Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

The Development of Reporting Norms without Explicit Guidance: An Example from Accounting for Gift Cards

This study examines the evolution of retail firms\u27 financial reporting for unused gift cards (i.e., breakage) as an example of how reporting norms develop in the absence of explicit authoritative guidance. We find that firms exhibit a wide range of accounting and reporting choices but show significant increases in the quantity and detail of disclosure over time. Consistent with our predictions, these changes in disclosure are positively related to initial disclosure levels below the average of industry peers, the receipt of a related SEC comment letter, and specific external auditors (especially those with a high frequency of related comment letters in their client portfolio). Overall, the evolution of reporting norms for gift card breakage demonstrates the role the SEC, peers, and auditors have in quickly shaping U.S. reporting norms in the absence of formal disclosure requirements

The Importance of Distinguishing Errors from Irregularities in Restatement Research: The Case of Restatements and CEO/CFO Turnover

Research on restatements has grown significantly in recent years. Many of these studies test hypotheses about the causes and consequences of intentional managerial misreporting but rely on restatement data (such as the GAO database) that contains both irregularities (intentional misstatements) and errors (unintentional misstatements). We argue that researchers can significantly enhance the power of tests related to restatements by distinguishing between errors and irregularities, particularly in recent periods when the relative frequency of error-related restatements is increasing. Based on prior research, the reading of numerous restatement announcements, and the guidance that boards receive from lawyers, auditors, and the SEC on how to respond to suspicions of deliberate misreporting, we propose a straightforward procedure for classifying restatements as either errors or irregularities. We show that most of the restatements we classify as irregularities are followed by fraud-related class action lawsuits as compared to only one lawsuit in the group of restatements classified as errors. As further validation of our proxy, we report that the market reaction to the restatement announcement for our irregularities sample (−14 percent) is also significantly more negative than it is for our errors sample (−2 percent). Finally, we demonstrate the importance of distinguishing errors from irregularities by showing the impact it has on inferences about the relation between restatements and CEO/CFO turnover over time

Determinants and Market Consequences of Auditor Dismissals after Accounting Restatements

ABSTRACT This study examines the conditions under which financial restatements lead corporate boards to dismiss external auditors and how the market responds to those dismissal announcements. We find that auditors are more likely to be dismissed after more severe restatements but that the severity effect is primarily attributable to the dismissal of non-Big 4 auditors rather than Big 4 auditors. We also document that among corporations with Big 4 auditors, those that are larger and more complex operationally are less likely to dismiss their auditors. Combined, this evidence suggests that firms with higher switching costs and fewer replacement auditor choices are less likely to dismiss their auditors after a restatement, which is informative to the debates about the costs and benefits of mandatory auditor rotation and limited competition in the audit market. Additionally, we examine contemporaneous executive turnover and find evidence that boards view auditor dismissals as complementary rather than substitute responses to restatements. Finally, we investigate the market reaction to auditor dismissals after restatements. The market reaction to the dismissal is significantly more positive following more severe restatements (5.9 percent) relative to less severe restatements (0.6 percent) when the client engages a comparably sized auditor. This positive market reaction is consistent with firms restoring financial reporting credibility by replacing their auditors and highlights the important role that auditors play in the financial markets. Data Availability: Data are available from public sources indicated in the text