Simulation of the gravitational wave frequency distribution of neutron star-black hole mergers

LIGO-Virgo has observed the gravitational waves(GWs)from the coalescence of binary black hole(BBH)and binary neutron star(BNS)during O1 and O2,and the ones from NS-BH are expected to be hunted in the operating O3 run.The population properties and mass distribution of NS-BH mergers are poorly understood now,thus researchers simulated their chirp mass(M)distribution by a synthetic model,in which the BHs and NSs were inferred by LIGO-Virgo(O1/O2),and obtained the values in the range of 2.1 M_(⊙)<M<7.3 M_(⊙).In this paper,we further simulate the GW frequency(fGW)distribution of NS-BH mergers by the above-stated synthetic model,with a basic binary system model through the Monte Carlo method.Our results predict that the median with 90%credible intervals is 165+475-64 Hz in the case of Schwarzschild BH when the system just before merger,and this GW frequency is expected to increase several times in the merger stage,which is lying in the frequency band of LIGO-Virgo,i.e.,about 15 Hz to a few kHz.Our results provide an important reference for hunting the NS-BH mergers by the on-going O3 run of LIGO-Virgo.

Looking at the Physics of What a Quark Star-Black Hole Binary Would Create in Terms of GW Signals and New Physics

A quark star, black hole pairing as a would-be Gravitational wave generator is brought up. Quark stars are, anyway, likely to be black holes, above a certain mass limit, whereas a quark star in itself obey thermodynamic “laws” which in certain ways differ from the traditional black hole models. We list some of the probable consequences of such a binary, and make predictions as to certain GW phenomenon which will have observational consequences. i.e., a GW “change in energy” from a black hole—Quark star pair would likely be within 90% of that of comparatively massed black hole—black hole binary pair. The electromagnetic “profile” of the two cases would differ dramatically, and we conclude our inquiry with an open question if a generalized uncertainty principle could play a role in comparing the 7th and 8th equations of our presentation.

A global analysis searching for neutrinos associated with black hole merger gravitational wave events

Several neutrino observatories have searched for coincident neutrino signals associated with gravitational waves induced by the merging of two black holes. No statistically significant neutrino signal in excess of the background level was observed. These experiments use different neutrino detection technologies and are sensitive to various neutrino types. A combined analysis was performed on the KamLAND, Super-Kamiokande and Borexino experimental data with a frequentist statistical approach to achieve a global picture of the associated neutrino fluence. Both monochromatic and Fermi-Dirac neutrino spectra were assumed in the calculation. The final results are consistent with null neutrino signals associated with the process of a binary black hole merger. The derived 90% confidence level upper limits on the fluence and luminosity of various neutrino types are presented for neutrino energy less than110 MeV.

Formation of Galaxies in the Context of Gravitational Waves and Primordial Black Holes

The recent discovery of gravitational waves has revolutionized our understanding of many aspects regarding how the universe works. The formation of galaxies stands as one of the most challenging problems in astrophysics. Regardless of how far back we look in the early universe, we keep discovering galaxies with supermassive black holes lurking at their centers. Many models have been proposed to explain the rapid formation of supermassive black holes, including the massive accretion of material, the collapse of type III stars, and the merger of stellar mass black holes. Some of these events give rise to the production of gravitational waves that could be detected by future generations of more sensitive detectors. Alternatively, the existence of these supermassive black holes can be explained in the context of primordial black holes. In this paper we discuss the various models of galaxy formation shedding light on the role that gravitational waves can play to test of the validity of some of these models. We also discuss the prospect of primordial black holes as a seeding constituent for galaxy formation.

How a Laser Physics Induced Kerr-Newman Black Hole Can Release Gravitational Waves without Igniting the Black Hole Bomb (Explosion of a Mini Black Hole in a Laboratory)

Note, that micro black holes last within micro seconds, and that we wish to ascertain how to build, in a laboratory, a black hole, which may exist say at least up to 10^?1 seconds and provide a test bed as to early universe gravitational theories. First of all, it would be to determine, if the mini black hole bomb, would spontaneously occur, unless the Kerr-Newmann black hole were carefully engineered in the laboratory. Specifically, we state that this paper is modeling the creation of an actual Kerr Newman black hole via laser physics, or possibly by other means. We initiate a model of an induced Kerr-Newman black Holes, with specific angular momentum J, and then from there model was to what would happen as to an effective charge, Q, creating an E and B field, commensurate with the release of GWs. The idea is that using a frame of reference trick, plus E + i B = ?function of the derivative of a complex valued scalar field, as given by Appell, in 1887, and reviewed by Whittaker and Watson, 1927 of their “A Course of Modern Analysis” tome that a first principle identification of a B field, commensurate with increase of thermal temperature, T, so as to have artificially induced GW production. This is compared in part with the Park 1955 paper of a spinning rod, producing GW, with the proviso that both the spinning rod paper, and this artificial Kerr-Newman Black hole will employ the idea of lasers in implementation of their respective GW radiation. The idea is in part partly similar to an idea the author discussed with Dr. Robert Baker, in 2016 with the difference that a B field would be generated and linked to effects linked with induced spin to the Kerr-Newman Black hole. We close with some observations about the “black holes have no hair” theorem, and our problem. Citing some recent suppositions that this “theorem” may not be completely true and how that may relate to our experimental situation. We close with observations from Haijicek, 2008 as which may be pertinent to Quantization of Gravity. Furthermore as an answer to questions raised by a referee, we will have a final statement as to how this problem is for a real black hole being induced, and answering his questions in his review, which will be included in a final appendix to this paper. The main issue which is now to avoid the black hole bomb effect which would entail an explosion of a small black hole in a laboratory. Furthermore as an answer to questions raised by a referee, we will have a final statement as to how this problem is for a real black hole being induced, and answering his questions in his review, which will be included in a final appendix to this paper. In all, the main end result is to try to avoid the so called black hole bomb effect, where a mini black hole would explode in a laboratory setting within say 10^?16 or so seconds, i.e. the idea would be to have a reasonably stable configuration within put laser energy, but a small mass, and to do it over hopefully 10^15 or more times longer than the 10^?16 seconds where the mini black hole would quickly evaporate. I.e. a duration of say up to 10^?1 seconds which would provide a base line as to astrophysical modeling of a Kerr-Newman black hole.

Gravitational wave echoes from strange quark stars in the equation of state with density-dependent quark masses

According to the recent studies,the gravitational wave(GW)echoes are expected to be generated by quark stars composed of ultrastiff quark matter.The ultrastiff equations of state(EOS)for quark matter were usually obtained either by a simple bag model with artificially assigned sound velocity or by employing interacting strange quark matter(SQM)depicted by simple reparameterization and rescaling.In this study,we investigate GW echoes with EOSs for SQM in the framework of the equivparticle model with density-dependent quark masses and pairing effects.We conclude that strange quark stars(SQSs)can be sufficiently compact to possess a photon sphere capable of generating GW echoes with frequencies in the range of approximately 20 kHz.However,SQSs cannot account for the observed 72 Hz signal in GW170817 event.Furthermore,we determined that quark-pairing effects play a crucial role in enabling SQSs to satisfy the necessary conditions for producing these types of echoes.

Quenched Galaxies are Important Host Candidates of Binary Black Hole and Binary Neutron Star Mergers

In this work,we present the probabilities of mergers of binary black holes(BBHs)and binary neutron stars(BNSs)as functions of stellar mass,metallicity,specific star formation rate(sSFR),and age for galaxies with redshift z≤0.1.Using the binary-star evolution(BSE)code and some fitting formulae,we construct a phenomenological model of cosmic gravitational wave(GW)merger events.By using the Bayesian analysis method and the observations from Advanced LIGO and Virgo,we obtain the relevant parameters of the phenomenological model(such as the maximum black hole mass is 93_(-22)^(+73)M_(⊙)).Combining the above model results with the galaxy catalog given by the EMERGE empirical galaxy model,we find the normalized probability of occurrence of a merger event varying with log10 sSFR yr(-1)for galaxies with z≤0.1 is different from that in previous studies,that is,two peaks exist in this work while there is only one peak(log_(10)(sSFR/yr^(−1))=−10)in the previous work.The sSFR value corresponding to the new peak is log_(10)(sSFR/yr^(−1))=−12 and in line with the value(log_(10)(sSFR yr^-1)=-12.65_(-0.66)^(+0.44)of NGC 4493,the host galaxy of BNS merger event GW170817.The new peak is caused by today’s quenched galaxies,which give a large contribution to the total SFR at high redshift in the EMERGE empirical galaxy model.Moreover,we find that the BNS mergers are most likely detected in galaxies with age∼11 Gyr,which is greater than previous results(6−8Gyr)and close to the age of NGC 4993,13.2_(-0.9)^(+0.5)Gyr.

Primordial black holes and third order scalar induced gravitational waves

The process of primordial black hole(PBH)formation is inevitably accompanied by scalar induced gravitational waves(SIGWs).The strong correlation between PBH and SIGW signals may offer a promising approach to detecting PBHs in upcoming gravitational wave experiments,such as the Laser Interferometer Space Antenna(LISA).We investigate third order SIGWs during a radiation-dominated era in the case of the monochromatic primordial power spectrum Pζ=Aζkσ(k-k*).For LISA observations,the relationships between the signal-to-noise ratio(SNR)and monochromatic primordial power spectrum are studied systematically,revealing that the effects of third order SIGWs extend the cutoff frequency from 2f+to 3f and lead to an approximately 200%increase in the SNR for the frequency band from 10^(-5)Hz to 1.6×10^(-3)Hz,corresponding to PBHs with masses in the range 4×10^(-12)M⊙~10^(-7)M⊙.We find that there is a critical value,A×=1.76×10^(-2),for the amplitude of the monochromatic primordial power spectra,such that when Aζ>A*,the energy density of third order SIGWs is larger than that of second order SIGWs.

Multifrequency Gravitational Wave Background from Continuous Sources

Gravitational waves have been detected in the past few years from several transient events such as merging stellar mass black holes, binary neutron stars, etc. These waves have frequencies in a band ranging from a few hundred hertz to around a kilohertz to which LIGO type instruments are sensitive. LISA would be sensitive to much lower range of frequencies from SMBH mergers. Apart from these cataclysmic burst events, there are innumerable sources of radiation which are continuously emitting gravitational waves of all frequencies. These include a whole mass range of compact binary and isolated compact objects as well as close planetary stellar entities. In this work, quantitative estimates are made of the gravitational wave background produced in typical frequency ranges from such sources emitting over a Hubble time and the fluctuations in the h values measured in the usual devices. Also estimates are made of the high frequency thermal background gravitational radiation from hot stellar interiors and newly formed compact objects.

Application of Newtonian approximate model to LIGO gravitational wave data processing

With the observation of a series of ground-based laser interferometer gravitational wave(GW)detectors such as LIGO and Virgo,nearly 100 GW events have been detected successively.At present,all detected GW events are generated by the mergers of compact binary systems and are identified through the data processing of matched filtering.Based on matched filtering,we use the GW waveform of the Newtonian approximate(NA)model constructed by linearized theory to match the events detected by LIGO and injections to determine the coalescence time and utilize the frequency curve for data fitting to estimate the parameters of the chirp masses of binary black holes(BBHs).The average chirp mass of our results is 22.05_(-6.31)^(+6.31)M_(⊙),which is very close to 23.80_(-3.52)^(+4.83)M_(⊙)provided by GWOSC.In the process,we can analyze LIGO GW events and estimate the chirp masses of the BBHs.This work presents the feasibility and accuracy of the low-order approximate model and data fitting in the application of GW data processing.It is beneficial for further data processing and has certain research value for the preliminary application of GW data.

Gravitational waves and primordial black hole productions from gluodynamics by holography

Understanding the nature of quantum chromodynamics(QCD)matter is important but challenging due to the presence of nonperturbative dynamics under extreme conditions.We construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative regime.The equation of state as a function of temperature is in good accordance with the lattice QCD data.Moreover,the Polyakov loop and the gluon condensation,which are proper order parameters to capture the deconfinement phase transition,also agree quantitatively well with the lattice QCD data.We obtain a strong first-order confinement/deconfinement phase transition at Tc=276.5 Me V that is consistent with the lattice QCD prediction.Based on our model for a pure gluon hidden sector,we compute the stochastic gravitational waves and primordial black hole(PBH)productions from this confinement/deconfinement phase transition in the early Universe.The resulting stochastic gravitational-wave backgrounds are found to be within detectability in the International Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the LIGO-Virgo-Collaboration O3 data.

Weak gravitational lensing of quantum perturbed lukewarm black holes and cosmological constant effect

The aim of the paper is to study weak gravitational lensing of quantum(perturbed) and classical lukewarm black holes(QLBHs and CLBHs respectively) in the presence of cosmological parameterΛ.We apply a numerical method to evaluate the deflection angle of bending light rays,image locationsθ of sample source β =-π/4,and corresponding magnifications μ.There are no obtained real values for Einstein ring locations θ_E(β = 0) for CLBHs but we calculate them for QLBHs.As an experimental test of our calculations,we choose mass M of 60 types of the most massive observed galactic black holes acting as a gravitational lens and study quantum matter field effects on the angle of bending light rays in the presence of cosmological constant effects.We calculate locations of non-relativistic images and corresponding magnifications.Numerical diagrams show that the quantum matter effects cause absolute values of the quantum deflection angle to be reduced with respect to the classical ones.The sign of the quantum deflection angle is changed with respect to the classical values in the presence of the cosmological constant.This means dominance of the anti-gravity counterpart of the cosmological horizon on the angle of bending light rays with respect to absorbing effects of 60 local types of the most massive observed black holes.Variations of the image positions and magnifications are negligible when increasing dimensionless cosmological constant ∈=(16ΛM^2)/3.The deflection angle takes positive(negative) values for CLBHs(QLBHs) and they decrease very fast(slowly) by increasing the closest distance x_0 of bending light ray and/or dimensionless cosmological parameter for sample giant black holes with0.001 < ∈ < 0.01.

Primordial black holes and secondary gravitational waves from chaotic infiation

Chaotic inflation is inconsistent with the observational constraint at 68% CL. Here, we show that the enhancement mechanism with a peak function in the noncanonical kinetic term not only helps the chaotic model V(φ) = V0φ^(1/3) satisfy the observational constraint at large scales but also enhances the primordial scalar power spectrum by seven orders of magnitude at small scales.The enhanced curvature perturbations can produce primordial black holes of different masses and secondary gravitational waves with different peak frequencies. We also show that the non-Gaussianities of curvature perturbations have little effect on the abundance of primordial black holes and energy density of the scalar-induced secondary gravitational waves.

On primordial black holes and secondary gravitational waves generated from inflation with solo/multi-bumpy potential

It is well known that a primordial black hole(PBH)can be generated in the inflation process of the early universe,especially when the inflation field has a number of non-trivial features that could break the slow-roll condition.In this study,we investigate a toy model of inflation with bumpy potential,which has one or several bumps.We determined that the potential with multi-bump can generate power spectra with multi-peaks in small-scale region,which can in turn predict the generation of primordial black holes in various mass ranges.We also consider the two possibilities of PBH formation by spherical and elliptical collapses.Finally,we discuss the scalar-induced gravitational waves(SIGWs)generated by linear scalar perturbations at second-order.

Does a Restricted Quintic Polynomial in Minimum Time Step (Planck Time Interval) Being Solvable in a Galois Theory Sense Affect the Closing of a Wormhole Throat if (Kaluza Klein Theory) Is Assumed and Impact Admissible Gravitational Wave Polarization?

In a prior paper, the d = 1 to d = 7 sense of AdS/CFT solutions were described in general whereas we did not introduce commentary as to GW polarization of gravitational radiation from a worm hole. We will discuss GW polarization, for d = 1 and in addition say concrete facts as to the strength of the GW radiation, and admissible frequencies. First off, the term Δt is for the smallest unit of time step. Note that in the small Δt limit for d = 1 we avoid any imaginary time no matter what the sign of Ttemp is. And when d = 1 in order to have any solvability one would need X = Δt assumed to be infinitesimal. To first approximation, we set X = Δt as being of Planck time, 10-31 or so seconds, in duration.

Has LIGO detected primordial black hole dark matter?——tidal disruption in binary black hole formation

The frequent detection of binary mergers of^30 M⊙black holes(BHs)by the Laser Interferometer Gravitational-Wave Observatory(LIGO)rekindled researchers’interest in primordial BHs(PBHs)being dark matter(DM).In this work,we investigated PBHs distributed as DM with a monochromatic mass of 30 M⊙and examined the encounter-capture scenario of binary formation,where the densest central region of DM halo dominates.Thus,we paid special attention to the tidal effect by the supermassive black hole(SMBH)present.In doing so,we discovered a necessary tool called loss zone that complements the usage of loss cone.We found that the tidal effect is not prominent in affecting binary formation,which also turned out to be insufficient in explaining the totality of LIGO’s event rate estimation,especially due to a microlensing event constraining the DM fraction in PBH at the mass of interest from near unity to an order smaller.Meanwhile,an early-universe binary formation scenario proves so prevailing that the LIGO signal in turn constrains the PBH fraction below one percent.Thus,people should put more faith in alternative PBH windows and other DM candidates.

Constraints on individual supermassive binary black holes using observations of PSR J1909-3744

We perform a search for gravitational waves(GWs) from several supermassive binary black hole(SMBBH) candidates(NGC 5548, Mrk 231, OJ 287, PG 1302–102, NGC 4151, Ark 120 and 3C 66B) in long-term timing observations of the pulsar PSR J1909-3744 obtained using the Parkes radio telescope.No statistically significant signals were found. We constrain the chirp masses of those SMBBH candidates and find the chirp mass of NGC 5548 and 3C 66B to be less than 2.4 × 10^9 M⊙ and 2.5 × 10^9 M⊙(with 95% confidence), respectively. Our upper limits remain a factor of 3 to 370 above the likely chirp masses for these candidates as estimated from other approaches. The observations processed here provide upper limits on the GW strain amplitude that improve upon the results from the first Parkes Pulsar Timing Array data release by a factor of 2 to 7. We investigate how information about the orbital parameters can help to improve the search sensitivity for individual SMBBH systems. Finally, we show that these limits are insensitive to uncertainties in the Solar System ephemeris model.

A Gravitational Wave Background from Primordial Black Hole Lattices in Matter Dominated Era

We use the wide-used Einstein Toolkit to solve the Einstein constraints and then simulate the expansion of primordial black hole lattices(PBHLs) with different value of f PBH and m PBH. We find that f PBH plays an important role during the evolution of PBHLs. Since the motion of primordial black holes(PBHs) caused by the expansion of PBHLs occurs at speeds close to that of light, we expect the emission of gravitational waves(GWs) during the expansion of PBHLs. We use both analytical estimates and numerical simulations to cross check the production of GWs in expanding PBHLs.

Did LIGO Really Detect Gravitational Waves?—The Existence of Electromagnetic Interaction Made the Experiments of LIGO Invalid

The paper proves that due to the existence of electromagnetic interaction, the experiments of LIGO cannot detect gravitational waves. This is also the reason why Weber’s experiments of gravitational waves failed. In fact, the formulas of general relativity that gravitational waves affect distances are only suitable for particles in vacuum. LIGO experiments are carried out on the earth. The laser interferometers are fixed on the steel pipes on the earth’s surface in the balanced state of electromagnetic force. Electromagnetic force is 1040 times greater than gravity. Gravitational waves are too weak to overcome electromagnetic force and change the length of steel pipes. Without considering this factor, the design principle of LIGO experiment has serious problem. The experiments to detect gravitational waves should move to space to avoid the influence of electromagnetic interaction. Besides, LIGO experiments have the following problems. 1) No explosion source of gravitational waves is really founded. 2) The argument that the Einstein’s theory of gravity is verified is a vicious circle and invalid in logic. 3) The results of experiments cause sharp contradiction for the energy currents of gravitational waves. The difference reaches to 1024 times and is unacceptable. 4) The method of numerical relativity causes great errors due to the existence of singularities. The errors are enlarged by the effect of butterfly due to the non-linearity of Einstein’s equation of gravity. 5) The so-called change of length 10-18 m between two glasses of interferometers detected in the experiment exceeds the ability of current technique. This kind of precise has entered micro-scalar. The uncertain principle of quantum mechanics makes it impossible. The signs appeared in LIGO experiments are not caused by distance change. 6) LIGO experiments have not detected gravitational waves. What detected may be the signs of disturbances coming from the middle region between two laser interferometers.

Estimating up-limits of eccentricities for the binary black holes in the LIGO-Virgo catalog GWTC-1

In the first Gravitational-Wave Transient Catalogue of LIGO and Virgo,all events are announced having zero eccentricity.In the present paper,we investigate the performance of SEOBNRE,which is a spin-aligned eccentric waveform model in time-domain.By comparing with all the eccentric waveforms in SXS library,we find that the SEOBNRE coincides perfectly with numerical relativity data.Employing the SEOBNRE,we re-estimate the eccentricities of all black hole merger events.We find that most of these events allow a possibility for existence of initial eccentricities at 10 Hz band,but are totally circularized at the observed frequency(≥20 Hz).The upcoming update of LIGO and the next generation detector like Einstein Telescope will observe the gravitational waves starting at 10 Hz or even lower.If the eccentricity exists at the lower frequency,then it may significantly support the dynamical formation mechanism taking place in globular clusters.