A morphology-independent search for gravitational wave echoes in data from the first and second observing runs of Advanced LIGO and Advanced Virgo

Abstract

Gravitational wave echoes have been proposed as a smoking-gun signature of exotic compact objects with near-horizon structure. Recently there have been observational claims that echoes are indeed present in stretches of data from Advanced LIGO and Advanced Virgo immediately following gravitational wave signals from presumed binary black hole mergers, as well as a binary neutron star merger. In this paper we deploy a morphology-independent search algorithm for echoes introduced in Tsang et al., Phys. Rev. D 98, 024023 (2018), which (a) is able to accurately reconstruct a possible echoes signal with minimal assumptions about their morphology, and (b) computes Bayesian evidences for the hypotheses that the data contain a signal, an instrumental glitch, or just stationary, Gaussian noise. Here we apply this analysis method to all the significant events in the first Gravitational Wave Transient Catalog (GWTC-1), which comprises the signals from binary black hole and binary neutron star coalescences found during the first and second observing runs of Advanced LIGO and Advanced Virgo. In all cases, the ratios of evidences for signal versus noise and signal versus glitch do not rise above their respective "background distributions" obtained from detector noise, the smallest p-value being 3% (for event GW170823). Hence we find no statistically significant evidence for echoes in GWTC-1.

Quantum Black Holes in the Sky

“…Table 18. Log Bayes factors for signal versus noise and signal versus glitch, and the corresponding p-values, for events seen in two detectors of GWTC-1 [10]. The bottom row shows the combined p-values for all these events together.…”

“…Plugging Eqs. (9)(10)(11)(12)(13) into the the Israel junction condition, we find in the zeroth order in :…”

“…Out of these, 8 studies find some observational evidence for echoes [1][2][3][4][5][6][7][8], 3 are comment notes [26][27][28], and 3 more [2,9,10] found no significant echo signals in the binary BH merger events. We can sort them into eight independent groups with 1. positive [2][3][4][5]141], 2. mixed [6][7][8], and 3. negative [2,9,10] results.…”

“…In order to have an optimal search for echoes, one may want to take the following guidelines into consideration: 66 Table 19. Same as Table 18, while for the events that three detectors has been involved [10]. In the case of GW170817, in order to cover 1.0 sec after the merger for echoes found by Abedi and Afshordi [3], additional search as first echo being from this time has been set.…”

Analytical model for gravitational-wave echoes from spinning remnants

“…Tentative evidence for echoes in the combined LIGO/Virgo binary BH events [13,14] and in the neutron-star binary coalescence GW170817 [15] have been reported, followed by controversial claims about the statistical significance of such results [13,14,[16][17][18][19], and by recent negative searches using a more accurate template [20] and a morphology-independent algorithm [21]. Performing a reliable search for echoes requires developing data analysis techniques as well as constructing accurate waveform models.…”