Zobrazeno 1 - 10
of 131
pro vyhledávání: '"H. Völkel"'
Publikováno v:
Frontiers in Astronomy and Space Sciences, Vol 8 (2021)
In this review article, we present the main results from our most recent research concerning the oscillations of fast rotating neutron stars. We derive a set of time evolution equations for the investigation of non-axisymmetric oscillations of rapidl
Externí odkaz:
https://doaj.org/article/ab5d988d74624686a8646124cb0bb24a
Akademický článek
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Publikováno v:
Classical and Quantum Gravity
Following up on a recent analysis by Psaltis et al. [Phys. Rev. Lett. 125, 141104 (2020)], we show that the observed shadow size of M87$^*$ can be used to unambiguously and robustly constrain the black hole geometry in the vicinity of the circular ph
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e10c7b83c21be3555f0177cdeb497529
http://hdl.handle.net/20.500.11767/124871
http://hdl.handle.net/20.500.11767/124871
Autor:
Arthur G. Suvorov, Sebastian H. Völkel
Publikováno v:
Physical Review D
A covariant, scalar-tensor gravity is constructed such that the static, spherically symmetric Rezzolla-Zhidenko metric is an exact solution to the theory. The equations describing gravitational perturbations of this spacetime, which represents a gene
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ddcf429096cbdf9d5989c2da87870097
Autor:
Sebastian H. Völkel, Enrico Barausse
Publikováno v:
Physical Review D
Theories of gravity extending or modifying general relativity typically allow for black hole solutions different from the Schwarzschild/Kerr geometries. Electromagnetic observations have been used to place constraints on parametrized deviations from
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef67034c8b48046be6f1c509270816aa
http://hdl.handle.net/20.500.11767/114733
http://hdl.handle.net/20.500.11767/114733
Publikováno v:
Physical Review D. 100
In this work we study whether parametrized spherically symmetric black hole solutions in metric theories of gravity can appear to be isospectral when studying perturbations. From a theory agnostic point of view, the test scalar field wave equation is
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4b86e76f4d12a74a6191ac8f5f82ffe5
https://doi.org/10.1103/physrevd.100.044026
https://doi.org/10.1103/physrevd.100.044026
In this work we study the inverse problem related to the emission of Hawking radiation. We first show how the knowledge of greybody factors of different angular contributions $l$ can be used to constrain the width of the corresponding black hole pert
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ebbf42a85b61142acfe79366dfdfedb
http://arxiv.org/abs/1902.07611
http://arxiv.org/abs/1902.07611
In this work we revisit axial perturbations of spherically symmetric and non-rotating neutron stars. Although it has been object of many studies, it still offers new insights that are of potential interest for more realistic scenarios or in the study
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7d6d48d71901f1f8487f43f6d9ac3732
Publikováno v:
Einstein Equations: Physical and Mathematical Aspects of General Relativity ISBN: 9783030180607
In this article we present results on the quasi-normal mode spectra of compact relativistic objects and discuss under what conditions they can be used to solve the inverse spectrum problem. We start from the one-dimensional wave equation for axial gr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ba24a710d26f54c6ffcade7d905bb738
https://doi.org/10.1007/978-3-030-18061-4_12
https://doi.org/10.1007/978-3-030-18061-4_12
In this Letter, we study black hole area quantization in the context of gravitational wave physics. It was recently argued that black hole area quantization could be a mechanism to produce so-called echoes as well as characteristic absorption lines i
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::27df068a04d2fbc39749124a1601d867