LISA Symposium XIV Parallel A Beyond LISA Part 2 @LISAcommunity

Uploaded August 2022 | Updated September 2026, 13 minutes ago

LISA Symposium XIV Parallel A Beyond LISA Part 2

$Numerical Relativity Surrogate model for eccentric binary black hole gravitational waveform Numerical Relativity Surrogate model for eccentric binary black hole gravitational waveform Tousif Islam, Vijay Varma, Jacqueline Lodman, Scott Field and Gaurav Khanna Though Numerical Relativity (NR) simulations provide the most accurate gravitational waveforms for binary black holes (BBHs), they are computationally expensive, taking days to weeks to generate one single waveform. NR surrogate waveform models are computationally cheaper without sacrificing accuracy. While surrogate models for non-spinning, aligned spin and precessing BBHs are quite reliable, efforts to build an eccentric NR surrogate model are still at an early stage. We provide detailed data decomposition and parameterization strategies to build an effective NR surrogate for eccentric BBHs waveforms. Based on the proposed framework, we then present a time domain, inspiral-merger-ringdown NR surrogate model for eccentric binary black holes for mass ratio $q=1$. We call it NRSur2dq1Ecc. The model includes the (l=2,m=2), (l=3,m=2) and (l=4,m=4) spin-weighted spherical harmonic modes. The odd $m$ modes are zero due to the symmetry of the system. We parameterize the effect of eccentricity via eccentric parameter $e_w$ and mean anomaly $l_w$. This model has been trained against 41 NR waveforms with mass ratio $q=1$, $e_wlt0.175$ and $0ltl_wlt2pi$ (as estimated at a reference time of $t_{ref} 4200M$); and uses Gaussian Process Regression to build the fits across parameter space. We show that our model can accurately predict NR waveforms with mismatches $approx 10^{-3}$ and can recover subtle effects like mode-mixing in the ringdown signal. The method proposed here would pave the way forward for constructing any future surrogate waveform model with eccentric binaries.$

IfoCAD simulations for TTL noise analyses in LISA

LISA Symposium XIV Parallel A LISA Instrumentation 3 Part 2

Experimental backscatter measurement rig for LISA beam dumps and FIOS characterisation

About the modes and tones of Black Hole Ringdowns

LISA Symposium XIV Day 1 Plenary Block 1 Complete

Predictions for Ultra Compact X-Ray Binaries from Combined GW and Electromagnetic Wave Observations

$Testing of a First-Generation Optical Truss Interferometer for the LISA Telescope The LISA telescope is a bidirectional component that is used to expand an outgoing laser beam to the far spacecraft as well as compress a small fraction of a large incoming beam to a diameter of a few mm at the optical bench. Since the telescope lies directly in the path of the long-baseline LISA interferometer, its structure must be dimensionally stable at the pm/âˆšHz level within the 0.1 mHz â€“ 1 Hz frequency band. A way to measure the displacement noise along the optical path of the telescope is with a compact optical truss interferometer (OTI), consisting of three Fabry-Perot cavities mounted along the telescope to monitor structural distortions over time. The premise is that variations in the cavity lengths will be due to dimensional changes in the telescope structure along three different lateral positions. We have developed a fiber-coupled Pound-Drever-Hall (PDH) system that integrates a fiber injector, mode matching optics, and a cavity input mirror into a compact input stage. These input stages will be attached around the primary mirror of the telescope, while the cavity return mirrors will be attached around the secondary mirror of the telescope. Using a PDH-like frequency locking scheme, variations in the cavity lengths will shift the frequency of the locked 1064 nm light which can be monitored through a beat signal between the light from each cavity and a separate laser that is locked to an ultra-stable reference cavity. We have designed and procured three first-generation OTI cavities and are currently testing the prototypes to verify pm/âˆšHz displacement sensitivity. We will present details regarding the design, fabrication, and assembly of the OTI units as well as preliminary results on the prototype testing and plans for future testing and verification. Authors: Kylan Jersey, Ian Harley-Trochimczyk, Yanqi Zhang, Felipe Guzman Presenter: Kylan Jersey$

RF differential phase measurements of the LISA fiber amplifier