Article
Astronomy & Astrophysics
L. Piro, M. Colpi, J. Aird, A. Mangiagli, A. C. Fabian, M. Guainazzi, S. Marsat, A. Sesana, P. McNamara, M. Bonetti, E. M. Rossi, N. R. Tanvir, J. G. Baker, G. Belanger, T. Dal Canton, O. Jennrich, M. L. Katz, N. Luetzgendorf
Summary: The European Space Agency is studying two large-class missions in the 2030s to investigate energetic and violent phenomena in the Universe. The Athena mission aims to study baryons in large-scale structures and accreting supermassive black holes, while LISA mission extends the hunt for gravitational wave events. The concurrent operation of these missions can enable unique experiments in astrophysics and cosmography.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Multidisciplinary
Romuald A. Janik, Matti Jarvinen, Hesam Soltanpanahi, Jacob Sonnenschein
Summary: This study demonstrates that the domain wall or bubble velocity in a range of strongly coupled theories can be expressed simply using a perfect fluid hydrodynamic formula or equation of state. The predictions for domain wall velocities are tested using the gauge/gravity duality.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Anupreeta More, Surhud More
Summary: As the sensitivity of gravitational wave observatories increases, the possibility of observing strongly lensed pairs of events becomes more real. By utilizing gravitational wave events, we can constrain important astrophysical parameters of the lens system. The development of diagnostics is necessary to robustly identify lensed events. A new statistic based on the joint probability of lensing observables is proposed to discriminate between lensed and unlensed event pairs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jose A. R. Cembranos, Miguel Gonzalez Ortiz, Prado Martin-Moruno
Summary: This paper investigates the phenomenon of graviton-photon oscillation in a cosmological scenario, considering a background cosmic magnetic field and different gravitational frameworks. We find that there exists a damping term that characterizes the attenuation of the conversion probability in cosmological backgrounds, which is a general feature. Additionally, we show that the effects of decoherence caused by interaction with the cosmological expansion and alternative theories of gravity's additional degrees of freedom can be relevant to the phenomenon of graviton-photon mixing.
Article
Astronomy & Astrophysics
Thomas W. Baumgarte, David Hilditch
Summary: This paper compares the performance of shock-avoiding slicing conditions and 1+log slicing for various standard problems and finds that they have similar stability and accuracy, making shock-avoiding slicing a viable alternative to 1+log slicing.
Article
Astronomy & Astrophysics
Theodoros Papanikolaou
Summary: This study gives a first estimate for the primordial black hole (PBH) threshold in the case of a time-dependent equation-of-state parameter. By generalizing the constant parameter prescription and applying it to the QCD phase transition, the study suggests an enhanced PBH production due to the abrupt softening of the equation-of-state parameter.
Article
Astronomy & Astrophysics
Deyan P. Mihaylov, Serguei Ossokine, Alessandra Buonanno, Abhirup Ghosh
Summary: The study introduces a computationally efficient multipolar waveform model that combines numerical-relativity information and equations of two-body dynamics. Comparing to the baseline model, the new model shows a speed-up of one to two orders of magnitude in total mass range, demonstrating high fidelity across the applicable parameter space.
Article
Astronomy & Astrophysics
V Pravda, A. Pravdova, J. Podolsky, R. Svarc
Summary: This study extends a series of non-Einstein solutions for the Schwarzschild black hole and other spacetime structures through the investigation of static spherically symmetric solutions to the vacuum field equations of quadratic gravity. Analysis of ordinary differential equations and power series expansions reveals restrictions on the values of the cosmological constant A, leading to discussions on the physical interpretation of these solutions. The study also introduces the Schwarzschild-Bach-(A)dS black hole, with additional parameters, and examines its thermodynamical properties and effects on test particles.
Article
Astronomy & Astrophysics
Kimmo Kainulainen, Sami Nurmi, Enrico D. Schiappacasse, Tsutomu T. Yanagida
Summary: The study investigates the potential of primordial black holes as sources of fast radio bursts, suggesting that PBHs may release energy through magnetic reconnection during collisions with neutron stars. It also proposes that PBHs could lose energy and be captured by neutron stars during encounters. The results indicate that the parameter space of PBHs as all dark matter is accidentally consistent with the rate of producing fast radio bursts observed.
Article
Astronomy & Astrophysics
Sarp Akcay, Rossella Gamba, Sebastiano Bernuzzi
Summary: TEOBResumSP is introduced as an efficient and accurate hybrid scheme for generating gravitational waveforms from spin-precessing compact binaries. It compares well with current state-of-the-art precessing approximants in terms of frequency-domain matches, highlighting some significant disagreements for large mass ratios and high effective precession parameters. The results suggest that TEOBResumSP is a promising precessing approximant for parameter estimation of generic-spin compact binaries.
Article
Astronomy & Astrophysics
Sebastian J. Szybka, Syed U. Naqvi
Summary: Research shows that in polarized Gowdy cosmology, free masses under the influence of standing gravitational waves are attracted by antinodes and exhibit a velocity memory effect.
Article
Astronomy & Astrophysics
R. A. Konoplya
Summary: The fundamental quasinormal modes of black holes in higher-derivative gravity are moderately corrected by the Weyl term. The first several overtones are highly sensitive to even a relatively small Weyl correction, which might be important when representing the earlier stage of the black hole ringdown. In addition, a problem related to the analytical parametrized approximation of the numerical black hole solution in the Einstein-Weyl theory has been solved by extending the parametrization of the metric to higher orders.
Article
Astronomy & Astrophysics
Jordan Moxon, Mark A. Scheel, Saul A. Teukolsky, Nils Deppe, Nils Vu, Francois Hebert, Lawrence E. Kidder, William Throwe
Summary: This article provides detailed information about the new Cauchy-characteristic evolution (CCE) system in SpECTRE. The implementation is designed to extract waveforms either during the process of a SpECTRE binary compact object simulation or as a stand-alone module from worldtube data provided by another code base. The CCE system, using an improved analytic formulation, eliminates pure-gauge logarithms that would affect the spectral convergence of the scheme. It efficiently extracts all five Weyl scalars, as well as the news and the strain. The SpECTRE CCE system significantly improves modularity, ease of use, and computation speed compared to previous implementations.
Article
Astronomy & Astrophysics
Deborah Ferguson, Karan Jani, Pablo Laguna, Deirdre Shoemaker
Summary: A new criterion has been established to identify the minimum resolution required for numerical relativity simulations to be indistinguishable from real signals. This criterion can be applied to any finite-differencing numerical relativity code with multiple simulations of different resolutions for validation.
Article
Astronomy & Astrophysics
Jung-Wook Kim, Michele Levi, Zhewei Yin
Summary: For the first time, this study investigates all quadratic-in-spin interactions in spinning binaries at the third subleading order in post-Newtonian (PN) gravity, providing observable binding energies and gauge-invariant relations to the angular momentum. The results are applicable to various compact objects, orbits, and spin orientations, and have a significant impact on maximally-rotating objects at the fifth PN order.
