Gravitational Theory
ABOUT OUR RESEARCH
Our research is focused on general relativity and its applications in astrophysics and geodesy as well as relations to quantum physics. This includes astrophysical extreme mass ratio systems and accretion disks around black holes as well as investigations of relativistic effects on the motion of satellites. The relativistic effects in rates of clocks on Earth and in space are crucial e.g. for height determination in geodesy. Moreover, we study fundamental problems in electrodynamics and in alternative theories of gravity.
Our fields of research
- Dynamics of light, particles (stars), and fluids in relativistic spacetimes using mostly analytical techniques
- Applications in relativistic astrophysics: extreme mass ratio systems, pulsar timing, accretion disks, gravitational lensing
- Tests of gravity: investigation of relativistic effects on satellites orbiting the Earth as well as Earth- or space-based clocks
- Relativistic geodesy: basic notions in General Relativity (GR), new concepts using the additional gravity degrees of freedom in GR; related topics are synchronisation and geodetic reference frames
- Alternative/modified theories of gravity and electrodynamics
CONTACT
The QuantumFrontiers program explores light and matter at the quantum frontier, advancing quantum and nanometrology to enhance measurement precision. These innovations enable groundbreaking technologies, from probing gravitational waves to understanding quantum-scale phenomena, deepening our knowledge of nature at both cosmic and microscopic scales.
The long term vision of TerraQ is to create a new geodesy based on quantum physics and general relativity, enabling unique prospects for satellite geodesy, gravimetric Earth observation and reference systems.
This research unit develops methods to enhance geodetic reference systems by linking all space geodetic techniques to a common time system. Accurate, stable global reference frames are essential for positioning, navigation, and understanding long-term geodynamic and climate processes, including plate tectonics and sea-level change.
This COST Action Network brings together theorists and experimentalists to explore the regime where gravity meets quantum physics. From astrophysical observations to precision table-top experiments, the aim is to understand Planck-scale effects and study gravity's influence on quantum systems, bridging expertise in quantum-gravity, -optics, -mechanics, and high-energy astrophysics.
DFG Project 'Momentum dependent spacetime geometries: Traces of quantum gravity and fields in media'
This project establishes a rigorous mathematical framework for effective quantum spacetime geometries using Finsler and Hamilton geometry. It seeks to derive observable predictions (e.g., particle trajectories, time delays, light deflections), study classical and quantum field propagation on quantum spacetime, and develops the dynamics that determine the quantum spacetime geometry.
Accretion disks around black holes and neutron stars, shaped by electromagnetic fields, provide insights into strong-gravity regimes. This project explores charged fluid disks, focusing on their self-interactions through analytic models and GRMHD simulations, aiming to unravel complex phenomena in disk structure, physics, and evolution near compact objects.
The list below shows the latest 25 publications of this research group. For the complete, searchable list of ZARM publications, please click more
2017
Conservation laws and evolution schemes in geodesic, hydrodynamic and magnetohydrodynamic flows
Phys. Rev. D, 96 :064019
2017
The Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science
Foundations of Physics, 47 :553
2017
2016
Generalized deviation equation and determination of the curvature in General Relativity
Phys. Rev. D, 93 :044073
2016
Dynamics of test bodies in scalar-tensor theory and equivalence principle
Gravitation, Astrophysics, and Cosmology - Proceedings of the Twelfth Asia-Pacific International Conference, Moscow, 28 Jun - 5 July 2015, Eds. V. Melnikov and J.-P. Hsu, World Scientific (Singapore), 2016, pp. 231-235
2016
Comparing Hamiltonians of a spinning test particle for different tetrad fields
Phys. Rev. D, 93 :044004
2016
Canonical Hamiltonian for an extended test body in curved spacetime: To quadratic order in spin
Phys. Rev. D, 93 :103008
2016
The shadow of black holes
2016
On causality in nonlinear vacuum electrodynamics of the Plebanski class
Ann. Phys. (Berlin), 528 :738–749
2016
Anisotropic inflation in Gauss-Bonnet gravity
J. Cosmol. Astrop. Phys., 2016 (09) :025
2016
Circular motion in NUT spacetime
Class. Quantum Grav., 33 :245014
2016
Parameters of innermost stable circular orbits of spinning test particles: Numerical and analytical calculations
Gravitation and Cosmology, 22 :138-147
2016
Strong lensing by fermionic dark matter in galaxies
Phys. Rev. D, 94 :123004
2016
2015
Schwarzschild radial perturbations in Eddington-Finkelstein and Painlevé-Gullstrand coordinates
Int. J. Mod. Phys. D, 24 :1542006
2015
Isofrequency pairing of spinning particles in Schwarzschild-de Sitter spacetime
Phys. Rev. D, 92 :024029
2015
Photon regions and shadows of accelerated black holes
Int. J. Mod. Phys. D, 24 :1542024
2015
Testing non-linear vacuum electrodynamics with Michelson interferometry
Phys. Rev. D, 92 :025039
2015
Jet signatures of black holes: From Sgr A* to active galactic nuclei
Astron. Nachr., 336 :471
2015
On the self-force in Bopp-Podolsky electrodynamics
J. Phys. A, 48 :435401
2015
Influence of a plasma on the shadow of a spherically symmetric black hole
Phys. Rev. D, 92 :104031
2015
The galactic center black hole laboratory
"Equations of Motion in Relativistic Gravity", D. Puetzfeld et. al. (eds.), Fundamental theories of Physics, 179, pages 759-781, Springer 2015
2015
Multipolar test body equations of motion in generalized gravity theories
"Equations of Motion in Relativistic Gravity", D. Puetzfeld et. al. (eds.), Fundamental theories of Physics 179, pages 67-119, Springer 2015
2015
Equivalence principle in scalar-tensor gravity
Phys. Rev. D, 92 :081502(R)
2015
Invariant conserved currents in generalized gravity
Phys. Rev. D, 92 :104010
2015
Motion of test particles in a regular black hole space–time
J. Math. Phys., 56 :032501
2015
2014
Photon regions and shadows of Kerr-Newman-NUT black holes with a cosmological constant
Phys. Rev. D, 89 :124004
2014