相关论文: Dynamical Excision Boundaries in Spectral Evolutio…

In this work we explore a numerical technique, based on the spherical harmonic decomposition and the discretization of the radial coordinate through \v{C}eby\v{s}\"ev polynomial interpolation, for the computation of quasi-bound states of…

Worldtube excision is a method of reducing computational burden in Numerical Relativity simulations of binary black holes in situations where there is a good analytical model of the geometry around (one or both of) the objects. Two such…

We explore the hardening of a massive black hole binary embedded in a circum-binary gas disc when the binary and the gas are coplanar and the gas is counter-rotating. The secondary black hole, revolving in the direction opposite to the gas,…

We have developed a new numerical code to study the evolution of distorted, rotating black holes. We discuss the numerical methods and gauge conditions we developed to evolve such spacetimes. The code has been put through a series of tests,…

We introduce a gravitational waveform inversion strategy that discovers mechanical models of binary black hole (BBH) systems. We show that only a single time series of (possibly noisy) waveform data is necessary to construct the equations…

We have recently constructed a numerical code that evolves a spherically symmetric spacetime using a hyperbolic formulation of Einstein's equations. For the case of a Schwarzschild black hole, this code works well at early times, but…

Binary supermassive black holes (SMBH) are expected to form naturally during galaxy mergers. After the dynamical friction phase, when the two SMBHs become gravitationally bound to each other, and a brief stage of initial rapid hardening,…

We compare different methods of computing the orbital eccentricity of quasi-circular binary black hole systems using the orbital variables and gravitational wave phase and frequency. For eccentricities of about a per cent, most methods work…

Recent astrophysical models predict that stellar-mass binary black holes (BBHs) could form and coalesce within a few gravitational radii of a supermassive black hole (SMBH). Detecting the gravitational waves (GWs) from such systems requires…

Accreting supermassive binary black holes (SMBBHs) are potential targets for multi-messenger astronomy as they emit gravitational waves (GW) while their environment emits electromagnetic (EM) waves. In order to get the most out of a joint…

Accurate models of merger remnants are increasingly important for gravitational-wave science, including precision tests of gravity with ringdown, inference of black-hole populations, and modeling hierarchical mergers. For eccentric…

We present an implementation of the dual foliation generalized harmonic gauge (DF-GHG) formulation within the pseudospectral code bamps. The formalism promises to give greater freedom in the choice of coordinates that can be used in…

Simulation of quasicircular compact binaries is a major goal in numerical relativity, as they are expected to constitute most gravitational wave observations. However, given that orbital eccentricity is not well-defined in general…

Accretion disk reflection spectra, including broad iron emission lines, bear the imprints of the strong Doppler shifts and gravitational red-shifts close to black holes. The extremity of these shifts depends on the proximity of the…

The interaction of binary black hole mergers with their environments can be studied using numerical relativity simulations. These start only a short finite time before merger, at which point appropriate initial conditions must be imposed. A…

We present the first results for Cauchy nonlinear evolution of 3D, nonaxisymmetric distorted black holes. We focus on the extraction and verification of 3D waveforms determined by numerical relativity. We show that the black hole evolution…

Black hole binary transients undergo dramatic evolution in their X-ray timing and spectral behaviour during outbursts. In recent years a paradigm has arisen in which "soft" X-ray states are associated with an inner disc radius at, or very…

We show that binary black hole mergers with precessing evolution can potentially excite photons from the quantum vacuum in such a way that total helicity is not preserved in the process. Helicity violation is allowed by quantum fluctuations…

A spectral formulation of the plane-strain boundary integral equations for an interface between dissimilar elastic solids is presented. The boundary integral equations can be written in two equivalent forms: (a) The tractions can be written…

Non-continuous "jumps" of Apparent Horizons occur generically in 3+1 (binary) black hole evolutions. The dynamical trapping horizon framework suggests a spacetime picture in which these "Apparent Horizon jumps" are understood as spatial…