This work aims to show if it is possible to perform distance measurements, complementing type Ia supernovae with the fusion of black holes. It will be evaluated if it is possible to refine the measurement of the accelerated expansion of the universe, through the detection of gravitational waves generated by the fusion of black holes and comparing them with the intrinsic luminosity of type Ia supernovae.
{"title":"Type Ia supernovas and fusion of black holes: Do they complement each other in measuring the expansion of the universe?","authors":"R. Schneider","doi":"10.22323/1.329.0024","DOIUrl":"https://doi.org/10.22323/1.329.0024","url":null,"abstract":"This work aims to show if it is possible to perform distance measurements, complementing type Ia supernovae with the fusion of black holes. It will be evaluated if it is possible to refine the measurement of the accelerated expansion of the universe, through the detection of gravitational waves generated by the fusion of black holes and comparing them with the intrinsic luminosity of type Ia supernovae.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115810240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MAGIC is a system of two 17m Cherenkov telescopes for very high energy gamma-ray and cosmic-ray astrophysics and currently one of the best performing in the field. Through the discovery of more than 50 extragalactic and galactic sources including blazars, radiogalaxies, pulsars, supernovae remnants and binary systems (among other types) a broad range of topics can be studied: accretion to black holes, relativistic jets, shocks and their connection to the acceleration of cosmic rays. In addition, MAGIC tries to answer fundamental physics questions, such as the search for dark matter. In this talk I will discuss some selected highlights from MAGIC, especially the recent detection of very high energy gamma-rays from the blazar TXS 0506+056, which could potentially be the source of the high-energy extragalactic neutrino recently detected by Icecube.
{"title":"MAGIC and the very high energy gamma-ray sky","authors":"B. Fraga","doi":"10.22323/1.329.0004","DOIUrl":"https://doi.org/10.22323/1.329.0004","url":null,"abstract":"MAGIC is a system of two 17m Cherenkov telescopes for very high energy gamma-ray and cosmic-ray astrophysics and currently one of the best performing in the field. Through the discovery of more than 50 extragalactic and galactic sources including blazars, radiogalaxies, pulsars, supernovae remnants and binary systems (among other types) a broad range of topics can be studied: accretion to black holes, relativistic jets, shocks and their connection to the acceleration of cosmic rays. In addition, MAGIC tries to answer fundamental physics questions, such as the search for dark matter. In this talk I will discuss some selected highlights from MAGIC, especially the recent detection of very high energy gamma-rays from the blazar TXS 0506+056, which could potentially be the source of the high-energy extragalactic neutrino recently detected by Icecube.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130169312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present work we review the circumstances under which charged particles can escape black hole gravitational fields after its collision with another particle. Here we examine the dynamics of neutral and charged particles interacting with slowly and rapidly rotating Kerr black holes in the presence of magnetic fields. In this respect, rotating black holes may act as particle accelerators under certain circumstances. Axially symmetric magnetic field homogeneous at infinity and other type of configurations are discussed. It is analyzed the effective potential of the system, as well the center of mass energy and the escape velocity of the particles. As appointed by many examples in the literature, some of the main results point that the intensity of the magnetic fields induces the innermost stable circular orbit (ISCO) to be closer to the black hole horizon. There is a range of possible values for the spin a and for the magnetic field such that particles should escape from the system. The present investigation on particle escape velocity can possibly contribute, for example, to constrain AGN dynamic properties to properly understand the acceleration mechanisms of the highest energy cosmic rays in the universe.
{"title":"Rotating black holes with magnetic fields as accelerators of charged particles","authors":"C. H. C. Araujo, R. C. Anjos","doi":"10.22323/1.329.0005","DOIUrl":"https://doi.org/10.22323/1.329.0005","url":null,"abstract":"In the present work we review the circumstances under which charged particles can escape black hole gravitational fields after its collision with another particle. Here we examine the dynamics of neutral and charged particles interacting with slowly and rapidly rotating Kerr black holes in the presence of magnetic fields. In this respect, rotating black holes may act as particle accelerators under certain circumstances. Axially symmetric magnetic field homogeneous at infinity and other type of configurations are discussed. It is analyzed the effective potential of the system, as well the center of mass energy and the escape velocity of the particles. As appointed by many examples in the literature, some of the main results point that the intensity of the magnetic fields induces the innermost stable circular orbit (ISCO) to be closer to the black hole horizon. There is a range of possible values for the spin a and for the magnetic field such that particles should escape from the system. The present investigation on particle escape velocity can possibly contribute, for example, to constrain AGN dynamic properties to properly understand the acceleration mechanisms of the highest energy cosmic rays in the universe.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124035955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. M. Amarilo, Mapse Barroso F. Filho, R. V. Maluf
In this work, we search how the production of gravitational waves is corrected by a spontaneous Lorentz violation triggered by the vacuum expectation value (VEV) of the bumblebee vector field (bμ ). We consider the modified graviton equations of motion by the dynamics of the bumblebee field. In this formulation the graviton is still non-massive and has two degrees of freedom, but does not has a gauge transformation and the dispersion relation changes from p2 = 0 to p2 + ξ (bμ pμ) = 0. Then, we solve these equations considering a current that acts as a source of the radiation. In this case, we apply the method of the Green’s function to find a modified quadrupole formula for the perturbation.
{"title":"Modification in Gravitational Waves Production Triggered by Spontaneous Lorentz Violation","authors":"K. M. Amarilo, Mapse Barroso F. Filho, R. V. Maluf","doi":"10.22323/1.329.0015","DOIUrl":"https://doi.org/10.22323/1.329.0015","url":null,"abstract":"In this work, we search how the production of gravitational waves is corrected by a spontaneous Lorentz violation triggered by the vacuum expectation value (VEV) of the bumblebee vector field (bμ ). We consider the modified graviton equations of motion by the dynamics of the bumblebee field. In this formulation the graviton is still non-massive and has two degrees of freedom, but does not has a gauge transformation and the dispersion relation changes from p2 = 0 to p2 + ξ (bμ pμ) = 0. Then, we solve these equations considering a current that acts as a source of the radiation. In this case, we apply the method of the Green’s function to find a modified quadrupole formula for the perturbation.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128142669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luiz Gustavo Egito da Silva, Antônio de Pádua Santos, E. Pereira
Black holes have always been of great interest in gravitation and high energy particles. Through their interaction with light and matter, it is possible to understand their behavior. However, there is an apparent difficulty in studying it in the laboratory, in addition to the complex equations representing them, in particular when we left for black holes without singularities. In this work, we use a finite element software to simulate the metric of black holes without singularities in condensed matter systems. For these non-singular black holes, the idea is to use the metric tensor as a unitary element $ds^2$ and make this metric as the electric permittivity of material to be simulated in software. We study a plane wave on the influence of the black hole, presenting how the light is disturbed by the presence of the black hole. Then it is possible to identify a light signature of the presence of black holes, thus helping their detection and study of their properties.
{"title":"Black Hole Simulations in Condensed Matter Systems","authors":"Luiz Gustavo Egito da Silva, Antônio de Pádua Santos, E. Pereira","doi":"10.22323/1.329.0029","DOIUrl":"https://doi.org/10.22323/1.329.0029","url":null,"abstract":"Black holes have always been of great interest in gravitation and high energy particles. Through their interaction with light and matter, it is possible to understand their behavior. However, there is an apparent difficulty in studying it in the laboratory, in addition to the complex equations representing them, in particular when we left for black holes without singularities. In this work, we use a finite element software to simulate the metric of black holes without singularities in condensed matter systems. For these non-singular black holes, the idea is to use the metric tensor as a unitary element $ds^2$ and make this metric as the electric permittivity of material to be simulated in software. We study a plane wave on the influence of the black hole, presenting how the light is disturbed by the presence of the black hole. Then it is possible to identify a light signature of the presence of black holes, thus helping their detection and study of their properties.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133221719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. C. Lucizani, L. Cabral, P. Seidel, A. Capistrano
We consider a massive spinless particle in a particular curved space-time described by a phase space formalism. For this space-time, we determine nontrivial conserved quantities and geometrical invariants by analytical and numerical methods. By analytic calculations, we revisit (perform) a method to relate two kinds of geometries associated with conserved quantities, whose dual metrics are constructed. The method relies on the calculation of the Stackel-Killing tensors (SKT) presented in a spherically symmetric space-time. We have a system of partial differential equations (PDE) for the symmetric components of the SKT obtained for a given space-time metric. We note that the PDE system is highly non-trivial according to the isometry structure of the original metric. A degenerate metric solution appears in the dual structure, and it is compared with recent works involving space-time bridge solutions in vacuum gravity and nontrivial extensions of the Schwarzschild space-time.
{"title":"Degenerate metrics on a dual geometry of spherically symmetric space-time","authors":"A. C. Lucizani, L. Cabral, P. Seidel, A. Capistrano","doi":"10.22323/1.329.0003","DOIUrl":"https://doi.org/10.22323/1.329.0003","url":null,"abstract":"We consider a massive spinless particle in a particular curved space-time described by a phase space formalism. For this space-time, we determine nontrivial conserved quantities and geometrical invariants by analytical and numerical methods. By analytic calculations, we revisit (perform) a method to relate two kinds of geometries associated with conserved quantities, whose dual metrics are constructed. The method relies on the calculation of the Stackel-Killing tensors (SKT) presented in a spherically symmetric space-time. We have a system of partial differential equations (PDE) for the symmetric components of the SKT obtained for a given space-time metric. We note that the PDE system is highly non-trivial according to the isometry structure of the original metric. A degenerate metric solution appears in the dual structure, and it is compared with recent works involving space-time bridge solutions in vacuum gravity and nontrivial extensions of the Schwarzschild space-time.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114266534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The origin and nature of the ultrahigh energy cosmic rays (UHECRs) are still unknown. However, great progress has been achieved in past years due to the observations performed by the Pierre Auger Observatory and Telescope Array. Above $10^{18}$ eV the observed energy spectrum presents two features: a hardening of the slope at about $10^{18.7}$ eV, which is known as the ankle and a suppression at approximately $10^{19.6}$ eV. The composition inferred from the experimental data, interpreted by using the current high energy hadronic interaction models, seems to be light below the ankle, showing a trend to heavier nuclei for increasing values of the primary energy. Current high energy hadronic interaction models, updated by using Large Hadron Collider data, are still subject to large systematic uncertainties, which makes difficult the interpretation of the experimental data in terms of composition. On the other hand, it is very well known that gamma rays and neutrinos are produced by UHECRs during propagation from their sources, as a consequence of their interactions with the radiation field present in the universe. The flux at Earth of these secondary particles depends on the source models of UHECRs including the chemical composition at injection. Therefore, both gamma-ray and neutrino observations can be used to constrain source models of UHECRs, including the composition in a way which is independent of the high energy hadronic interaction models. In this article I will review recent results obtained by using the latest gamma-ray and neutrino observations.
{"title":"Implications of gamma-ray and neutrino observations on source models of ultrahigh energy cosmic rays","authors":"A. Supanitsky","doi":"10.22323/1.329.0006","DOIUrl":"https://doi.org/10.22323/1.329.0006","url":null,"abstract":"The origin and nature of the ultrahigh energy cosmic rays (UHECRs) are still unknown. However, great progress has been achieved in past years due to the observations performed by the Pierre Auger Observatory and Telescope Array. Above $10^{18}$ eV the observed energy spectrum presents two features: a hardening of the slope at about $10^{18.7}$ eV, which is known as the ankle and a suppression at approximately $10^{19.6}$ eV. The composition inferred from the experimental data, interpreted by using the current high energy hadronic interaction models, seems to be light below the ankle, showing a trend to heavier nuclei for increasing values of the primary energy. Current high energy hadronic interaction models, updated by using Large Hadron Collider data, are still subject to large systematic uncertainties, which makes difficult the interpretation of the experimental data in terms of composition. On the other hand, it is very well known that gamma rays and neutrinos are produced by UHECRs during propagation from their sources, as a consequence of their interactions with the radiation field present in the universe. The flux at Earth of these secondary particles depends on the source models of UHECRs including the chemical composition at injection. Therefore, both gamma-ray and neutrino observations can be used to constrain source models of UHECRs, including the composition in a way which is independent of the high energy hadronic interaction models. In this article I will review recent results obtained by using the latest gamma-ray and neutrino observations.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121955502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. F. Barroso, K. M. Amarilo, Roberto Vinhaes Maluf Cavalcante
{"title":"Effects of Lorentz Symmetry Violation in the Gravitational Waves Polarization","authors":"M. F. Barroso, K. M. Amarilo, Roberto Vinhaes Maluf Cavalcante","doi":"10.22323/1.329.0018","DOIUrl":"https://doi.org/10.22323/1.329.0018","url":null,"abstract":"","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115605447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fast magnetic reconnection events can play an important role in accretion disk systems. A potential model to explain the non-thermal very-high-energy (VHE) emission (from GeV to TeV) observed in black-hole binaries (BHBs) and Active Galatic Nuclei (AGNs) can be attributed to fast magnetic reconnection induced in the turbulent corona of accretion disks and/or jets. In this work, we will discuss the results of global general relativistic MHD (GRMHD) simulations of accretion disks around black holes, whose turbulence is naturally driven by MHD instabilities, such as the magnetorotational instability (MRI). We will also present studies of magnetic reconnection driven by kink instabilities inside jets employing special relativistic MHD (SRMHD) simulations. As we expect, our simulations reveal the development of a nearly steady-state turbulence driven by these instabilities. We have performed a detailed statistical analysis to identify the presence of current sheets in the turbulent regions of both the accretion flow and jet. We then determined the magnetic reconnection rates in these locations obtaining average reconnection velocities in Alfven speed units of the order of $0.01-0.7$, which are consistent with the predictions of the theory of turbulence-induced fast reconnection.
{"title":"A statistical study of fast magnetic reconnection in turbulent accretion disks and jets","authors":"L. Kadowaki, E. Pino, Tania E. Medina-Torrej'on","doi":"10.22323/1.329.0016","DOIUrl":"https://doi.org/10.22323/1.329.0016","url":null,"abstract":"Fast magnetic reconnection events can play an important role in accretion disk systems. A potential model to explain the non-thermal very-high-energy (VHE) emission (from GeV to TeV) observed in black-hole binaries (BHBs) and Active Galatic Nuclei (AGNs) can be attributed to fast magnetic reconnection induced in the turbulent corona of accretion disks and/or jets. In this work, we will discuss the results of global general relativistic MHD (GRMHD) simulations of accretion disks around black holes, whose turbulence is naturally driven by MHD instabilities, such as the magnetorotational instability (MRI). We will also present studies of magnetic reconnection driven by kink instabilities inside jets employing special relativistic MHD (SRMHD) simulations. As we expect, our simulations reveal the development of a nearly steady-state turbulence driven by these instabilities. We have performed a detailed statistical analysis to identify the presence of current sheets in the turbulent regions of both the accretion flow and jet. We then determined the magnetic reconnection rates in these locations obtaining average reconnection velocities in Alfven speed units of the order of $0.01-0.7$, which are consistent with the predictions of the theory of turbulence-induced fast reconnection.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116051138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Pino, R. A. Batista, G. Kowal, Tania E. Medina-Torrej'on, Juan Carlos Ramírez-Rodríguez
Particle acceleration by magnetic reconnection is now recognized as an important process in magnetically dominated regions of galactic and extragalactic black hole sources. This process helps to solve current puzzles specially related to the origin of the very high energy flare emission in these sources. In this review, we discuss this acceleration mechanism and show recent analytical studies and multidimensional numerical SRMHD and GRMHD (special and general relativistic magnetohydrodynamical) simulations with the injection of test particles, which help us to understand this process both in relativistic jets and coronal regions of these sources. The very high energy and neutrino emission resulting from the accelerated particles by reconnection is also discussed.
{"title":"Magnetic reconnection, Cosmic Ray Acceleration and Gamma-Ray emission around Black Holes and Relativistic Jets","authors":"E. Pino, R. A. Batista, G. Kowal, Tania E. Medina-Torrej'on, Juan Carlos Ramírez-Rodríguez","doi":"10.22323/1.329.0008","DOIUrl":"https://doi.org/10.22323/1.329.0008","url":null,"abstract":"Particle acceleration by magnetic reconnection is now recognized as an important process in magnetically dominated regions of galactic and extragalactic black hole sources. This process helps to solve current puzzles specially related to the origin of the very high energy flare emission in these sources. In this review, we discuss this acceleration mechanism and show recent analytical studies and multidimensional numerical SRMHD and GRMHD (special and general relativistic magnetohydrodynamical) simulations with the injection of test particles, which help us to understand this process both in relativistic jets and coronal regions of these sources. The very high energy and neutrino emission resulting from the accelerated particles by reconnection is also discussed.","PeriodicalId":416656,"journal":{"name":"Proceedings of International Conference on Black Holes as Cosmic Batteries: UHECRs and Multimessenger Astronomy — PoS(BHCB2018)","volume":"107 5S 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134499519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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