Ruiz, Jose Fernando
Sapienza University of Rome
Italy

Title: A simple approach to GW150914
Authors: Jose F. Rodriguez, Jorge Rueda, R. Ruffini
Abstract: We analyze the event GW 150914 announced by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) as the gravitational-wave emission of a black-hole binary merger. We show that the parameters of the coalescing system and of the newly formed Kerr black-hole can be extracted from basic results of the gravitational-wave emission during the inspiraling and merger phases without sophisticate numerical simulations. Our estimates are based formulas describing two different regimes: 1) the binary inspiraling analysis 2) the plunge of a particle test particle into a black-hole.

Rueda Hernandez, Jorge Armando
ICRANet
Italy


Sahakyan, Narek
ICRANet-Armenia
Armenia

Title: Gamma-ray emission from non-blazar AGNs
Abstract: The gamma-ray detection by Fermi-LAT from non blazar active galactic nuclei shows that these are different and potentially very interesting classes of gamma-ray emitters. This provides an alternative approach for studying high energy emission processes compared to blazars where the emission is strongly Doppler boosted. Up to now there are 32 non-blazar AGNs detected in the gamma-ray band which are included in the third catalog of AGNs detected by Fermi LAT. I will present a detailed investigation of the gamma-ray emission from non-blazar AGNs based on seven years of Fermi LAT data.The accumulation of a larger data set allows detailed temporal analysis in short and long time scales as well as to study the spectrum with better statistics at energies above several GeV. Also the possible origin of observed gamma-rays will be discussed considering both compact and extended regions.

Shakeri, Soroush
IUT
Iran

Sigismondi, Costantino
ICRANet
Italy

Title: Riflessioni sulle esplosioni in astrofisica e fisica nucleare, reflexions on explosions in astrophysics and nuclear physics
Author: Costantino Sigismondi, ICRANet/Sapienza e IIS Caffè, Roma
Abstract: In prima approssimazione un'esplosione è un fenomeno di rilascio di energia in un tempo molto più breve di quanto è stato necessario per accumularla. Secondo questo criterio anche il rilascio in qualche secolo nell'ambiente di materiale con tempi scala di diffusione o percolazione di migliaia di anni è un'esplosione. Nel ciclo di Otto del motore a scoppio c'è un'esplosione, come nella bomba nucleare, ma i tempi scala e l'energetica di questi fenomeni sono diversi. Con la funzione esponenziale decrescente si rappresentano i fenomeni di esplosione, ma i tempi caratteristici e le modulazioni dell'andamento sono specifici di ogni caso. Alla luce di questo concetto si esaminano anche i casi di Novae, Supernovae, Hypernovae, Gamma-Ray Bursts e coalescenza di due buchi neri, che avrebbe trasformato in onde gravitazionali 3 Masse solari in 0.2 secondi.

Stahl, Clément
ICRANet
Italy

Title: interacting dark energy
Abstract: We investigate a cosmological model of interacting dark matter and dark energy. This model has two extra parameters $\delta_g$ and $\delta_{\Lambda}$ which corresponds to the rate of conversion of dark matter into dark energy. We perform a $\chi^2$ fit with the supernovae IA data to constrain this new model and find that the interacting model obtains a better $\chi^2$ than the standard cosmological model. We then explore the range of parameter of the model which gives a better $\chi^2$ than the standard cosmological model. Our conclusion is that the class of model, we investigated, provided once again a decent alternative to the $\Lambda$CDM model.

Utepova, Daniya
Al-Farabi Kazakh National University
Kazakhstan
Title: Description of the fluctuations in financial markets help with Econophysics models

Vereshchagin, Gregory
ICRANet
Italy

Title: Cosmic absorption of high energy particles

Wiggins, Brandon
Los Alamos National Laboratory
USA
Title: Modelling Dredge-Up in Double White Dwarf Mergers
Authors: Brandon K. Wiggins, Wesley P. Even, Jan Staff, Chris L. Fryer
Abstract: Mergers involving carbon-oxygen and helium white dwarf stars have been suggested as a possible mechanism for the formation of R Coronae Borealis stars. This formation process is sensitive to the amount of mixing during the merger as the accretion process must not dredge up large amounts of the accreting star into the remnant's envelope. In this presentation, I will summarize our efforts to model white dwarf mergers with SNSPH, a particle-hydro code developed by Chris Fryer. We provide a brief discussion on our simulation tools and methodology and present our predictions for mixing during the merger process. We compare our results with similar grid-based calculations and discuss implications for double white dwarf mergers in general.

Xue, She-Sheng
ICRANet
Italy

Title: Electric Charge distribution around Ker black hole due to neutral plasma accretion

Young, Patrick
School of Earth and Space Exploration, Arizona State University
USA
Title: Supernova Synthesis and Structure from Explosion to Remnant
Authors: Patrick A. Young, Carola I. Ellinger, Chris L. Fryer, Gregory Vance
Abstract: We present 3D simulations following the evolution of supernova structures from their inception in the stellar core through the development of a supernova remnant into the Sedov phase. Combined with detailed nucleosynthesis calculations, we produce nucleosynthetic maps of the mixing between stellar and interstellar matter as the supernova evolves into a young supernova remnant. Our set of simulations use multiple progenitors and structures of the circumstellar environment. These calculations demonstrate the role that supernova instabilities (the instabilities that develop as the shock drive through the star) play in defining the structure and long-term development of instabilities in supernova remnants and distribution of newly synthesized isotopes into the local interstellar medium.

Zhami, Bakytzhan
Al-Farabi Kazakh National University
Kazakhstan
Title: Hot White Dwarf Stars