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It is known that a near-extremal Kerr black hole can be spun up beyond its extremal limit by capturing a test particle. Here we show that overspinning is always averted once backreaction from the particle's own gravity is properly taken into account. We focus on nonspinning, uncharged, massive particles thrown in along the equatorial plane and work in the first-order self-force approximation (i.e., we include all relevant corrections to the particle's acceleration through linear order in the ratio, assumed small, between the particle's energy and the black hole's mass). Our calculation is a numerical implementation of a recent analysis by two of us [Phys. Rev. D 91, 104024 (2015)], in which a necessary and sufficient "censorship" condition was formulated for the capture scenario, involving certain self-force quantities calculated on the one-parameter family of unstable circular geodesics in the extremal limit. The self-force information accounts both for radiative losses and for the finite-mass correction to the critical value of the impact parameter. Here we obtain the required self-force data and present strong evidence to suggest that captured particles never drive the black hole beyond its extremal limit. We show, however, that, within our first-order self-force approximation, it is possible to reach the extremal limit with a suitable choice of initial orbital parameters. To rule out such a possibility would require (currently unavailable) information about higher-order self-force corrections. [ABSTRACT FROM AUTHOR]

We study the scenario in which a massive particle is thrown into a rapidly rotating Kerr black hole in an attempt to spin it up beyond its extremal limit, challenging weak cosmic censorship. We work in black-hole perturbation theory, and focus on nonspinning, uncharged particles sent in on equatorial orbits. We first identify the complete parameter-space region in which overspinning occurs when backreaction effects from the particle's self-gravity are ignored. We find, in particular, that overspinning can be achieved only with particles sent in from infinity. Gravitational self-force effects may prevent overspinning by radiating away a sufficient amount of the particle's angular momentum ("dissipative effect"), and/or by increasing the effective centrifugal repulsion, so that particles with suitable parameters never get captured ("conservative effect"). We analyze the full effect of the self-force, thereby completing previous studies by Jacobson and Sotiriou (who neglected the self-force) and by Barausse, Cardoso and Khanna (who considered the dissipative effect on a subset of orbits). Our main result is an inequality, involving certain self-force quantities, which describes a necessary and sufficient condition for the overspinning scenario to be overruled. This "censorship" condition is formulated on a certain one-parameter family of geodesics in the limit of an extremal Kerr geometry. We find that the censorship condition is insensitive to the dissipative effect (within the first-order self-force approximation used here), except for a subset of perfectly fine-tuned orbits, for which a separate censorship condition is derived. We do not obtain here the self-force input needed to evaluate either of our two conditions, but discuss the prospects for producing the necessary data using state-of-the-art numerical codes. [ABSTRACT FROM AUTHOR]

Using the results of Cacciatori, Klemm, Mansi, and Zorzan [J. High Energy Phys. 05 (2008) 097], where all timelike supersymmetric backgrounds of N = 2, D = 4 matter-coupled supergravity with Fayet-Iliopoulos gauging were classified, we construct genuine NUT-charged BPS black holes in anti-de Sitter4 with nonconstant moduli. The calculations are exemplified for die SU(1, 1)/U(1) model with prepotential F = --iX0X1. The resulting supersymmetric black holes have a hyperbolic horizon and carry two electric, two magnetic, and one NUT charge, which are however not all independent, but are given in terms of three free parameters. We find that turning on a NUT charge lifts the flat directions in the effective black hole potential, such that the horizon values of the scalars are completely fixed by the charges. We also oxidize the solutions to 11 dimensions, and find that they generalize the geometry found in the work of Gauntlett, Kim, Pakis, and Waldram [Phys. Rev. D 65, 026003 (2001)] corresponding to membranes wrapping holomorphic curves in a Calabi-Yau fivefold. Finally, a class of NUT-charged Nernst branes is constructed as well, but these have curvature singularities at the horizon. [ABSTRACT FROM AUTHOR]

We reanalyze the gravitational-wave event GW190412 with state-of-the-art phenomenological waveform models. This event, which has been associated with a black hole merger, is interesting due to the significant contribution from subdominant harmonics. We use both frequency-domain and time-domain waveform models. The PhenomX waveform models constitute the fourth generation of frequency-domain phenomenological waveforms for black hole binary coalescence; they have more recently been complemented by the time-domain PhenomT models, which open up new strategies to model precession and eccentricity, and to perform tests of general relativity with the phenomenological waveforms approach. Both PhenomX and PhenomT have been constructed with similar techniques and accuracy goals, and due to their computational efficiency this "generation X" model family allows the routine use of subdominant spherical harmonics in Bayesian inference. We show the good agreement between these and other state-of-the-art waveform models for GW190412, and discuss the improvements over the previous generation of phenomenological waveform models. We also discuss practical aspects of Bayesian inference such as run convergence, variations of sampling parameters, and computational cost. [ABSTRACT FROM AUTHOR]

We present the imrphenomxhm frequency domain phenomenological waveform model for the inspiral, merger, and ringdown of quasicircular nonprecessing black hole binaries. The model extends the imrphenomxas waveform model [G. Pratten, S. Husa, C. García-Quirós, M. Colleoni, A. Ramos-Buades, H. Estellés, and R. Jaume, preceding paper, Phys. Rev. D 102, 064001 (2020)], which describes the dominant quadrupole modes l=|m|=2, to the harmonics (l,|m|)=(2,1),(3,3),(3,2),(4,4), and includes mode mixing effects for the (3,2) spherical harmonic. imrphenomxhm is calibrated against hybrid waveforms, which match an inspiral phase described by the effective-one-body model and post-Newtonian amplitudes for the subdominant harmonics to numerical relativity waveforms and numerical solutions to the perturbative Teukolsky equation for large mass ratios up to 1000. [ABSTRACT FROM AUTHOR]

For a Schwarzchild black hole of mass M, we consider a test particle falling from rest at infinity and becoming trapped, at late time, on the unstable circular orbit of radius r=4GM/c². When the particle is endowed with a small mass, μ≪M, it experiences an effective gravitational self-force, whose conservative piece shifts the critical value of the angular momentum and the frequency of the asymptotic circular orbit away from their geodesic values. By directly integrating the self-force along the orbit (ignoring radiative dissipation), we numerically calculate these shifts to O(μ/M). Our numerical values are found to be in agreement with estimates first made within the effective one-body formalism and with predictions of the first law of black-hole-binary mechanics (as applied to the asymptotic circular orbit). Our calculation is based on a time-domain integration of the Lorenz-gauge perturbation equations, and it is a first such calculation for an unbound orbit. We tackle several technical difficulties specific to unbound orbits, illustrating how these may be handled in more general cases of unbound motion. Our method paves the way to calculations of the self-force along hyperbolic-type scattering orbits. Such orbits can probe the two-body potential down to the "light ring" and could thus supply strong-field calibration data for eccentricity-dependent terms in the effective one-body model of merging binaries. [ABSTRACT FROM AUTHOR]

We present imrphenomxphm, a phenomenological frequency-domain model for the gravitational-wave signal emitted by quasicircular precessing binary black holes, which incorporates multipoles beyond the dominant quadrupole in the precessing frame. The model is a precessing extension of imrphenomxhm, [C. García-Quirós et al., Phys. Rev. D 102, 064002 (2020)] based on approximate maps between aligned-spin waveform modes in the coprecessing frame and precessing waveform modes in the inertial frame, which is commonly referred to as "twisting up" the nonprecessing waveforms. imrphenomxphm includes imrphenomxp as a special case, the restriction to the dominant quadrupole contribution in the coprecessing frame. We implement two alternative mappings, one based on a single-spin post-Newtonian approximation, as used in imrphenompv2 [M. Hannam et al., Phys. Rev. Lett. 113, 151101 (2014).], and one based on the double-spin multiple scale analysis approach of [K. Chatziioannou et al., Phys. Rev. D 95, 104004 (2017).]. We include a detailed discussion of conventions used in the description of precessing binaries and of all choices made in constructing the model. The computational cost of imrphenomxphm is further reduced by extending the interpolation technique of [C. García-Quirós et al., Classical Quant. Grav. 38, 015006 (2021).] to the Euler angles. The accuracy, speed, robustness, and modularity of the imrphenomx family will make these models productive tools for gravitational wave astronomy in the current era of greatly increased number and diversity of detected events. [ABSTRACT FROM AUTHOR]

In this work we present IMRPhenomTP, a time domain phenomenological model for the dominant l=2, m=|2| modes of coalescing black hole binary systems and its extension to describe general precessing systems within the "twisting up" approximation. The underlying nonprecessing model, IMRPhenomT, is calibrated to the new release of numerical relativity simulations of the SXS Collaboration and its accuracy is comparable to the state-of-the-art nonprecessing dominant mode models as IMRPhenomX and SEOBNRv4. The precessing extension allows for flexibility choosing the Euler angles of the time-dependent rotation between the coprecessing and the inertial reference systems, including the single spin next-to-next-to-leading order and the double spin multiscale analysis post-Newtonian descriptions present in other models, numerical integration of the orbit averaged spin evolution equations, different choices for the evolution of the orbital angular momentum norm, and a simple approximation to the ringdown behavior. [ABSTRACT FROM AUTHOR]

In this paper we present imrphenomxas, a thorough overhaul of the imrphenomd [S. Husa et al., Phys. Rev. D 93, 044006 (2016); S. Khan et al., Phys. Rev. D 93, 044007 (2016)] waveform model, which describes the dominant l=2, |m|=2 spherical harmonic mode of nonprecessing coalescing black holes in terms of piecewise closed form expressions in the frequency domain. Improvements include in particular the accurate treatment of unequal spin effects, and the inclusion of extreme mass ratio waveforms. imrphenomd has previously been extended to approximately include spin precession [M. Hannam et al., Phys. Rev. Lett. 113, 151101 (2014)] and subdominant spherical harmonics [L. London et al., Phys. Rev. Lett. 120, 161102 (2018)], and with its extensions it has become a standard tool in gravitational wave parameter estimation. Improved extensions of imrphenomxas are discussed in companion papers [C. García-Quirós et al., Phys. Rev. D 102, 064002 (2020); G. Pratten et al., arXiv:2004.06503]. [ABSTRACT FROM AUTHOR]

We analyze a new numerical relativity dataset of spinning but nonprecessing binary black holes on eccentric orbits, with eccentricities from approximately 0.1 to 0.5, with dimensionless spins up to 0.75 included at mass ratios q=m1/m2=(1,2), and further nonspinning binaries at mass ratios q=(1.5,3,4). A comparison of the final mass and spin of these simulations with noneccentric data extends previous results in the literature on circularization of eccentric binaries to the spinning case. For the (l,m)=(2,2) spin-weighted spherical harmonic mode, we construct eccentric hybrid waveforms that connect the numerical relativity data to a post-Newtonian description for the inspiral, and we discuss the limitations in the current knowledge about post-Newtonian theory which complicate the generation of eccentric hybrid waveforms. We also perform a Bayesian parameter estimation study, quantifying the parameter biases introduced when using three different quasicircular waveform models to estimate the parameters of highly eccentric binary systems. We find that the used aligned-spin quasicircular model including higher order modes produces lower bias in certain parameters than the nonprecessing quasicircular model without higher order modes and the quasicircular precessing model. [ABSTRACT FROM AUTHOR]

We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spin-aligned) and tidally interacting compact binaries. Spin-orbit and spin-spin effects are blended together by making use of the concept of centrifugal EOB radius. The point-mass sector through merger and ringdown is informed by numerical relativity (NR) simulations of binary black holes (BBHs) computed with the SpEC and bam codes. An improved, NR-based phenomenological description of the postmerger waveform is developed. The tidal sector of TEOBResumS describes the dynamics of neutron star binaries up to merger and incorporates a resummed attractive potential motivated by recent advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. Equation-of-state-dependent self-spin interactions (monopole-quadrupole effects) are incorporated in the model using leading order post-Newtonian results in a new expression of the centrifugal radius. TEOBResumS is compared to 135 SpEC and 19 bam BBH waveforms. The maximum unfaithfulness to SpEC data F¯--at design Advanced LIGO sensitivity and evaluated with total mass M with a variance of 10M⊙≤M≤200M⊙--is always below 2.5×10-3 except for a single outlier that grazes the 7.1×10-3 level. When compared to bam data, F¯ is smaller than 0.01 except for a single outlier in one of the corners of the NR-covered parameter space that reaches the 0.052 level. TEOBResumS is also compatible, up to merger, to high-end NR waveforms from binary neutron stars with spin effects and reduced initial eccentricity computed with the bam and thc codes. The data quality of binary neutron star waveforms is assessed via rigorous convergence tests from multiple resolution runs and takes into account systematic effects estimated by using the two independent high-order NR codes. The model is designed to generate accurate templates for the analysis of LIGO-Virgo data through merger and ringdown. We demonstrate its use by analyzing the publicly available data for GW150914. [ABSTRACT FROM AUTHOR]