Runaway Merging of Black Holes: Analytical Constraint on the Timescale

Mouri, Hideaki; Taniguchi, Yoshiaki

doi:10.1086/339472

Cited by 141 publications

(121 citation statements)

References 26 publications

Supporting

Mentioning

115

Contrasting

Unclassified

Order By: Relevance

“…For a generic PBH mass spectrum, the number of collisions per volume and time is given bȳ To perform our estimate, we assume a very narrow distribution of black hole masses corresponding to a relatively large value of δ in the model (4.1); in this case, we can assume a single value for the mass in the cross section (4.10), see [48,79],…”

Section: Gw From Merging Pbhsmentioning

confidence: 99%

Gravitational waves at interferometer scales and primordial black holes in axion inflation

García-Bellido

Peloso

Ünal

2016

J. Cosmol. Astropart. Phys.

233

287

View full text Add to dashboard Cite

Abstract. We study the prospects of detection at terrestrial and space interferometers, as well as at pulsar timing array experiments, of a stochastic gravitational wave background which can be produced in models of axion inflation. This potential signal, and the development of these experiments, open a new window on inflation on scales much smaller than those currently probed with Cosmic Microwave Background and Large Scale Structure measurements. The sourced signal generated in axion inflation is an ideal candidate for such searches, since it naturally grows at small scales, and it has specific properties (chirality and non-gaussianity) that can distinguish it from an astrophysical background. We study under which conditions such a signal can be produced at an observable level, without the simultaneous overproduction of scalar perturbations in excess of what is allowed by the primordial black hole limits. We also explore the possibility that scalar perturbations generated in a modified version of this model may provide a distribution of primordial black holes compatible with the current bounds, that can act as a seeds of the present black holes in the universe.

show abstract

Section: Gw From Merging Pbhsmentioning

confidence: 99%

Gravitational waves at interferometer scales and primordial black holes in axion inflation

García-Bellido

Peloso

Ünal

2016

J. Cosmol. Astropart. Phys.

233

287

View full text Add to dashboard Cite

show abstract

“…The PBH pair becomes gravitationally bound if the GW emission exceeds the initial kinetic energy. The cross section for this process is [19,20] where M pbh is the PBH mass, and M 30 the PBH mass in units of 30 M , R s = 2GM pbh /c 2 is its Schwarzschild radius, v pbh is the relative velocity of two PBHs, and v pbh−200 is this velocity in units of 200 km sec −1 . We begin with a rough but simple and illustrative estimate of the rate per unit volume of such mergers.…”

mentioning

confidence: 99%

“…The PBH pair becomes gravitationally bound if the GW emission exceeds the initial kinetic energy. The cross section for this process is [19,20] …”

mentioning

confidence: 99%

Did LIGO Detect Dark Matter?

et al. 2016

View full text Add to dashboard Cite

We consider the possibility that the black-hole (BH) binary detected by LIGO may be a signature of dark matter. Interestingly enough, there remains a window for masses 20 M M bh 100 M where primordial black holes (PBHs) may constitute the dark matter. If two BHs in a galactic halo pass sufficiently close, they radiate enough energy in gravitational waves to become gravitationally bound. The bound BHs will rapidly spiral inward due to emission of gravitational radiation and ultimately merge. Uncertainties in the rate for such events arise from our imprecise knowledge of the phase-space structure of galactic halos on the smallest scales. Still, reasonable estimates span a range that overlaps the 2 − 53 Gpc −3 yr −1 rate estimated from GW150914, thus raising the possibility that LIGO has detected PBH dark matter. PBH mergers are likely to be distributed spatially more like dark matter than luminous matter and have no optical nor neutrino counterparts. They may be distinguished from mergers of BHs from more traditional astrophysical sources through the observed mass spectrum, their high ellipticities, or their stochastic gravitational wave background. Next generation experiments will be invaluable in performing these tests.The nature of the dark matter (DM) is one of the most longstanding and puzzling questions in physics. Cosmological measurements have now determined with exquisite precision the abundance of DM [1, 2], and from both observations and numerical simulations we know quite a bit about its distribution in Galactic halos. Still, the nature of the DM remains a mystery. Given the efficacy with which weakly-interacting massive particlesfor many years the favored particle-theory explanationhave eluded detection, it may be warranted to consider other possibilities for DM. Primordial black holes (PBHs) are one such possibility [3-6].Here we consider whether the two ∼ 30 M black holes detected by LIGO [7] could plausibly be PBHs. There is a window for PBHs to be DM if the BH mass is in the range 20 M M 100 M [8,9]. Lower masses are excluded by microlensing surveys [10][11][12]. Higher masses would disrupt wide binaries [9,13,14]. It has been argued that PBHs in this mass range are excluded by CMB constraints [15,16]. However, these constraints require modeling of several complex physical processes, including the accretion of gas onto a moving BH, the conversion of the accreted mass to a luminosity, the self-consistent feedback of the BH radiation on the accretion process, and the deposition of the radiated energy as heat in the photon-baryon plasma. A significant (and difficult to quantify) uncertainty should therefore be associated with this upper limit [17], and it seems worthwhile to examine whether PBHs in this mass range could have other observational consequences.In this Letter, we show that if DM consists of ∼ 30 M BHs, then the rate for mergers of such PBHs falls within the merger rate inferred from GW150914. In any galactic halo, there is a chance two BHs will undergo a hard scatter, lose energy to a s...

show abstract

“…Previous studies have suggested that interactions in this dense cluster can produce many BH-BH mergers, whether through evaporated binaries [4] or through runaway BH-BH mergers in the dense cluster itself [30,31,32]. However, these studies have faced significant objections to their details, because each has omitted some feature which could significantly inhibit the channel suggested.…”

mentioning

confidence: 99%

Dynamical interactions and the black-hole merger rate of the Universe

2007

View full text Add to dashboard Cite

Binary black holes can form efficiently in dense young stellar clusters, such as the progenitors of globular clusters, via a combination of gravitational segregation and cluster evaporation. We use simple analytic arguments supported by detailed N -body simulations to determine how frequently black holes born in a single stellar cluster should form binaries, be ejected from the cluster, and merge through the emission of gravitational radiation. We then convolve this "transfer function" relating cluster formation to black hole mergers with (i) the distribution of observed cluster masses and (ii) the star formation history of the universe, assuming that a significant fraction g cl of star formation occurs in clusters and that a significant fraction gevap of clusters undergo this segregation and evaporation process. We predict future ground-based gravitational wave (GW) detectors could observe ∼ 500(g cl /0.5)(gevap/0.1) double black hole mergers per year, and the presently operating LIGO interferometer would have a chance (50%) at detecting a merger during its first full year of science data. More realistically, advanced LIGO and similar next-generation gravitational wave observatories provide unique opportunities to constrain otherwise inaccessible properties of clusters formed in the early universe.PACS numbers: 04.30. Db, 95.55.Ym, and 97.60.Lf Given our understanding of how isolated binary stars evolve, noninteracting stellar systems should produce relatively few double black hole (BH-BH) binaries tight enough to merge through the emission of GW within the age of the universe [1,2,3]. Portegies Zwart and McMillan [4] demonstrated that interactions between black holes (BHs) in dense cluster environments could produce merging BH-BH binaries much more efficiently than through the evolution of isolated binaries. As a result, the local binary black hole merger rate -the net rate both from isolated evolution of noninteracting stars and from dense clusters -can depend sensitively on the formation and evolution of young clusters through the entire history of the universe.An increasing number of galactic [5,6] and extragalactic [7,8] observations suggest at least 20% of stars form in dense, interacting stellar clusters. Over time, each cluster dissipates, both because hot young stars and supernovae (SN) heat and eject a significant fraction of the residual gas that gravitationally binds the cluster ("infant mortality"), and because the host galaxy's tidal field strips off stars as the cluster orbits it [9,10]. Thus any set of coeval clusters decrease in number and size, spewing stars into their hosts [11,12], with only a few of the most initially dense and orbitally-fortunate clusters surviving to the present.Unfortunately, electromagnetic observations of large young clusters in other galaxies cannot resolve their internal structure. These observations therefore only weakly constrain the fraction of young clusters that survive their first few Myr, during which the most massive young stars evolve, supernovae, and g...

show abstract

Runaway Merging of Black Holes: Analytical Constraint on the Timescale

Cited by 141 publications

References 26 publications

Gravitational waves at interferometer scales and primordial black holes in axion inflation

Gravitational waves at interferometer scales and primordial black holes in axion inflation

Did LIGO Detect Dark Matter?

Dynamical interactions and the black-hole merger rate of the Universe

Contact Info

Product

Resources

About