arXiv subjects

Yi-Fan Wang

Publications and source records attributed to Yi-Fan Wang.

At least 37 records · Page 2Linked to original sources

arXiv2022

Tests of Gravitational-Wave Birefringence with the Open Gravitational-Wave Catalog

We report the results of testing gravitational-wave birefringence using the largest population of gravitational-wave events currently available. Gravitational-wave birefringence, which can arise from the effective field theory extension of general relativity, occurs when the parity symmetry is broken, causing the left- and right-handed polarizations to propagate following different equations of motion. We perform Bayesian inference on the 94 events reported by the 4th-Open Gravitational-wave Catalog (4-OGC) using a parity-violating waveform. We find no evidence for a violation of general relativity in the vast majority of events. However, the most massive event, GW190521, and the second most massive event, GW191109, show intriguing non-zero results for gravitational-wave birefringence. We find that the probability of association between GW190521 and the possible electromagnetic (EM) counterpart reported by Zwicky Transient Facility (ZTF) is increased when assuming birefringence. Excluding GW190521 and GW191109, the parity-violating energy scale is constrained to $M_\mathrm{PV} > 0.05$ GeV at $90\%$ credible interval, which is an improvement over previous results from twelve events by a factor of five. We discuss the implications of our results on modified gravity and possible alternative explanations such as waveform systematics. More detections of massive binary black hole mergers from the upcoming LIGO/Virgo/KAGRA run will shed light on the true origin of the apparent birefringence.

astro-ph.HE↗

arXiv2022

Search for Coincident Gravitational-wave and Fast Radio Burst Events from 4-OGC and the First CHIME/FRB Catalog

Advanced LIGO and Virgo have reported 90 confident gravitational-wave (GW) observations from compact-binary coalescences from their three observation runs. In addition, numerous subthreshold gravitational-wave candidates have been identified. Binary neutron star (BNS) mergers can produce gravitational waves and short-gamma ray bursts, as confirmed by GW170817/GRB 170817A. There may be electromagnetic counterparts recorded in archival observations associated with subthreshold gravitational-wave candidates. The CHIME/FRB Collaboration has reported the first large sample of fast radio bursts (FRBs), millisecond radio transients detected up to cosmological distances; a fraction of these may be associated with BNS mergers. This work searches for coincident gravitational waves and FRBs from BNS mergers using candidates from the fourth-Open Gravitational-wave Catalog (4-OGC) and the first CHIME/FRB catalog. We use a ranking statistic for GW/FRB association which combines the gravitational-wave detection statistic with the odds of temporal and spatial association. We analyze gravitational-wave candidates and non-repeating FRBs from 2019 April 1 to 2019 July 1, when both the Advanced LIGO/Virgo gravitational-wave detectors and the CHIME radio telescope were observing. The most significant coincident candidate has a false alarm rate of 0.29 per observation time, which is consistent with a null observation. The null results imply, at most, $\mathcal{O}(0.01)\%$ - $\mathcal{O}(1)\%$ of FRBs are produced from the BNS mergers.

astro-ph.HE↗

arXiv2022

Search for Coincident Gravitational Wave and Long Gamma-Ray Bursts from 4-OGC and the Fermi-GBM/Swift-BAT Catalog

The recent discovery of a kilonova associated with an apparent long-duration gamma-ray burst has challenged the typical classification that long gamma-ray bursts originate from the core collapse of massive stars and short gamma-ray bursts are from compact binary coalescence. The kilonova indicates a neutron star merger origin and suggests the viability of gravitational-wave and long gamma-ray burst multimessenger astronomy. Gravitational waves play a crucial role by providing independent information for the source properties. This work revisits the archival 2015-2020 LIGO/Virgo gravitational-wave candidates from the 4-OGC catalog which are consistent with a binary neutron star or neutron star-black hole merger and the long-duration gamma-ray bursts from the Fermi-GBM and Swift-BAT catalogs. We search for spatial and temporal coincidence with up to 10 s time lag between gravitational-wave candidates and the onset of long-duration gamma-ray bursts. The most significant candidate association has only a false alarm rate of once every two years; given the LIGO/Virgo observational period, this is consistent with a null result. We report an exclusion distance for each search candidate for a fiducial gravitational-wave signal and conservative viewing angle assumptions.

astro-ph.HE↗

arXiv2022

4-OGC: Catalog of gravitational waves from compact-binary mergers

We present the fourth Open Gravitational-wave Catalog (4-OGC) of binary neutron star (BNS), binary black hole (BBH) and neutron star-black hole (NSBH) mergers. The catalog includes observations from 2015-2020 covering the first through third observing runs (O1, O2, O3a, O3b) of Advanced LIGO and Advanced Virgo. The updated catalog includes 7 BBH mergers which were not previously reported with high significance during O3b for a total of 94 observations: 90 BBHs, 2 NSBHs, and 2 BNSs. The most confident new detection, GW200318_191337, has component masses $49.1^{+16.4}_{-12.0}\textrm{M}_\odot$ and $31.6^{+12.0}_{-11.6}\textrm{M}_\odot$; its redshift of $0.84^{+0.4}_{-0.35}$ ($90\%$ credible interval) may make it the most distant merger so far. We estimate the merger rate of BBH sources, assuming a powerlaw mass distribution containing an additive Gaussian peak, to be $16.5_{-6.2}^{+10.4} (25.0_{-8.0}^{+12.6})$ Gpc$^{-3}$ yr$^{-1}$ at a redshift of $z=0$ ($0.2$). For BNS and NSBH sources, we estimate a merger rate of $200^{+309}_{-148}$ Gpc$^{-3}$ yr$^{-1}$ and $19^{+30}_{-14}$ Gpc$^{-3}$ yr$^{-1}$, respectively, assuming the known sources are representative of the total population. We provide reference parameter estimates for each of these sources using an up-to-date model accounting for instrumental calibration uncertainty. The corresponding data release also includes our full set of sub-threshold candidates.

astro-ph.HE↗

arXiv2022

Broad search for gravitational waves from subsolar-mass binaries through LIGO and Virgo's third observing run

We present a search for gravitational waves from the coalescence of binaries which contain at least one subsolar mass component using data from the LIGO and Virgo observatories through the completion of their third observing run. The observation of a merger with a component below $1\,M_{\odot}$ would be a clear sign of either new physics or the existence of a primordial black hole population; these black holes could also contribute to the dark matter distribution. Our search targets binaries where the primary has mass $M_1$ between 0.1-100$\,M_{\odot}$ and the secondary has mass $M_2$ from 0.1-1$\,M_{\odot}$ for $M_1 < 20\,M_\odot$ and 0.01-1$\,M_{\odot}$ for $M_1 \ge 20\,M_\odot$. Sources with $M_1 < 7\,M_\odot, M_2 > 0.5\,M_\odot$ are also allowed to have orbital eccentricity up to $e_{10} \sim 0.3$. This search region covers from comparable to extreme mass ratio sources up to $10^4:1$. We find no statistically convincing candidates and so place new upper limits on the rate of mergers; our analysis sets the first limits for most subsolar sources with $7\,M_{\odot}< M_1 < 20\,M_{\odot}$ and tightens limits by $\sim 8\times$ $(1.6\times)$ where $M_1 > 20\,M_{\odot}$ ($M_1 < 7\,M_{\odot}$). Using these limits, we constrain the dark matter fraction to below 0.3 (0.7)$\%$ for 1 (0.5)$\,M_{\odot}$ black holes assuming a monochromatic mass function. Due to the high merger rate of primordial black holes beyond the individual source horizon distance, we also use the lack of an observed stochastic background as a complementary probe to limit the dark matter fraction. We find that although the limits are in general weaker than those from the direct search they become comparable at $0.1 \,M_{\odot}$.

astro-ph.HE↗

arXiv2021

Search for gravitational waves from the coalescence of sub-solar mass binaries in the first half of Advanced LIGO and Virgo's third observing run

We present a search for gravitational waves from the coalescence of sub-solar mass black hole binaries using data from the first half of Advanced LIGO and Virgo's third observing run. The observation of a sub-solar mass black hole merger may be an indication of primordial origin; primordial black holes may contribute to the dark matter distribution. We search for black hole mergers where the primary mass is $0.1-7 M_{\odot}$ and the secondary mass is $0.1-1 M_{\odot}$. A variety of models predict the production and coalescence of binaries containing primordial black holes; some involve dynamical assembly which may allow for residual eccentricity to be observed. For component masses $>0.5 M_{\odot}$, we also search for sources in eccentric orbits, measured at a reference gravitational-wave frequency of 10 Hz, up to $e_{10}\sim 0.3$. We find no convincing candidates and place new upper limits on the rate of primordial black hole mergers. The merger rate of 0.5-0.5 (1.0-1.0)~$M_{\odot}$ sources is $<7100~(1200)$ Gpc$^{-3}$yr$^{-1}$. Our limits are $\sim3-4$ times more constraining than prior analyses. Finally, we demonstrate how our limits can be used to constrain arbitrary models of the primordial black hole mass distribution and merger rate.

astro-ph.HE↗

arXiv2021

3-OGC: Catalog of gravitational waves from compact-binary mergers

We present the third Open Gravitational-wave Catalog (3-OGC) of compact-binary coalescences, based on the analysis of the public LIGO and Virgo data from 2015 through 2019 (O1, O2, O3a). Our updated catalog includes a population of 57 observations, including four binary black hole mergers that had not previously been reported. This consists of 55 binary black hole mergers and the two binary neutron star mergers GW170817 and GW190425. We find no additional significant binary neutron star or neutron star--black hole merger events. The most confident new detection is the binary black hole merger GW190925\_232845 which was observed by the LIGO Hanford and Virgo observatories with $\mathcal{P}_{\textrm{astro}} > 0.99$; its primary and secondary component masses are $20.2^{+3.9}_{-2.5} M_{\odot}$ and $15.6^{+2.1}_{-2.6} M_{\odot}$, respectively. We estimate the parameters of all binary black hole events using an up-to-date waveform model that includes both sub-dominant harmonics and precession effects. To enable deep follow-up as our understanding of the underlying populations evolves, we make available our comprehensive catalog of events, including the sub-threshold population of candidates, and the posterior samples of our source parameter estimates.

astro-ph.HE↗

arXiv2021

Semi-classical predictions of cosmological wave-packets from ridge-lines

We introduce a concept of ridge-lines to investigate the semi-classical prediction from wave-packets with arbitrary width in conventional quantum mechanics and the Wheeler--DeWitt quantum cosmology. Two primary approaches are applied to the exact calculation of the ridge-lines, namely the contour and the stream approach. Moreover, aspects of these are discussed and compared to other scenarios and approaches, i.e. the narrow WKB wave-packets and the first-derivative test. As the main result, we show that the semi-classical predictions in toy models have more abundant solutions than in the classical theory, and most interestingly they may deviate from classical solutions due to the quantum corrections.

gr-qc↗

arXiv2021

Prospects for detecting gravitational waves from eccentric subsolar mass compact binaries

Due to their small mass, subsolar mass black hole binaries would have to be primordial in origin instead of the result of stellar evolution. Soon after formation in the early universe, primordial black holes can form binaries after decoupling from the cosmic expansion. Alternatively, primordial black holes as dark matter could also form binaries in the late universe due to dynamical encounters and gravitational-wave braking. A significant feature for this channel is the possibility that some sources retain nonzero eccentricity in the LIGO/Virgo band. Assuming all dark matter is primordial black holes with a delta function mass distribution, $1M_\odot-1M_\odot$ binaries formed in this late-universe channel can be detected by Advanced LIGO and Virgo with their design sensitivities at a rate of $\mathcal{O}(1)$/year, where $12\%(3\%)$ of events have eccentricity at a gravitational-wave frequency of 10 Hz, $e^\mathrm{10Hz}\geq0.01(0.1)$, and nondetection can constrain the binary formation rate within this model. Third generation detectors would be expected to detect subsolar mass eccentric binaries as light as $0.01 M_\odot$ within this channel, if they accounted for the majority of the dark matter. Furthermore, we use simulated gravitational-wave data to study the ability to search for eccentric gravitational-wave signals using a quasi-circular waveform template bank with Advanced LIGO design sensitivity. For a match-filtering targeted search, assuming binaries with a delta function mass of $0.1(1)M_\odot$ and the eccentricity distribution derived from this late-universe formation channel, $41\%(6\%)$ of the signals would be missed compared to the ideal detection rate due to the mismatch in the gravitational-wave signal from eccentricity.

astro-ph.HE↗

arXiv2021

Gravitational-Wave Implications for the Parity Symmetry of Gravity at GeV Scale

Einstein's general relativity, as the most successful theory of gravity, is one of the cornerstones of modern physics. However, the experimental tests for gravity in the high energy region are limited. The emerging gravitational-wave astronomy has opened an avenue for probing the fundamental properties of gravity in strong and dynamical field, and in particular, high energy regime. In this work, we test the parity conservation of gravity with gravitational waves. If the parity symmetry is broken, the left- and right-handed modes of gravitational waves would follow different equations of motion, dubbed as birefringence. We perform full Bayesian inference by comparing the state-of-the-art waveform with parity violation with the compact binary coalescence data released by LIGO and Virgo collaboration. We do not find any violations of general relativity, thus constrain the lower bound of the parity-violating energy scale to be $0.09$ GeV through the velocity birefringence of gravitational waves. This provides the most stringent experimental test of gravitational parity symmetry up to date. We also find third generation gravitational-wave detectors can enhance this bound to $\mathcal{O}(10^2)$ GeV if there is still no violation, comparable to the current LHC energy scale in particle physics, which indicates gravitational-wave astronomy can usher in a new era of testing the ultraviolet behavior of gravity in the high energy region.

gr-qc↗

arXiv2021

Search for gravitational waves from the coalescence of sub-solar mass and eccentric compact binaries

We present the first search for gravitational waves from sub-solar mass compact-binary mergers which allows for non-negligible orbital eccentricity. Sub-solar mass black holes are a signature of primordial origin black holes, which may be a component of dark matter. To produce binary coalescences, primordial black holes may form close binaries either in the early universe or more recently through dynamical interactions. A signature of dynamical formation would be the observation of non-circularized orbits. We search for black hole mergers where the primary mass is $0.1-7 M_{\odot}$ and the secondary mass is $0.1-1 M_{\odot}$. We allow for eccentricity up to $\sim0.3$ at a dominant-mode gravitational-wave frequency of 10 Hz for binaries with at least one component with mass $>0.5 M_{\odot}$. We find no convincing candidates in the public LIGO data. The two most promising candidates have a false alarm rate of 1 per 3 and 4 years, respectively, which combined is only a $\sim 2.4σ$ deviation from the expected Poisson rate. Given the marginal statistical significance, we place upper limits on the rate of sub-solar mass mergers under the assumption of a null observation and compare how these limits may inform the possible dark matter contribution.

astro-ph.HE↗

arXiv2020

Search for gravitational waves from high-mass-ratio compact-binary mergers of stellar mass and sub-solar mass black holes

We present the first search for gravitational waves from the coalescence of stellar mass and sub-solar mass black holes with masses between $20 - 100~\mathrm{M}_{\odot}$ and $0.01 - 1~\mathrm{M}_{\odot}~($10 - 10^3$~\mathrm{M}_{J})$, respectively. The observation of a single sub-solar mass black hole would establish the existence of primordial black holes and a possible component of dark matter. We search the $\sim 164$ days of public LIGO data from 2015-2017 when LIGO-Hanford and LIGO-Livingston were simultaneously observing. We find no significant candidate gravitational-wave signals. Using this non-detection, we place a $90\%$ upper limit on the rate of $30-0.01~\mathrm{M}_{\odot}$ and $30-0.1~\mathrm{M}_{\odot}$ mergers at $<1.2\times10^{6}$ and $<1.6\times10^{4} ~\mathrm{Gpc}^{-3} \mathrm{yr}^{-1}$, respectively. If we consider binary formation through direct gravitational-wave braking, this kind of merger would be exceedingly rare if only the lighter black hole were primordial in origin ($<10^{-4}~\mathrm{Gpc}^{-3}\mathrm{yr}^{-1}$). If both black holes are primordial in origin, we constrain the contribution of $1 (0.1)~\mathrm{M}_{\odot}$ black holes to dark matter to $< 0.3 (3)\%$.

astro-ph.HE↗

arXiv2020

The TianQin project: current progress on science and technology

TianQin is a planned space-based gravitational wave (GW) observatory consisting of three earth orbiting satellites with an orbital radius of about $10^5~{\rm km}$. The satellites will form a equilateral triangle constellation the plane of which is nearly perpendicular to the ecliptic plane. TianQin aims to detect GWs between $10^{-4}~{\rm Hz}$ and $1~{\rm Hz}$ that can be generated by a wide variety of important astrophysical and cosmological sources, including the inspiral of Galactic ultra-compact binaries, the inspiral of stellar-mass black hole binaries, extreme mass ratio inspirals, the merger of massive black hole binaries, and possibly the energetic processes in the very early universe or exotic sources such as cosmic strings. In order to start science operations around 2035, a roadmap called the 0123 plan is being used to bring the key technologies of TianQin to maturity, supported by the construction of a series of research facilities on the ground. Two major projects of the 0123 plan are being carried out. In this process, the team has created a new generation $17~{\rm cm}$ single-body hollow corner-cube retro-reflector which has been launched with the QueQiao satellite on 21 May 2018; a new laser ranging station equipped with a $1.2~{\rm m}$ telescope has been constructed and the station has successfully ranged to all the five retro-reflectors on the Moon; and the TianQin-1 experimental satellite has been launched on 20 December 2019 and the first round result shows that the satellite has exceeded all of its mission requirements.

gr-qc↗

arXiv2020

Searching for primordial black holes with stochastic gravitational-wave background in the space-based detector frequency band

Assuming that primordial black holes compose a fraction of dark matter, some of them may accumulate at the center of galaxy and perform a prograde or retrograde orbit against the gravity pointing towards the center exerted by the central massive black hole. If the mass of primordial black holes is of the order of stellar mass or smaller, such extreme mass ratio inspirals can emit gravitational waves and form a background due to incoherent superposition of all the contributions of the Universe. We investigate the stochastic gravitational-wave background energy density spectra from the directional source, the primordial black holes surrounding Sagittarius A$^\ast$ of the Milky Way, and the isotropic extragalactic total contribution, respectively. As will be shown, the resultant stochastic gravitational-wave background energy density shows different spectrum features such as the peak positions in the frequency domain for the above two kinds of sources. Detection of stochastic gravitational-wave background with such a feature may provide evidence for the existence of primordial black holes. Conversely, a null searching result can put constraints on the abundance of primordial black holes in dark matter.

astro-ph.CO↗

arXiv2019

Dynamically Assisted Schwinger Effect at Strong Coupling with Its Holographic Extension

At strong-coupling and weak-field limit, the scalar Schwinger effect is studied by the field-theoretical method of worldline instantons for dynamic fields of single-pulse and sinusoidal types. By examining the Wilson loop along the closed instanton path, corrections to the results obtained from weak-coupling approximations are discovered. They show that this part of contribution for production rate becomes dominant as Keldysh parameter increases, it makes the consideration at strong coupling turn out to be indispensable for dynamic fields. Moreover a breaking of weak-field condition similar to constant field also happens around the critical field, defined as a point of vacuum cascade. In order to make certain whether the vacuum cascade occurs beyond the weak-field condition, following Semenoff and Zarembo's proposal, the Schwinger effects of dynamic fields are studied with an $\mathcal{N}=4$ supersymmetric Yang--Mills theory in the Coulomb phase. With the help of the gauge/gravity duality, the vacuum decay rate is evaluated by the string action with instanton worldline as boundary, which is located on a probe D3-brane. The corresponding classical worldsheets are estimated by perturbing the integrable case of a constant field.

hep-th↗

arXiv2019

Science with the TianQin observatory: Preliminary results on massive black hole binaries

We investigate the prospects of detecting gravitational waves from coalescing massive black hole binaries in the Universe with the TianQin observatory, a space-based gravitational wave interferometer proposed to be launched in the 2030s. To frame the scientific scope of the mission, in this paper, we carry out a preliminary estimation of the signal-to-noise ratio, detection rate and parameter estimation precision of massive black hole binaries detectable by TianQin. In order to make our results as robust as possible, we consider several models of the growth history of massive black holes, exploring the effect of some key astrophysical prescriptions as well the impact of the employed computational methods. In the most optimistic model, TianQin can detect as many as approximately 60 mergers per year. If TianQin detects a merger at redshift of 15, it will be capable of estimating its luminosity distance to within an accuracy of 10%; for a nearby event at redshift approximately 2, TianQin can issue early warnings 24 hours before coalescence, with a timing accuracy of around three hours and a sky localization ability of approximately 80 deg$^2$, thus enabling multi-messenger observations.

astro-ph.HE↗

arXiv2018

Finding the proper node ranking method for complex networks

Ranking node importance is crucial in understanding network structure and function on complex networks. Degree, h-index and coreness are widely used, but which one is more proper to a network associated with a dynamical process, e.g. SIR spreading process, is still unclear. To fill this gap, a, which is extracted from the fitting function (f(x)=1-1/(e^(2a(x-b))+1)) of the average number of nodes in each radius of the neighborhood of a node, is proposed. Experiment results which are carried out on twenty real-world networks show that a can classify which of the three measures (degree, h-index and coreness) is more proper to a network in ranking node importance. We also find that [b/3] is a good indicator for forecasting the optimal radius of the neighborhood of a node in ranking node importance for a given network. To the best of our knowledge, it is the first solution of this interesting and open issue. Furthermore, by extending the range of neighborhood where we construct an operator H on of a node, we propose a new method to quantify the importance of a node. The ranking accuracies of most networks can be improved when the radius is increased from 0 to its forecasting optimal radius and the improvement, for the best case, reaches up to 111%. The performances will reduce on half of the networks studied in this paper if we roughly extend the radius of the neighborhood. Our work deepens the understanding of how to find out the proper node ranking method for complex networks. The proposed methods bridge the gaps among network structure and node importance, and may have potential applications in controlling the outbreak of disease, designing of optimal information spreading strategies.

physics.soc-ph↗

arXiv2018

Integrable Minisuperspace Models with Liouville Field: Energy Density Self-Adjointness and Semiclassical Wave Packets

The homogeneous cosmological models with a Liouville scalar field are investigated in classical and quantum context of Wheeler-DeWitt geometrodynamics. In the quantum case of quintessence field with potential unbounded from below and phantom field, the energy density operators are not essentially self-adjoint and self-adjoint extensions contain ambiguities. Therefore the same classical actions correspond to a family of distinct quantum models. For the phantom field the energy spectrum happens to be discrete. The probability conservation and appropriate classical limit can be achieved with a certain restriction of the functional class. The appropriately localized wave packets are studied numerically using the Schrodinger's norm and a conserved Mostafazadeh's norm introduced from techniques of pseudo-Hermitian quantum mechanics. These norms give a similar packet evolution that is confronted with analytical classical solutions.

hep-th↗