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ICRANet Newsletter

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ICRANet Newsletter
May - June - July 2018

1. The paper by C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini, "Novel constraints on fermionic dark matter from galactic observables I: The Milky Way" is accepted for publication in Physics of the Dark Universe on 12 July 2018
2. The Fifteenth Marcel Grossmann Meeting (MG15) – Rome, 1 – 7 July 2018
3. Professor Ruffini visit to Albania, 23 – 24 May 2018
4. Professor Ruffini nominated as Member of the Horizon 2020 Advisory Group for the Marie Sklodowska-Curie actions on skills, training and career development (MSCA) programme – Bruxelles, 28 June 2018
5. Collaboration Agreement between Sun Yat-Sen University and ICRANet, 4 July 2018
6. Closing Ceremony of the project "Del Talento e della curiosità. Quando l'aquila e il passero volano insieme"- Presentation of the results, 4 May 2018
7. Technical-scientific report of the project "Del Talento e della curiosità. Quando l'aquila e il passero volano insieme" (ICRA, ICRANET, Fondazione Marco Besso, ECIPA)
8. Congratulations to ICRANet Faculty Professor Gregory Vereshaghin, awarded of the Doctor of Sciences (DSc) degree in theoretical physics, 13 June 2018
9. Seminars at ICRANet center in Pescara
10. Scientific visits to ICRANet
11. Recent publications

1. The paper by C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini, “Novel constraints on fermionic dark matter from galactic observables I: The Milky Way” is accepted for publication in Physics of the Dark Universe on 12 July 2018

Since near a century already, Astronomers ans Asrtrophysists have been gathering and analyzing data coming from galaxies, either small, or large ellipticals, or clumped in large clusters; to realize that about the 85% of the matter content of the Universe cannot be made of any of the building blocks we know (such as electrons, protons, neutrons, or its combinations). They came to the conclusion that the gravity exerted by all these possible known forms of matter, as combined in stars, gas or dust, is not enough to explain the observed stability and the kinematical properties in galaxies: an extra matter content was needed, called dark matter (DM).
A consensus has been reached within the scientific community about the nature of the DM, pointing towards an unknown fundamental particle created at the dawn of times. These particles would have started to gather together due to its own self-gravity into many different clumps of matter, dubbed as DM halos. Such pristine agglomerations are spherical configurations which constitute the progenitors of the galaxies we see today, with the halo component spreading typically about ten times the extension of the bright and normal matter composing the disk (as in the case of our home, the Milky Way). An important open question in the field, is precisely how this DM is distributed along a given galaxy, as well as the exact nature of the particle constituting the DM. The traditional approach to tackle this issue is given in terms of big numerical simulations involving a large amount of classical point masses. While such simulations provide the needed dark mass to account for the rotation curve of a galaxy, it has several problems on smaller scales below 10 kpc when confronted with observations.


For the first time, the authors in [1] have presented an alternative approach to this problem, which allows to consider the quantum nature of the dark constituents as well as the particle mass dependence, directly in the DM profiles. Such a model consists in solving the equations of a self-gravitating gas of elementary neutral fermions at finite temperature allowing for escape of particle effects. The theory has been recently applied to the case of our own Galaxy, which is certainly the best benchmark to test it, given the vast and precise amount of data available to the date. For particle masses in the range of few 10 to 100 keV (see Figure), the solutions obtained by the authors provide the right description for the rotation curve of the Galactic halo, and predict at the same time, a dense and compact core of quantum nature harbored at the center. The key novelty of such dark matter core, is the possibility to explain the dynamics of the closest star orbiting around the SgrA* Galaxy center, without the need to introduce a super massive black hole (BH).
Read more: https://doi.org/10.1016/j.dark.2018.07.002

2. The Fifteenth Marcel Grossmann Meeting (MG15) – Rome, 1 – 7 July 2018

The Fifteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories (MG15) took place at "Sapienza" University in Rome – Italy, from July 1 to 7, 2018. The meeting exceeded every expectation and confirmed once again its world leading role in the field of Relativistic Astrophysics, developed in the years since 1985 by ICRA at Sapienza University, and, in the most recent years, thanks to the collaboration with ICRANet center in Pescara.

Fig. 1 - MG15 group photo in Aula Magna, Sapienza University, Rome

More than 800 participants from 70 different countries in the world, joined the conference and presented the most relevant recent results on the understanding of the Universe, achieved thanks to Albert Einstein’s equations of general relativity. Thanks to the financial support provided by IUPAP, ICTP and ESA, a lot of scientists from developing countries had also the possibility to attend the conference.
Registration started since Sunday, July 1, from 10:00 am to 7:00 pm and the official opening of the meeting took place on Monday morning, (July 2), at the presence of Professor Eugenio Gaudio, Rector of Sapienza University with the Marcel Grossmann Awards’ ceremony, see: https://youtu.be/Mz5ZY0WzTDQ

This year, the Institutional Awards went to:
* The Planck Scientific Collaboration (ESA), presented to Jean-Loup Puget, the Principal Investigator of the High Frequency Instrument (HFI) - "for obtaining important constraints on the models of inflationary stage of the Universe and level of primordial non-Gaussianity; measuring with unprecedented sensitivity gravitational lensing of Cosmic Microwave Background fluctuations by large-scale structure of the Universe and corresponding B-polarization of CMB, the imprint on the CMB of hot gas in galaxy clusters; getting unique information about the time of reionization of our Universe and distribution and properties of the dust and magnetic fields in our Galaxy".
* Hansen Experimental Physics Laboratory At Stanford University, presented to Research Professor Leo Hollberg, HEPL Assistant Director - "to HEPL for having developed interdepartmental activities at Stanford University at the frontier of fundamental physics, astrophysics and technology".

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Fig.2 – MG15 Awards Ceremony From left to right: Prof. Leo Hollberg, Prof. Rashid Sunyaev, Prof. Shing-Tung Yau, Prof. Remo Ruffini, Rector Eugenio Gaudio, Prof. Roy Kerr, Prof. Lyman Page, Prof Jean-Loup Puget and Prof. Elia Battistelli. Fig. 3 – Prof Jean-Loup Puget (ESA) receiving the MG15 institutional award. Fig. 4 – Prof. Leo Hollberg (HEPL) receiving the MG15 institutional award.

The Individual Awards went to:
* Lyman Page "for his collaboration with David Wilkinson in realizing the NASA Explorer WMAP mission and as founding director of the Atacama Cosmology Telescope".
* Rashid Alievich Sunyaev "for the development of theoretical tools in the scrutinising, through the CMB, of the first observable electromagnetic appearance of our Universe".
* Shing-Tung Yau "for the proof of the positivity of total mass in the theory of general relativity and perfecting as well the concept of quasi-local mass, for his proof of the Calabi conjecture, for his continuous inspiring role in the study of black holes physics".
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Fig 5, 6, 7 – From left to right: Prof. Lyman Page, Prof. Rashid Sunyaev and Prof. Shing-Tung Yau receiving the MG15 individual awards.

During this six day conference, a variety of topics were discussed in the morning plenary sessions, beginning with Mathematical and general relativity topics on Monday, Kilonovae and Gravitational Waves on Tuesday, Future Precision Tests of GR on Wednesday, GRBs and CMB on Thursday, Multimessanger Astrophysics on Friday and The Frontiers on Saturday.
Up to 26 parallel sessions per days took place in every afternoon sessions, within the University Campus and the nearby CNR building, covering the following topics: Accretion, Alternative Theories, Black Holes, Binaries, Boson Stars, Cosmic Microwave, Cosmic Strings, Dark Energy And Large Scale Structure, Dark Matter, Education, Early Universe, Gamma Ray Bursts, Gravitational Waves, High Energy, History Of Relativity, Neutron Stars, Precision Tests, Quantum Gravity, Strong Field and White Dwarfs.
There were several public lectures delivered in the evening sessions, namely by Jeremiah Ostriker, Malcolm Longair, Marc Henneaux, Jean-Loup Puget, Lyman Page and Anne Archibald.
Several social events were organized for all the participants of the meeting: on Tuesday evening, eminent Professors and researches from Sun Yat-Sen University (China) presented their Institute and celebrated the signature of the cooperation agreement with ICRANet, by organizing the interesting event “SYSU Connection reception”. On Wednesday evening there was the official MG15 banquet, held at Palazzo Colonna, an ancient palace in the core of Rome, and this was the occasion for Ms Claudia Graf-Grossmann (niece of Marcel Grossmann), to present to the auditors the biography of her grandfather, whose preface was edited thanks to the collaboration with Professor Remo Ruffini, Director of ICRANet. The participants had also the possibility, on the same day, to visit Galleria Colonna, the private art collection of the Palace.

Several publishing companies were present along all the meeting in a space devoted to exhibitions (namely Cambridge University Press, IOP Publishing, Universe and Springer Nature) and also the Chinese state television was present to film and document the event, see: https://youtu.be/KbTgZuPEGgc and https://youtu.be/cbYbSn2BoFE
Currently, ICRA and ICRANet are taking care of the MG15 Proceedings, which will consist in open access e-book proceedings and will be published by World Scientific, Singapore, in 2019.

Here are some useful links to consult:
* Interview with Prof. Remo Ruffini: https://www.youtube.com/watch?v=i24U7SGoVAc&feature=youtu.be;
* MG15 website: http://www.icra.it/mg/mg15

3. Professor Ruffini visit to Albania, 23 – 24 May 2018

On 23 and 24 May 2018, Professor Ruffini, thanks to the collaboration of Professor Mimoza Hafizi, flew to Albania to met Prof. Dr. Mynyr Koni, Rector of the University of Tirana: this meeting was the opportunity for them to discuss about the possibility for that institute, to become full Member of the IRAP-PhD with all the rights and privileges envisaged by the IRAP-PhD Statute. The visit was a follow up of the unanimously proposal of the University of Tirana as potential member of the joint doctorate, as emerged in the meeting of the IRAP-PhD Faculty, held on 30 April 2018.

4. Professor Ruffini appointed as Member of the Horizon 2020 Advisory Group for the Marie Sklodowska-Curie actions on skills, training and career development (MSCA) programme – Bruxelles, 28 June 2018


Professor Ruffini was officially appointed as member of the “Horizon 2020 Advisory Group for the Marie Sklodowska-Curie actions on skills, training and career development (MSCA) programme” for the period 2018-2020 (3rd mandate). The European Commission was renewing the membership of its Advisory Groups which provide external high-quality input to help inform, assess, enrich and keep up-to-date its reflections and ideas for the monitoring and development of the Horizon 2020 Work Programme and Professor Ruffini was selected for his specific knowledge, skills and experience in the field of science. His biography was also inserted in the Who’s Who booklet of the group.
The appointment took place on the occasion of the 12th Meeting of the MSCA Advisory Group, held in Brussels on 28 June 2018: this was the first meeting of the AG under its third configuration for Horizon 2020.
The MSCA financially support researchers at all stages of their careers, irrespective of nationalities and disciplines. Funding may be attributed to individual researchers, networks, staff exchange programmes and doctoral/postdoctoral programmes. In addition to providing research funding, MSCA enable scientists to gain international, inter-sectoral and interdisciplinary experience and to complete their scientific training with transferable competences that will enhance their employability and career prospects. For more information about the MSCA Advisory Group, see the link: http://ec.europa.eu/research/mariecurieactions/

5. Collaboration Agreement between Sun Yat-Sen University and ICRANet, 4 July 2018

On the 4 July 2018, ICRANet signed a cooperation agreement with the Sun Yat-Sen University of Guangzhou – China, which will be valid for 5 years. The document was signed by Prof. Luo Jun, President of the Sun Yat-Sen University, and Prof. Ruffini, Director of ICRANet, during Professor Luo participation as a plenary speaker to the 15th Marcel Grossmann Meeting, held in Rome from 1 to 7 July 2018. Eminent Professors and researches from this University enjoyed MG15, and took this opportunity to present their Institute and celebrate the signature of the cooperation agreement with ICRANet, by organizing the interesting event “SYSU Connection reception” in University of Rome La Sapienza.
Fig. 8 - Prof. Luo Jun, President of the Sun Yat-Sen University, and Prof. Ruffini, Director of ICRANet, after the signing the Collaboration Agreement.

The main joint activities to be developed under the framework of this agreement include: the promotion of theoretical and observational activities within the field of Relativistic Astrophysics; the institutional exchange of faculty members, researchers, post-doctorate fellows and students; the promotion of technological developments; the development of Data Centers for Astrophysical data in all wavebands; the organization of training and teaching courses, seminars, conferences, workshops or short courses, and the development of inter-institutional research areas associated to local graduate programs; and joint publications.
For the text of the agreement, see: http://www.icranet.org/documents/agreementICRANet-SunYatSenUniversity.pdf
For more information about Prof. Luo participation to MG15: http://www.sysu.edu.cn/2012/en/news/news01/32725.htm

6. Closing Ceremony of the project "Del Talento e della curiosità. Quando l'aquila e il passero volano insieme"- Presentation of the results, 4 May 2018

Official program of the closing ceremony event - ICRANet, 4 May 2018

On Friday 4 May 2018, ICRANet center in Pescara hosted the closing ceremony of the project supported by the Italian Ministry of Education, University and Research (MIUR) “Del Talento e della curiosità. Quando l’aquila e il passero volano insieme” (“Of Talent and Curiosity. When the eagle and the sparrow fly together”), in collaboration with the Besso Foundation, ICRA and ECIPA. The event was also attended by more than 50 students from the classes 4D and 4I of “Liceo scientifico Galileo Galilei” of Pescara, under the supervision of Professors Gabriele Fraternali and Tiziana Pompa. This event concluded a series of other initiatives developed since last year in the framework of this project, and was devoted to present the attended results and the possible future perspectives. The referents of the event were Professor Remo Ruffini, director of ICRANet and Mr. Marco Trisi, Director of ECIPA. After a press conference, the two referents resumed to the highlight of the past events occurred in the framework of the project, and showed them some videos realized on those occasions. Namely, the videos concerned the two exhibitionsF on “Einstein, Fermi and Heisenberg and the birth of Relativistic Astrophysics” and on “ICRANet and China” held in Besso Foundation (Rome) from 12 December 2017 to 12 January 2018 and the three seminars organized in parallel on 12 December 2017, 8 and 12 January 2018. At the end of this presentations, the students took the floor to present the scientific instruments they produced on their own in the framework of this project.

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Fig. 9, 10, 11 - Students from the classes 4D and 4I of "Liceo scientifico Galileo Galilei" of Pescara, attending the event at ICRANet center, 4 May 2018.

To conclude the event, Professor Zurab Berezhiani from the Department of Physical and Chemical Sciences of University of L'Aquila, gave an important seminar titled "Parallel dark world" at ICRANet center in Pescara. In this context, he discussed the possibility that dark matter is a sort of "baryonic" matter from parallel/mirror hidden sector of particles which can be exactly identical to that of ordinary particles, or represent its somewhat deformed version. Possible interaction processes between ordinary and dark particles are of particular interest since they can be at the origin of baryogenesis and dark baryogenesis and naturally explain why ordinary and dark matter fractions in the Universe are comparable. On the other hand, these interactions can be tested at laboratories via specific low-cost experiments.
Please, see the link: http://www.icranet.org/index.php?option=com_content&task=blogcategory&id=89&Itemid=781

7. Technical-scientific report of the project "Del Talento e della curiosità. Quando l'aquila e il passero volano insieme" (ICRA,ICRANET, Fondazione Marco Besso, ECIPA)

Among the objects that have successfully followed the development of human being, the most significant and important has been the "Crab Nebula", chosen as symbol of the project. Discovered in 1054 as a “guest star”, it is now called “Crab Nebula” for its morphological appearance, similar to a crab, which has inside a Pulsar NPO532, which rotates with a period of 33 milliseconds and which in 1968 was identified as a rotating neutron star.

Please, look at Figure 12 where are:
I. The Chinese writing concerning the discovery of the "guest star", registered in July 1054 from Chinese, Korean and Japanese astronomers;
II. The splendid image of the Crab Nebula made by the Hubble Space Telescope in 2014 with its filamentary structures, still expanding today with velocity about 250 km / sec;
III. The X-ray emission from the Crab pulsar and its wind nebula observed by the satellite CHANDRA.

This has been the thread of the exhibitions organized by ICRA and ICRANet, whose major analysis carried on in the last 50 years have been devoted to the comprehension of Neutron Stars, at the discovery of the first Black Hole (see Figure 13) and, recently, to the physics of Gamma Ray Bursts. Those have allowed to join and light up the most distant and darkest parts of the Universe, going back to its early stages and to the Big Bang. The energy emitted by a GRB is equivalent to the one emitted by a billion of galaxies, each consisting of 100 billions of stars, even if only for a time duration of about hundreds of seconds.
Figure 12 – The Chinese writing concerning the discovery of the "guest star" (1054), the of the Crab Nebula made by the Hubble Space Telescope and the X-ray emission from the Crab pulsar and its wind nebula. Figure 13 – Professor Remo Ruffini receives the Cressy-Morrison Award (1972) form the New York Academy of Science, for the discovery of the first black hole in the galaxy.

The comprehension of those phenomena has a long and progressive history, in which relevant events have became possible thanks to the cooperation among East and West and to fundamental conceptual revolutions introduced by three "giants": Albert Einstein, Werner Heisenberg and Enrico Fermi. All those have been possible also thanks to the special relationship between Italy and China, to the crucial role played by Italy in the Albert Einstein’s formulation of general and special relativity, to the collaboration among Michele Besso and Marcel Grossmann with the major Italian mathematicians (as Ricci Curbastro and Tullio Levi Civita), and thanks also to the revolutionary role of Fermi in Cosmology, still unknown to the public.
To check the material of the 2 exhibitions "ICRANet and China" and "Einstein, Fermi and Heisenberg: the birth of Relativistic Astrophysics", see: http://www.fondazionemarcobesso.it/3362/inaugurazione-mostre-einstein-fermi-e-heisenberg-e-la-nascita-della-astrofisica-relativistica-e-icranet-e-cina-2/

To read the biography "Marcel Grosmann. For the love of Mathematics", please see: https://www.amazon.it/Marcel-Grossmann-Mathematics-Springer-Biographies-ebook/dp/B07DMD4VNH/ref=sr_1_1?ie=UTF8&qid=1532701370&sr=8-1&keywords=Marcel+Grossmann+For+the+Love+of+Mathematics (English)
https://www.amazon.it/Marcel-Grossmann-Aus-Liebe-Mathematik/dp/3905894327/ref=sr_1_fkmr0_1?ie=UTF8&qid=1532701370&sr=8-1-fkmr0&keywords=Marcel+Grossmann+For+the+Love+of+Mathematics (German)

In the framework of this project, the books "Fermi e l'Astrofisica" (being printed in Singapore) and "Einstein, Heisenberg and Fermi and the birth of Relativistic Astrophysics", have been completed.
Several chapters of those books have been presented during the conferences held in the framework of the project from Professor Roy Patrick Kerr, Crafoord Prize for Astronomy 2016, awarded by the King of Sweden (see Figure 14).

Figure 14 – Prof. Roy Patrick Kerr, Crafoord Prize for Astronomy 2016, during his conference “Cracking the Einstein code”, held at Fondazione Besso in Rome.

In those conferences, held at Fondazione Besso and Sapienza University in Rome, several eminent astrophysics (see Figures 15, 16, 17, 18) as Marco Tavani (https://youtu.be/E7t0TkuK6Bc), Massimo Della Valle (https://youtu.be/9rjA-5ZgkOE), Fulvio Ricci (https://youtu.be/BXUH2hxlZGU), Roy Kerr (https://youtu.be/9rjA-5ZgkOE), Paolo de Bernardis (https://youtu.be/dJGBH6cuaXA) and Paolo Giommi, as well as several ICRANet PhD students (see Figures 19, 20, 21, 22, 23), have presented their high levels scientific reports, filmed and broadcasted in order so that can be used for important researches in the following years.
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Figure 15 – Professor Marco Tavani during his conference "Radiazioni di GeV osservate da AGILE". Figure 16 – Professor Massimo Della Valle during his conference "L’arcobaleno e le stelle d’oro".
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Figure 17 – Professor Fulvio Ricci during his Lectio Magistralis "Gravitational Waves observations". Figure 18 – Professor Paolo De Bernardis during his Lectio Magistralis "La luce più antica dell'universo".

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Figures 19, 20, 21, 22 – From left to right: ICRANet PhD students Daria Promorac, Rahim Moradi, Wang Yu e Yerlan Aimuratov, during their presentations at Fondazione Besso.

8. Congratulations to ICRANet Faculty Professor Gregory Vereshaghin, awarded of the Doctor of Sciences (DSc) degree in theoretical physics, 13 June 2018

On the 13 June 2018, ICRANet Faculty Professor Gregory Vereshchagin has been awarded the Doctor of Sciences (D Sc) degree in theoretical physics, as announced by the Higher Attestation Commission (VAK) of Belarus (http://www.vak.org.by/node/4418). His dissertation “Kinetics, hydrodynamics and radiation of relativistic plasma" has been successfully defended on the 27 December 2017 (http://vak.org.by/node/3942). Professor Vereshchagin has become one of the few young Belarusian researchers, awarded of this highest scientific degree in his country under the age of 40.
Fig. 23 - Professor Gregory Vereshchagin during his dissertation on the 27 December 2017.

9. Seminars at ICRANet center in Pescara

* Seminars by Professor Shadi Tahvildar-Zadeh
29 From 17 to 30 June 2018, Professor Shadi Tahvildar-Zadeh (Rutgers, The State University of New Jersey – USA), visited ICRANet center in Pescara and gave a series of seminars to faculty members and students. The main topics discussed in his talks were: Theories of matter: Weyl, Einstein and Mie, the classification of singularities, the Bianchi identities and equations of motion, the Born-In field non linear electrodynamics, the Bopp-Landé-Thomas-Podolsky linear electrodynamics, the zero-gravity space times and Ring-like particles, the general relativistic hydrogen, the ground state of positronium and dark matter, the photons as particles and the electron-photon systems.

* Seminar by Sergio Andrés Vallejo Peña, 24 July 2018

On the 24 July 2018, Sergio Andrés Vallejo Peña, a visiting student from the Universidad de Antioquia (UDEA) – Colombia, gave two seminars on "The effects of anisotropy and non-adiabaticity on the evolution of the curvature perturbation" (https://arxiv.org/abs/1804.05005) and "The MESS of cosmological perturbations" (https://arxiv.org/abs/1806.01941).

* Seminar by Mikalai Prakapenia, 24 July 2018

On the 24 July 2018, Mikalai Prakapenia (Researcher at ICRANet-Minsk center and PhD student at Belarusian State University), gave an important seminar titled “Thermalization of electron-positron plasma with quantum degeneracy”. He reported on the analysis of the non-equilibrium electron-positron-photon plasma thermalization process studied using relativistic Boltzmann solver, taking into account quantum corrections both in non-relativistic and relativistic cases. Collision integrals are computed from exact QED matrix elements for all binary and triple interactions in the plasma. It is shown that in non-relativistic case binary interaction rates dominate over triple ones, resulting in establishment of kinetic equilibrium prior to final relaxation towards thermal equilibrium, in agreement with previous studies. On the contrary, in relativistic case triple interaction rates are fast enough to prevent establishment of kinetic equilibrium. It is shown that thermalization process strongly depends on quantum degeneracy in initial state, but does not depend on plasma composition.

10. Scientific visits to ICRANet

* Dr. Sonila Boçi visit to ICRANet, 30 April – 13 May 2018
From 30 April to 13 May 2018, Professor Sonila Boçi from University of Tirana – Albania, visited ICRANet center in Pescara. During her visit, she had the opportunity to discuss her scientific research and to have fruitful exchange of ideas with other researchers from ICRANet and from different parts of the world.

During the summer, several others relevant scientist and students visited our ICRANet center in Pescara, namely:
* Professor Clovis Achy Soares Maia (University of Brasilia – Brazil), 7 - 14 July 2018
* Phd students Sílvia Pereira Nunes, Ronaldo Vieira Lobato and Marcelo Montenegro Lapola (Instituto Tecnológico de Aeronáutica de São José dos Campos, SP – Brazil), 7 – 12 July 2018
* Professor Shadi Tahvildar-Zadeh (Rutgers, The State University of New Jersey – USA), 17 – 30 June 2018
* Soroush Shakeri (Isfahan University of Technology - Iran),19 June – 17 July 2018
* Prof. Mathews Grant (Center for Astrophysics at Notre Dame University – USA), 7 – 9 July 2018
* Professor Wenbin Lin (School of Physical Science and Technology, Southwest Jiaotong University – China), 8 – 14 July 2018
* Professor Hyung Won Lee (Inje University – South Korea), 16 July – 15 August 2018
* Sergio Andrés Vallejo Peña (Universidad de Antioquia – Colombia), 1 July – 9 September 2018
* Mikalai Prakapenia (ICRANet-Minsk center and Belarusian State University – Belarus), 1 – 27 July 2018

Prof. Sonila Boci
Prof. Clovis Achy Soares Maia
Prof. Shadi Tahvildar-Zadeh
Soroush Shakeri
Prof. Mathews Grant
Professor Hyung Won Lee
Mikalai Prakapenia

Prior and/or during their visit, those scientists had the opportunity to participate to the 15th Marcel Grossmann meeting in Rome, and to carry on important analysis and research with other ICRANet scientists from all over the world.

Following the Agreement between ICRANet and Al-Farabi Kazakh National University, two groups of Kazakh students, under the supervision of Professor Medeu Abishev, visited ICRANet center in Pescara. The first group came from 11 to 25 June 2018, and was composed by: Fariza Aitzhan, Makpal Akhmetzhanova, Albina Bazarova, Aizhan Duysenbaeva, Mamak Tangsholpan, Ernat Nurtazin, Balzhan Mamadkarimova and Tileuberdi Akhat.
A second group came from 30 June to 11 July, and was composed by: Sadirkhanov Zhandos, Abdramanova Gulbanu, Assel Kuanysh, Anel Imangaliyeva, Symbat Nurakhmetova, Anapiya Meruyert, Zaltay Aklen, Gaukhar Askhanova, Niyazov Kaiyrzhan, Yesbol Meirambekuly, Botakoz Seifullina and Fatima Dankenova.

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Fig. 24 - Kazakh students during their visit at ICRANet center in Pescara.

11. Recent publications

S. Gasparyan, N. Sahakyan, V. Baghmanyan, D. Zargaryan, "On the multi-wavelength Emission from CTA 102", accepted for publication on The Astrophysical Journal, on 8 July 2018.
We report on broadband observations of CTA 102 (z=1.037) during the active states in 2016-2017. In the γ-ray band, Fermi LAT observed several prominent flares which followed a harder-when-brighter behavior: the hardest photon index Γ=1.61±0.10 being unusual for FSRQs. The peak γ-ray flux above 100 MeV (3.55±0.55)×10−5 photon cm−2s−1 observed on MJD 57738.47 within 4.31 minutes, corresponds to an isotropic γ-ray luminosity of Lγ=3.25×1050ergs−1, comparable with the highest values observed from blazars so far. The analyses of the Swift UVOT/XRT data show an increase in the UV/optical and X-ray bands which is contemporaneous with the bright γ-ray periods. The X-ray spectrum observed by Swift XRT and NuSTAR during the γ-ray flaring period is characterized by a hard photon index of ∼1.30. The shortest e-folding time was 4.08±1.44 hours, suggesting a very compact emission region R≤δ×2.16×1014 cm. We modeled the spectral energy distribution of CTA 102 in several periods (having different properties in UV/optical, X-ray and γ-ray bands) assuming a compact blob inside and outside the BLR. We found that the high-energy data are better described when the infrared thermal radiation of the dusty torus is considered. In the flaring periods when the correlation between the γ-ray and UV/optical/X-ray bands is lacking, the γ-ray emission can be produced from the interaction of fresh electrons in a different blob, which does not make a dominant contribution at lower energies.
Link: https://arxiv.org/abs/1807.02869v1

P. Padovani, P. Giommi, E. Resconi, T. Glauch, B. Arsioli, N. Sahakyan, M. Huber,“Dissecting the region around IceCube-170922A: the blazar TXS 0506+056 as the first cosmic neutrino source”, accepted for publication in MNRAS on 12 July 2018.
We present the dissection in space, time, and energy of the region around the IceCube-170922A neutrino alert. This study is motivated by: (1) the first association between a neutrino alert and a blazar in a flaring state, TXS 0506+056; (2) the evidence of a neutrino flaring activity during 2014 - 2015 from the same direction; (3) the lack of an accompanying simultaneous γ-ray enhancement from the same counterpart; (4) the contrasting flaring activity of a neighbouring bright γ-ray source, the blazar PKS 0502+049, during 2014 - 2015. Our study makes use of multi-wavelength archival data accessed through Open Universe tools and includes a new analysis of Fermi-LAT data. We find that PKS 0502+049 contaminates the γ-ray emission region at low energies but TXS 0506+056 dominates the sky above a few GeV. TXS 0506+056, which is a very strong (top percent) radio and γ-ray source, is in a high γ-ray state during the neutrino alert but in a low though hard γ-ray state in coincidence with the neutrino flare. Both states can be reconciled with the energy associated with the neutrino emission and, in particular during the low/hard state, there is evidence that TXS 0506+056 has undergone a hadronic flare with very important implications for blazar modelling. All multi-messenger diagnostics reported here support a single coherent picture in which TXS 0506+056, a very high energy γ-ray blazar, is the only counterpart of all the neutrino emissions in the region and therefore the most plausible first non-stellar neutrino and, hence, cosmic ray source.
Link: https://arxiv.org/abs/1807.04461

T. Hayashinaka, S. Xue, “Physical renormalization condition for de Sitter QED”, Published in Rapid communication section of Phys. Rev. D 97, 105010, on 13 February 2018.
We considered a new renormalization condition for the vacuum expectation values of the scalar and spinor currents induced by a homogeneous and constant electric field background in de Sitter spacetime. Following a semiclassical argument, the condition named maximal subtraction imposes the exponential suppression on the massive charged particle limit of the renormalized currents. The maximal subtraction changes the behaviors of the induced currents previously obtained by the conventional minimal subtraction scheme. The maximal subtraction is favored for a couple of physically decent predictions including the identical asymptotic behavior of the scalar and spinor currents, the removal of the infrared (IR) hyperconductivity from the scalar current, and the finite current for the massless fermion.
Link: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.105010

C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini, “Novel constraints on fermionic dark matter from galactic observables I: The Milky Way”, accepted for publication on Physics of the Dark Universe, Volume 21, on 12 July 2018.
We have recently introduced a new model for the distribution of dark matter (DM) in galaxies based on a self-gravitating system of massive fermions at finite temperatures, the Ruffini–Argüelles–Rueda (RAR) model. We show that this model, for fermion masses in the keV range, explains the DM halo of the Galaxy and predicts the existence of a denser quantum core at the center. We demonstrate here that the introduction of a cutoff in the fermion phase-space distribution, necessary to account for the finite Galaxy size, defines a new solution with a central core which represents an alternative to the black hole (BH) scenario for SgrA*. For a fermion mass in the range mc2=48-345 keV, the DM halo distribution is in agreement with the Milky Way rotation curve data, while harbors a dense quantum core of about 4x106 solar masses within the S2-star pericenter.
Link: https://www.sciencedirect.com/science/article/pii/S2212686418300815

M.A. Prakapenia, I.A.Siutsou, G.V. Vereshchagin, “Numerical scheme for treatment of Uehling–Uhlenbeck equation for two-particle interactions in relativistic plasma, accepted for publication on the Journal of Computational Physics, on 4 July 2018.
We present a new efficient method to compute Uehling–Uhlenbeck collision integral for all two-particle interactions in relativistic plasma with drastic improvement in computation time with respect to existing methods. Plasma is assumed isotropic in momentum space. The set of reactions consists of: Moeller and Bhabha scattering, Compton scattering, two-photon pair annihilation, and two-photon pair production, which are described by QED matrix elements. In our method exact energy and particle number conservation laws are fulfilled. Reaction rates are compared, where possible, with the corresponding analytical expressions and convergence of numerical rates is demonstrated.
Link: https://www.sciencedirect.com/science/article/pii/S0021999118304650?via%3Dihub

B. Arsioli, U. Barres de Almeida, E. Prandini, B. Fraga, L. Foffano, “Extreme & High Synchrotron Peaked Blazars at the limit of Fermi-LAT detectability: the γ-ray spectrum of 1BIGB sources”, published on Monthly Notices of the Royal Astronomical Society, sty1975, on 24 July 2018.
We present the 1-100 GeV spectral energy distribution for a population of 148 high-synchrotron-peaked blazars (HSPs) recently detected with Fermi-LAT as part of the First Brazil-ICRANet Gamma-ray Blazar catalogue (1BIGB). Most of the 1BIGB sources have their γ-ray spectral properties presented here for the first time, representing a significant new extension of the γ-ray blazar population. Since our sample was originally selected from an excess signal in the 0.3 - 500 GeV band, the sources stand out as promising TeV blazar candidates, potentially in reach of the forthcoming very-high-energy (VHE) γ-ray observatory, CTA. The flux estimates presented here are derived considering PASS8 data, integrating over more than 9 years of Fermi-LAT observations. We also review the full broadband fit between 0.3-500 GeV presented in the original 1BIGB paper for all sources, updating the power-law parameters with currently available Fermi-LAT dataset. The importance of these sources in the context of VHE population studies with both current instruments and the future CTA is evaluated. To do so, we select a subsample of 1BIGB sources and extrapolate their γ-ray SEDs to the highest energies, properly accounting for absorption due to the extragalactic background light. We compare those extrapolations to the published CTA sensitivity curves and estimate their detectability by CTA. Two notable sources from our sample, namely 1BIGB J224910.6-130002 and 1BIGB J194356.2+211821, are discussed in greater detail. All γ-ray SEDs, are made publicly available via the Brazilian Science Data Center (BSDC) service, maintained at CBPF, in Rio de Janeiro.
Link: https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/sty1975/5057880

R. Ruffini, J. Rodriguez, M. Muccino, J. A. Rueda, Y. Aimuratov, U. Barres de Almeida, L. Becerra, C. L. Bianco, C. Cherubini, S. Filippi, D. Gizzi, M. Kovacevic, R. Moradi, F. G. Oliveira, G. B. Pisani, and Y. Wang, “On the Rate and on the Gravitational Wave Emission of Short and Long GRBs” published on The Astrophysical Journal, Volume 859, Number 1 on 18 May 2018.
On the ground of the large number of gamma-ray bursts (GRBs) detected with cosmological redshift, we classified GRBs in seven subclasses, all with binary progenitors which emit gravitational waves (GWs). Each binary is composed of combinations of carbon–oxygen cores (COcore), neutron stars (NSs), black holes (BHs), and white dwarfs (WDs). The long bursts, traditionally assumed to originate from a BH with an ultrarelativistic jetted emission, not emitting GWs, have been subclassified as (I) X-ray flashes (XRFs), (II) binary-driven hypernovae (BdHNe), and (III) BH–supernovae (BH–SNe). They are framed within the induced gravitational collapse paradigm with a progenitor COcore–NS/BH binary. The SN explosion of the COcore triggers an accretion process onto the NS/BH. If the accretion does not lead the NS to its critical mass, an XRF occurs, while when the BH is present or formed by accretion, a BdHN occurs. When the binaries are not disrupted, XRFs lead to NS–NS and BdHNe lead to NS–BH. The short bursts, originating in NS–NS, are subclassified as (IV) short gamma-ray flashes (S-GRFs) and (V) short GRBs (S-GRBs), the latter when a BH is formed. There are (VI) ultrashort GRBs (U-GRBs) and (VII) gamma-ray flashes (GRFs) formed in NS–BH and NS–WD, respectively. We use the occurrence rate and GW emission of these subclasses to assess their detectability by Advanced LIGO-Virgo, eLISA, and resonant bars. We discuss the consequences of our results in view of the announcement of the LIGO/Virgo Collaboration of the source GW 170817 as being originated by an NS–NS.
Link: http://iopscience.iop.org/article/10.3847/1538-4357/aabee4/meta

D. Bini, T. Damour, A. Geralico, “Spin-orbit precession along eccentric orbits: Improving the knowledge of self-force corrections and of their effective-one-body counterparts”, published on Phys. Rev. D 97, 104046 (2018) on 25 May 2018.
The (first-order) gravitational self-force correction to the spin-orbit precession of a spinning compact body along a slightly eccentric orbit around a Schwarzschild black hole is computed through the ninth post-Newtonian order, improving recent results by Kavanagh et al. [Phys. Rev. D 96, 064012 (2017).] This information is then converted into its corresponding Effective-One-Body counterpart, thereby determining several new post-Newtonian terms in the gyrogravitomagnetic ratio gS∗.

D. Bini, T. Damour, A. Geralico, C. Kavanagh, “Detweiler’s redshift invariant for spinning particles along circular orbits on a Schwarzschild background”, published on Phys. Rev. D 97, 104022 (2018) on 18 May 2018.
We study the metric perturbations induced by a classical spinning particle moving along a circular orbit on a Schwarzschild background, limiting the analysis to effects which are first order in spin. The particle is assumed to move on the equatorial plane and has its spin aligned with the z-axis. The metric perturbations are obtained by using two different approaches, i.e., by working in two different gauges: the Regge-Wheeler gauge (using the Regge-Wheeler-Zerilli formalism) and a radiation gauge (using the Teukolsky formalism). We then compute the linear-in-spin contribution to the first-order self-force contribution to Detweiler's redshift invariant up to the 8.5 post-Newtonian order. We check that our result is the same in both gauges, as appropriate for a gauge-invariant quantity, and agrees with the currently known 3.5 post-Newtonian results.
Link: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.104022

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