广义相对论与量子宇宙学
We investigate the dynamics of massive test particles around a static black hole in nonlocal gravity and examine the corresponding properties of HF QPOs, constraining the nonlocal parameter to $\alpha/M \leq 0.452$. The nonlocal parameter…
Early-time evolution away from an unstable equilibrium in a nonlinear system is often expected to be governed by the associated linear instability. Combining full nonlinear evolution with first- and second-order quasinormal mode (QNM)…
Low-latency gravitational-wave search pipelines provide early-warning alerts for multimessenger astrophysical transients. Current pipelines whiten the data stream using acausal, linear-phase filters, which require a look-ahead buffer that…
We present a unified analysis of the linear evolution of peculiar-velocity perturbations in the distribution of pressureless matter after recombination. Our study is carried out within the framework of full general relativity and…
We study the analytic properties and three equivalent representations of the Toller matrices $T^{(\pm)}$ which appear in the causal formulation of spinfoam transition amplitudes for 4d Lorentzian quantum gravity. These are polynomially…
The purpose of this work is to discuss how matter fields are coupled to gravity within the framework of General Relativity. Our particular focus here is on the coupling of scalar field models. In a first step, we suggest a new method for…
We provide a formulation of the initial boundary value problem for Friedrich's extended conformal Einstein field equations in which boundary data is prescribed on a timelike hypersurface located at a finite position in the spacetime. Our…
Spontaneous scalarization phenomenon in scalar-tensor gravity is known to be a form of phase transition, and it was recently shown that the order of this transition changes depending on the parameters of the theory. There exists a…
We investigate Hawking-like particle production in analogue gravity systems with superluminal modified dispersion relations. For a broad class of even, convex, and polynomially bounded dispersion relations, we show that the relevant…
We obtained quasinormal modes and greybody factors of the quantum Oppenheimer-Snyder (QOS) black hole with quintessential dark energy and string clouds. We compute the effective potentials of the scalar and the vector perturbation fields…
We investigate whether retarded scalar propagators on causal sets can be expressed in terms of the link matrix $\mathbf{L}$. For Poisson sprinklings into $1+1$ dimensional Minkowski spacetime, we show by asymptotic analysis and supporting…
The evolution equation of the Szekeres metrics allows solutions with the mass function $M < 0$. They exist in both classes of the Szekeres metrics, have no Big Bang singularity and no origin. In both classes, the conditions for no shell…
Bounds for the area of general closed marginally trapped surfaces (MTSs) are presented. They do not require any stability condition, and are determined by a constant that depends on a particular component of the Einstein tensor on the…
Using the worldline action in [2409.05860], we derive the total even-in-velocity (relative) impulse, scattering angle, and time delay at fifth post-Newtonian (5PN) order, including radiation-reaction and hereditary contributions at ${\cal…
In this work, we investigate the structure of black hole shadows in the bumblebee gravity model formulated within the metric-affine framework, which incorporates spontaneous Lorentz symmetry breaking (LSB) through a vector field $B_\mu$…
We investigate the decoherence of an Unruh-DeWitt detector coupled to scalar, electromagnetic, and spinor fields in four-dimensional Minkowski spacetime. By employing the Schwinger-Keldysh influence functional formalism, we derive a…
We show that, within a broad stationary-axisymmetric class, Kerr-type separability and hidden symmetry arise as a local consequence of the Einstein equations. Without assuming separability, algebraic speciality, Killing--Yano symmetry, or…
In this work, we investigate the ppE waveform imprints induced by the external magnetic fields of Bertotti-Robinson and Bonnor-Melvin black holes, with the aim of distinguishing such magnetic effects from environmental influences. We first…
GW231123 is an exceptional gravitational-wave event consistent with the merger of two massive, highly-spinning black holes. Reliable inference of the source properties is crucial for accurate interpretation of its astrophysical…
The Laser Interferometer Space Antenna (LISA) is expected to have a source rich data stream containing signals from large numbers of many different types of source. This will include both individually resolvable signals and overlapping…