StronGrHEP project deliverables
The page lists 15 deliverables related to the research project "StronGrHEP".
List of Deliverables
| title and desprition | type | last update |
|---|---|---|
Black holes with gauge fields\"Building on deliverable 5, analytic methods will be combined with numerical tools to study black-hole solutions with vector or \"\"gauge\"\" fields. Time evolutions of single-black-hole solutions obtained from the Einstein equations coupled to the Maxwell equations will be analysed and the results compared with approximation calculations. The stability of the spacetimes will be explored through studying different types of initial perturbations superposed onto the initial black-hole solution. The emission of gravitational and scalar radiation will be computed.\" Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Collisions of hairy BHs\"Black holes surrounded by long-term stable, fundamental fields act \"\"in some aspects\"\" like astrophysical black holes surrounded by accretion disks. As such, these systems can be used to understand possible modified gravitational-wave emission and other dynamical effects. We will perform collisions of black holes surrounded by scalar clouds. The initial data for this problem can be set using previous work by team members. The alignment of black hole spin with accretion disks is a robust prediction of basically all models, but it has yet to be verified though nonlinear evolutions. We will perform such evolutions in a carefully selected setup with bosonic clouds. We will further explore scenarios where matter is allowed to couple to bosonic fields. There, objects orbiting around supermassive black holes may \"\"float\"\" on a fixed circular geodesic for long timescales, energy being drawn from the hole\'s rotational energy. Floating orbits are observationally interesting, producing Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Black-hole grazing collisionsUsing the tools developed in the previous delivrables, we will perform simulations of grazing collisions of black holes in higher dimensions and extract the gravitational waves from these collisions, the scattering threshold, i.e. the impact parameter below which the collision leads to formation of a single black hole and above which the colliding objects scatter off to infinity. The possibility of super-Planckian curvature will be explored extending existing results in the literature. The results will be compared with shock-wave and particle calculations which furthermore serve as possible methods to extrapolate results to infinite boost parameters. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Bounds on particle masses using gravityBuilding on the previous deliverables, we will provide detailed models of the evolution of axion-like particles in strong-field gravity. This will involve nonlinear evolutions of the Einstein field equations with non-trivial sources, including realistic stars and magnetic fields. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Shadows of black-hole binariesUse numerical methods to evolve in time a binary of hairy black hole solutions to obtain gravitational wave templates of the process and monitor the scalar hair dynamics. A particularly interesting question is how the scalar field settles down in the final configuration. Initial evolutions will be performed for the hairy black hole solutions found by team members in previous work. and subsequently extended to more general models. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Wave extraction, initial dataGeneralize the wave extraction tools to the case of non-axisymmetric spacetime. Similarly generalize the construction of initial data, that is solutions to the Einstein constraint equations, to black holes with non-zero impact parameter. Perform test simulations of grazing collisions to ensure high accuracy of these tools. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Smoking GunsUse numerical and analytic methods to construct an explicit form of the spacetime metric describing black holes and neutron stars in a large class of modified gravity theories. This will be a fundamental tool to identify new unexpected phenomena occurring in such theories in the strong-field regime, which could be used as “smoking guns†for deviation from general relativity in this regime. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-04-02 |
Compact binary waveformGravitational waveforms emitted in compact binary mergers, computed in modified theories of gravity such as extended scalar-tensor gravity (Horndesky), quadratic gravity Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Black holes with scalar fieldsCombining analytic with numerical work, black-hole solutions with scalar fields will be studied. Time evolutions of single-black-hole solutions obtained from the Einstein equations coupled to the Klein-Gordon equations will be analysed and the results compared with approximation calculations. The stability of the spacetimes will be explored through studying different types of initial perturbations superposed onto the initial black-hole solution. The emission of gravitational and scalar radiation will be computed. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Structure of stars withdark coresThe capture of dark matter by neutron stars is expected to lead to gravitational collapse of the system with strong electromagnetic signatures. Notwithstanding, a detailed model for dark matter accretion or star composition has not been developed to date. We will model dark-matter stars through composite boson-fermion matter and compute the stability diagram and time-development of these configurations. In addition, we will model the interaction of dark matter with the star material, and consequent triggering of superradiance in stars. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Astrophysical ObservablesDetermine astrophysical observables, to be detected by X-ray (ATHENA, LOFT) and radio telescopes (PTA) carrying the imprint of possible modified gravity theories, such as quasi-periodic oscillations in the X-ray flux from accreting black holes and modifications in the binary pulsar orbits (month 24). Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Shadows of single black holesNumerically evolve boson-stars and single-black-hole spacetimes with hair for the case of self-interaction of the scalar field. Identify smoking guns of the self-interaction. Extend the study to higher-dimensional black holes of non-spherical topology and determine the stability of these spacetimes through fully non-linear evolutions by adding bar-shaped perturbations to the initial analytic solutions. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Non-linear superradiant instabilityOne outstanding issue left unresolved in the understanding of superradiant instabilities concerns accurate, long-term nonlinear evolutions of the development of superradiant instabilities around black holes. These are important to verify recent claims that the instability can be understood with linear techniques and to compute accurate gravitational-waveforms from the system. We will provide accurate, long-lasting simulations, to yield the scalar-instability growth and its subsequent saturation by gravitational wave emission, allowing gravitational-wave templates to be generated. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Black-hole head-on collisionsExploration of head-on collisions in higher-dimensional spacetimes up to about 10 dimensions through numerical investigations using the framework developed in the previous deveriable. Comparison of the numerical results with predictions from shock-wave and point-particle calculations. This study will first explore the equal-mass case with zero initial velocity. Non-vanishing boosts and unequal-mass systems will be explored subsequently to identify the maximum possible loss of kinetic energy in the form of gravitational radiation in ultra-relativistic head-on collisions. Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |
Wave extraction in axisymmetryImplement wave extraction in the form of the higher-dimensional analogue of the Programme: H2020-EU.1.3.3. - Topic(s): MSCA-RISE-2015 |
Documents, reports | 2020-02-26 |