DSpace Community:https://hdl.handle.net/2440/495572023-04-01T11:14:15Z2023-04-01T11:14:15ZModel-based Cross-correlation Search for Gravitational Waves from the Low-mass X-Ray Binary Scorpius X-1 in LIGO O3 DataAbbott, R.Abe, H.Acernese, F.Ackley, K.Adhicary, S.Adhikari, N.Adhikari, R.X.Adkins, V.K.Adya, V.B.Affeldt, C.Agarwal, D.Agathos, M.Aguiar, O.D.Aiello, L.Ain, A.Ajith, P.Akutsu, T.Albanesi, S.Alfaidi, R.A.Alléné, C.et al.https://hdl.handle.net/2440/1377432023-03-29T02:11:50Z2022-01-01T00:00:00ZTitle: Model-based Cross-correlation Search for Gravitational Waves from the Low-mass X-Ray Binary Scorpius X-1 in LIGO O3 Data
Author: Abbott, R.; Abe, H.; Acernese, F.; Ackley, K.; Adhicary, S.; Adhikari, N.; Adhikari, R.X.; Adkins, V.K.; Adya, V.B.; Affeldt, C.; Agarwal, D.; Agathos, M.; Aguiar, O.D.; Aiello, L.; Ain, A.; Ajith, P.; Akutsu, T.; Albanesi, S.; Alfaidi, R.A.; Alléné, C.; et al.
Abstract: We present the results of a model-based search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1 using LIGO detector data from the third observing run of Advanced LIGO and Advanced Virgo. This is a semicoherent search that uses details of the signal model to coherently combine data separated by less than a specified coherence time, which can be adjusted to balance sensitivity with computing cost. The search covered a range of gravitational-wave frequencies from 25 to 1600 Hz, as well as ranges in orbital speed, frequency, and phase determined from observational constraints. No significant detection candidates were found, and upper limits were set as a function of frequency. The most stringent limits, between 100 and 200 Hz, correspond to an amplitude h0 of about 10⁻²⁵ when marginalized isotropically over the unknown inclination angle of the neutron star’s rotation axis, or less than 4 × 10⁻²⁶ assuming the optimal orientation. The sensitivity of this search is now probing amplitudes predicted by models of torque balance equilibrium. For the usual conservative model assuming accretion at the surface of the neutron star, our isotropically marginalized upper limits are close to the predicted amplitude from about 70 to 100 Hz; the limits assuming that the neutron star spin is aligned with the most likely orbital angular momentum are below the conservative torque balance predictions from 40 to 200 Hz. Assuming a broader range of accretion models, our direct limits on gravitational-wave amplitude delve into the relevant parameter space over a wide range of frequencies, to 500 Hz or more.
Description: Published 2022 December 162022-01-01T00:00:00ZAll-sky search for continuous gravitational waves from isolated neutron stars using Advanced LIGO and Advanced Virgo O3 dataAbbott, R.Abe, H.Acernese, F.Ackley, K.Adhikari, N.Adhikari, R.X.Adkins, V.K.Adya, V.B.Affeldt, C.Agarwal, D.Agathos, M.Agatsuma, K.Aggarwal, N.Aguiar, O.D.Aiello, L.Ain, A.Ajith, P.Akutsu, T.Albanesi, S.Alfaidi, R.A.et al.https://hdl.handle.net/2440/1377422023-03-29T02:07:25Z2022-01-01T00:00:00ZTitle: All-sky search for continuous gravitational waves from isolated neutron stars using Advanced LIGO and Advanced Virgo O3 data
Author: Abbott, R.; Abe, H.; Acernese, F.; Ackley, K.; Adhikari, N.; Adhikari, R.X.; Adkins, V.K.; Adya, V.B.; Affeldt, C.; Agarwal, D.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O.D.; Aiello, L.; Ain, A.; Ajith, P.; Akutsu, T.; Albanesi, S.; Alfaidi, R.A.; et al.
Abstract: We present results of an all-sky search for continuous gravitational waves which can be produced by spinning neutron stars with an asymmetry around their rotation axis, using data from the third observing run of the Advanced LIGO and Advanced Virgo detectors. Four different analysis methods are used to search in a gravitational-wave frequency band from 10 to 2048 Hz and a first frequency derivative from −10⁻⁸ to 10⁻⁹ Hz/s. No statistically significant periodic gravitational-wave signal is observed by any of the four searches. As a result, upper limits on the gravitational-wave strain amplitude h₀ are calculated. The best upper limits are obtained in the frequency range of 100 to 200 Hz and they are ∼1.1 × 10⁻²⁵ at 95% confidence level. The minimum upper limit of 1.10 × 10⁻²⁵ is achieved at a frequency 111.5 Hz. We also place constraints on the rates and abundances of nearby planetary- and asteroid-mass primordial black holes that could give rise to continuous gravitational-wave signals.
Description: Published 28 November 20222022-01-01T00:00:00ZLithium niobate photonics: Unlocking the electromagnetic spectrumBoes, A.Chang, L.Langrock, C.Yu, M.Zhang, M.Lin, Q.Lončar, M.Fejer, M.Bowers, J.Mitchell, A.https://hdl.handle.net/2440/1376782023-03-22T01:27:02Z2023-01-01T00:00:00ZTitle: Lithium niobate photonics: Unlocking the electromagnetic spectrum
Author: Boes, A.; Chang, L.; Langrock, C.; Yu, M.; Zhang, M.; Lin, Q.; Lončar, M.; Fejer, M.; Bowers, J.; Mitchell, A.
Abstract: Lithium niobate (LN), first synthesized 70 years ago, has been widely used in diverse applications ranging from communications to quantum optics. These high-volume commercial applications have provided the economic means to establish a mature manufacturing and processing industry for high-quality LN crystals and wafers. Breakthrough science demonstrations to commercial products have been achieved owing to the ability of LN to generate and manipulate electromagnetic waves across a broad spectrum, from microwave to ultraviolet frequencies. Here, we provide a high-level Review of the history of LN as an optical material, its different photonic platforms, engineering concepts, spectral coverage, and essential applications before providing an outlook for the future of LN.2023-01-01T00:00:00ZRidge waveguide couplers with leaky mode resonator-like wavelength responsesSchoenhardt, S.Boes, A.Nguyen, T.G.Mitchell, A.https://hdl.handle.net/2440/1376112023-03-27T03:14:33Z2023-01-01T00:00:00ZTitle: Ridge waveguide couplers with leaky mode resonator-like wavelength responses
Author: Schoenhardt, S.; Boes, A.; Nguyen, T.G.; Mitchell, A.
Abstract: Integrated photonic resonators based on bound states in the continuum (BICs) on the silicon-on-insulator (SOI) platform have the potential for novel, mass-manufacturable resonant devices. While the nature of BIC-based ridge resonators requires the resonators to be extended in the (axial) propagation direction of the resonant mode, the requirement for excitation from the quasi-continuum extends the resonator structures also in the lateral dimensions, resulting in large device footprints. To overcome this footprint requirement, we investigate the translation of BIC-based ridge resonators into a guided mode system with finite lateral dimensions. We draw analogies between the resulting waveguide system and the BIC-based resonators and numerically demonstrate that, analog to the BIC-based resonators, such a waveguide system can exhibit spectrally narrow-band inversion of its transmissive behavior.2023-01-01T00:00:00Z