All-sky search for long-duration gravitational wave transients with initial LIGO

We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

All-sky search for long-duration gravitational wave transients with initial LIGO

We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

[no abstract available

Some energy levels in P(30) observed in radiative capture by Si(29) of protons with energies from 1420 to 2160 keV

The excitation function for the Si~(p,p)P" reaction has been experimentally determined in the proton energy range from 1420 through 2160 keV. Unreported resonances in this reaction have been identified at 1975, 2033, 2075, and 2117 keV with estimated errors of ~4 keV, corresponding to energy levels in P~ at 7.49, 7.55, 7.59, and 7.63 MeV. Gamma spectra at these resonances are obscured by contaminant radiation but suggest complex decay schemes. Double angular-correlation measurements have been made at the 1470-keV resonance indicating a resonance-level spin of 2+, or less probably, 2—.The level at 4.50 MeV in P30 is shown to probably have a spin of 2+ or, less probably, 3+; these spin values are in disagreement with the 0+ that has been predicted for this level.U.S. Office of Naval ResearchApproved for public release; distribution is unlimited

A reminder before extinction strengthens episodic memory via reconsolidation but fails to disrupt generalized threat responses

Contains fulltext : 177015.pdf (publisher's version ) (Open Access)A reminder can temporarily renew flexibility of consolidated memories, referred to as reconsolidation. Pavlovian threat-conditioning studies suggest that a reminder can renew flexibility of threat responses but that episodic memories remain stable. In contrast, outside the threat-conditioning domain, studies testing memory for word lists or stories find that a reminder can renew flexibility of episodic memory. This discrepancy in findings leaves it unclear if episodic memories reconsolidate, or only Pavlovian responses. Here we unite the different approaches in the field and show that a reminder can retroactively strengthen episodic memory for Pavlovian threat-conditioned events, but that, in contrast to threat-conditioning studies with simple sensory stimuli, extinction after a reminder fails to prevent recovery of generalized threat responses. Our results indicate the episodic memories also reconsolidate, allowing strengthening of relevant memories. These findings also suggest that generalized threat responses and episodic memories are less susceptible to be modified by reminder-interventions procedures

A cognitively demanding working-memory intervention enhances extinction

Contains fulltext : 227031.pdf (publisher's version ) (Open Access)Improving extinction learning has the potential to optimize psychotherapy for persistent anxiety-related disorders. Recent findings show that extinction learning can be improved with a cognitively demanding eye-movement intervention. It is, however, unclear whether [1] any cognitively-demanding task can enhance extinction, or whether it is limited to eye movements, and [2] the effectiveness of such an intervention can be enhanced by increasing cognitive load. Participants (n = 102, n = 75 included in the final sample) completed a Pavlovian threat conditioning paradigm across two days. One group underwent standard extinction (Control), a second group underwent extinction paired with a 1-back working memory task (Low-Load), and a third group underwent extinction paired with a 2-back working memory task (High-Load). We found that the conditioned response during extinction was reduced for both the Low-Load and the High-Load groups compared to the Control group. This reduction persisted during recovery the following day when no working memory task was executed. Finally, we found that within the High-Load group, participants with lower accuracy scores on the 2-back task (i.e., for who the task was more difficult) had a stronger reduction in the conditioned response. We did not observe this relationship within the Low-Load group. Our findings suggest that cognitive load induced by a working memory intervention embedded during extinction reduces persistent threat responses.11 p