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Bruno C. Mundim

Bio: Bruno C. Mundim is an academic researcher from Rochester Institute of Technology. The author has contributed to research in topics: Numerical relativity & Binary black hole. The author has an hindex of 16, co-authored 28 publications receiving 1697 citations. Previous affiliations of Bruno C. Mundim include Albert Einstein Institution & University of Toronto.

Papers
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Journal ArticleDOI
TL;DR: The Einstein Toolkit as mentioned in this paper is a community-driven, freely accessible computational infrastructure intended for use in numerical relativity, relativistic astrophysics, and other applications, which combines a core set of components needed to simulate astrophysical objects such as black holes, compact objects, and collapsing stars.
Abstract: We describe the Einstein Toolkit, a community-driven, freely accessible computational infrastructure intended for use in numerical relativity, relativistic astrophysics, and other applications. The toolkit, developed by a collaboration involving researchers from multiple institutions around the world, combines a core set of components needed to simulate astrophysical objects such as black holes, compact objects, and collapsing stars, as well as a full suite of analysis tools. The Einstein Toolkit is currently based on the Cactus framework for high-performance computing and the Carpet adaptive mesh refinement driver. It implements spacetime evolution via the BSSN evolution system and general relativistic hydrodynamics in a finite-volume discretization. The toolkit is under continuous development and contains many new code components that have been publicly released for the first time and are described in this paper. We discuss the motivation behind the release of the toolkit, the philosophy underlying its development, and the goals of the project. A summary of the implemented numerical techniques is included, as are results of numerical test covering a variety of sample astrophysical problems.

479 citations

Journal ArticleDOI
TL;DR: The Einstein Toolkit as discussed by the authors is a community-driven, freely accessible computational infrastructure intended for use in numerical relativity, relativistic astrophysics, and other applications, which combines a core set of components needed to simulate astrophysical objects such as black holes, compact objects, and collapsing stars.
Abstract: We describe the Einstein Toolkit, a community-driven, freely accessible computational infrastructure intended for use in numerical relativity, relativistic astrophysics, and other applications. The Toolkit, developed by a collaboration involving researchers from multiple institutions around the world, combines a core set of components needed to simulate astrophysical objects such as black holes, compact objects, and collapsing stars, as well as a full suite of analysis tools. The Einstein Toolkit is currently based on the Cactus Framework for high-performance computing and the Carpet adaptive mesh refinement driver. It implements spacetime evolution via the BSSN evolution system and general-relativistic hydrodynamics in a finite-volume discretization. The toolkit is under continuous development and contains many new code components that have been publicly released for the first time and are described in this article. We discuss the motivation behind the release of the toolkit, the philosophy underlying its development, and the goals of the project. A summary of the implemented numerical techniques is included, as are results of numerical test covering a variety of sample astrophysical problems.

270 citations

Journal ArticleDOI
TL;DR: In this article, the magnetohydrodynamic evolution of a circumbinary disk surrounding an equal-mass binary comprising two non-spinning black holes during the period in which the disk inflow time is comparable to the binary evolution time due to gravitational radiation is described by using high-order post-Newtonian approximations.
Abstract: We have simulated the magnetohydrodynamic evolution of a circumbinary disk surrounding an equal-mass binary comprising two non-spinning black holes during the period in which the disk inflow time is comparable to the binary evolution time due to gravitational radiation. Both the changing spacetime and the binary orbital evolution are described by an innovative technique utilizing high-order post-Newtonian approximations. Prior to the beginning of the inspiral, the structure of the circumbinary disk is predicted well by extrapolation from Newtonian results: a gap of roughly two binary separation radii is cleared, and matter piles up at the outer edge of this gap as inflow is retarded by torques exerted by the binary; the accretion rate is roughly half its value at large radius. During inspiral, the inner edge of the disk initially moves inward in coordination with the shrinking binary, but—as the orbital evolution accelerates—the inward motion of the disk edge falls behind the rate of binary compression. In this stage, the binary torque falls substantially, but the accretion rate decreases by only 10%-20%. When the binary separation is tens of gravitational radii, the rest-mass efficiency of disk radiation is a few percent, suggesting that supermassive binary black holes could be very luminous at this stage of their evolution. Inner disk heating is modulated at a beat frequency comparable to the binary orbital frequency. However, a disk with sufficient surface density to be luminous may be optically thick, suppressing periodic modulation of the luminosity.

164 citations

Journal ArticleDOI
TL;DR: In this paper, the authors have simulated the MHD evolution of a circumbinary disk surrounding an equal-mass non-spinning binary and showed that the structure of the disk is predicted well by extrapolation from Newtonian results.
Abstract: As 2 black holes bound to each other in a close binary approach merger their inspiral time becomes shorter than the characteristic inflow time of surrounding orbiting matter. Using an innovative technique in which we represent the changing spacetime in the region occupied by the orbiting matter with a 2.5PN approximation and the binary orbital evolution with 3.5PN, we have simulated the MHD evolution of a circumbinary disk surrounding an equal-mass non-spinning binary. Prior to the beginning of the inspiral, the structure of the circumbinary disk is predicted well by extrapolation from Newtonian results. The binary opens a low-density gap whose radius is roughly two binary separations, and matter piles up at the outer edge of this gap as inflow is retarded by torques exerted by the binary; nonetheless, the accretion rate is diminished relative to its value at larger radius by only about a factor of 2. During inspiral, the inner edge of the disk at first moves inward in coordination with the shrinking binary, but as the orbital evolution accelerates, the rate at which the inner edge moves toward smaller radii falls behind the rate of binary compression. In this stage, the rate of angular momentum transfer from the binary to the disk slows substantially, but the net accretion rate decreases by only 10-20%. When the binary separation is tens of gravitational radii, the rest-mass efficiency of disk radiation is a few percent, suggesting that supermassive binary black holes in galactic nuclei could be very luminous at this stage of their evolution. If the luminosity were optically thin, it would be modulated at a frequency that is a beat between the orbital frequency of the disk's surface density maximum and the binary orbital frequency. However, a disk with sufficient surface density to be luminous should also be optically thick; as a result, the periodic modulation may be suppressed.

150 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present the new general-relativistic magnetohydrodynamics (GRMHD) capabilities of the Einstein toolkit, an open-source community-driven numerical relativity and computational relativistic astrophysics code.
Abstract: We present the new general-relativistic magnetohydrodynamics (GRMHD) capabilities of the Einstein toolkit, an open-source community-driven numerical relativity and computational relativistic astrophysics code. The GRMHD extension of the toolkit builds upon previous releases and implements the evolution of relativistic magnetized fluids in the ideal MHD limit in fully dynamical spacetimes using the same shock-capturing techniques previously applied to hydrodynamical evolution. In order to maintain the divergence-free character of the magnetic field, the code implements both constrained transport and hyperbolic divergence cleaning schemes. We present test results for a number of MHD tests in Minkowski and curved spacetimes. Minkowski tests include aligned and oblique planar shocks, cylindrical explosions, magnetic rotors, Alfv´ en waves and advected loops, as well as a set of tests designed to study the response of the divergence cleaning scheme to numerically generated monopoles. We study the code’s performance in curved spacetimes with spherical accretion onto a black hole on a fixed background spacetime

142 citations


Cited by
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Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, M. R. Abernathy3  +970 moreInstitutions (114)
TL;DR: This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.
Abstract: We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5 σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4+0.7−0.9×10−22. The inferred source-frame initial black hole masses are 14.2+8.3−3.7M⊙ and 7.5+2.3−2.3M⊙ and the final black hole mass is 20.8+6.1−1.7M⊙. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440+180−190 Mpc corresponding to a redshift 0.09+0.03−0.04. All uncertainties define a 90 % credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

3,448 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, Matthew Abernathy3  +978 moreInstitutions (112)
TL;DR: The first observational run of the Advanced LIGO detectors, from September 12, 2015 to January 19, 2016, saw the first detections of gravitational waves from binary black hole mergers as discussed by the authors.
Abstract: The first observational run of the Advanced LIGO detectors, from September 12, 2015 to January 19, 2016, saw the first detections of gravitational waves from binary black hole mergers. In this paper we present full results from a search for binary black hole merger signals with total masses up to 100M⊙ and detailed implications from our observations of these systems. Our search, based on general-relativistic models of gravitational wave signals from binary black hole systems, unambiguously identified two signals, GW150914 and GW151226, with a significance of greater than 5σ over the observing period. It also identified a third possible signal, LVT151012, with substantially lower significance, which has a 87% probability of being of astrophysical origin. We provide detailed estimates of the parameters of the observed systems. Both GW150914 and GW151226 provide an unprecedented opportunity to study the two-body motion of a compact-object binary in the large velocity, highly nonlinear regime. We do not observe any deviations from general relativity, and place improved empirical bounds on several high-order post-Newtonian coefficients. From our observations we infer stellar-mass binary black hole merger rates lying in the range 9−240Gpc−3yr−1. These observations are beginning to inform astrophysical predictions of binary black hole formation rates, and indicate that future observing runs of the Advanced detector network will yield many more gravitational wave detections.

1,172 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, Matthew Abernathy1  +984 moreInstitutions (116)
TL;DR: The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity.
Abstract: On September 14, 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterise the properties of the source and its parameters. The data around the time of the event were analysed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$ (for each parameter we report the median value and the range of the 90% credible interval). The dimensionless spin magnitude of the more massive black hole is bound to be $0.7$ (at 90% probability). The luminosity distance to the source is $410^{+160}_{-180}$ Mpc, corresponding to a redshift $0.09^{+0.03}_{-0.04}$ assuming standard cosmology. The source location is constrained to an annulus section of $590$ deg$^2$, primarily in the southern hemisphere. The binary merges into a black hole of $62^{+4}_{-4} M_\odot$ and spin $0.67^{+0.05}_{-0.07}$. This black hole is significantly more massive than any other known in the stellar-mass regime.

874 citations

Journal ArticleDOI
TL;DR: This work describes the LALInference software library for Bayesian parameter estimation of compact binary signals, which builds on several previous methods to provide a well-tested toolkit which has already been used for several studies.
Abstract: The Advanced LIGO and Advanced Virgo gravitational-wave (GW) detectors will begin operation in the coming years, with compact binary coalescence events a likely source for the first detections. The gravitational waveforms emitted directly encode information about the sources, including the masses and spins of the compact objects. Recovering the physical parameters of the sources from the GW observations is a key analysis task. This work describes the LALInference software library for Bayesian parameter estimation of compact binary signals, which builds on several previous methods to provide a well-tested toolkit which has already been used for several studies. We show that our implementation is able to correctly recover the parameters of compact binary signals from simulated data from the advanced GW detectors. We demonstrate this with a detailed comparison on three compact binary systems: a binary neutron star, a neutron star–black hole binary and a binary black hole, where we show a cross comparison of results obtained using three independent sampling algorithms. These systems were analyzed with nonspinning, aligned spin and generic spin configurations respectively, showing that consistent results can be obtained even with the full 15-dimensional parameter space of the generic spin configurations. We also demonstrate statistically that the Bayesian credible intervals we recover correspond to frequentist confidence intervals under correct prior assumptions by analyzing a set of 100 signals drawn from the prior. We discuss the computational cost of these algorithms, and describe the general and problem-specific sampling techniques we have used to improve the efficiency of sampling the compact binary coalescence parameter space.

781 citations

Journal ArticleDOI
TL;DR: In this paper, Belitz et al. presented a survey of the state-of-the-art in condensed-matter physics, focusing on the following papers: Condensed Matter Physics (Theoretical) J. IGNACIO CIRAC, Max-Planck-Institut für Quantenoptik Quantum Information RAYMOND E. GOLDSTEIN, University of Cambridge Biological Physics ARTHUR F. HEBARD and DAVID D. KAMIEN.
Abstract: Associate DIETRICH BELITZ, University of Oregon Editors: Condensed Matter Physics (Theoretical) J. IGNACIO CIRAC, Max-Planck-Institut für Quantenoptik Quantum Information RAYMOND E. GOLDSTEIN, University of Cambridge Biological Physics ARTHUR F. HEBARD, University of Florida Condensed Matter Physics (Experimental) RANDALL D. KAMIEN, University of Pennsylvania Soft Condensed Matter DANIEL KLEPPNER, Massachusetts Institute of Technology Atomic, Molecular, and Optical Physics (Experimental) PAUL G. LANGACKER, Institute for Advanced Study, Princeton University Particle Physics (Theoretical) VERA LÜTH, Stanford University Particle Physics (Experimental) DAVID D. MEYERHOFER, University of Rochester Physics of Plasmas and Matter at High-Energy Density WITOLD NAZAREWICZ, University of Tennessee, Oak Ridge National Laboratory Nuclear Physics JOHN H. SCHWARZ, California Institute of Technology Mathematical Physics FRIEDRICH-KARL THIELEMANN, Universität Basel Astrophysics Senior Assistant Editor: DEBBIE BRODBAR, APS Editorial Office American Physical Society

774 citations