SearcharxivSearch

arXiv subjects

Marco Meyer-Conde

Publications and source records attributed to Marco Meyer-Conde.

7 recordsLinked to original sources

Wavelet-Based Extraction of Transient Noise in Gravitational-Wave Interferometers using a Saliency-Guided Learning Architecture

Gravitational-wave interferometers exhibit a wide variety of short-duration non-Gaussian transients, commonly referred to as glitches, that complicate the detection of astrophysical signals, bias parameter estimation, and detector characterisation. Existing machine-learning approaches classify glitch morphologies but do not provide a complete mechanism to segment and extract these disturbances from the strain data. We introduce a wavelet-based, saliency-guided framework for the supervised extraction of transient noise. Candidates are first pre-tagged using Uniform Manifold Approximation and Projection, which is also used as a diagnostic of the learned representations. A traditional learning model operating on Continuous Wavelet Transform spectrograms then identifies relevant time-frequency regions through saliency maps. These saliency patterns are transferred to an invertible multiresolution representation via the Discrete Wavelet Transform, where adaptive coefficient masking enables exact reconstruction of both glitch-only and glitch-suppressed waveforms. We demonstrate effective extraction across several representative glitch families, including 'Whistle' and 'Scattered-Light' transients, and show robustness in challenging regimes such as low signal-to-noise events and partially overlapping structures, where classical thresholding or band-limited filtering methods typically fail or introduce leakage. The proposed framework offers an interpretable and computationally efficient approach to transient-noise extraction, establishing a foundation for scalable applications to larger glitch catalogs and future observing runs.

astro-ph.IM

Glitch noise classification in KAGRA O3GK observing data using unsupervised machine learning

Gravitational wave interferometers are disrupted by various types of nonstationary noise, referred to as glitch noise, that affect data analysis and interferometer sensitivity. The accurate identification and classification of glitch noise are essential for improving the reliability of gravitational wave observations. In this study, we demonstrated the effectiveness of unsupervised machine learning for classifying images with nonstationary noise in the KAGRA O3GK data. Using a variational autoencoder (VAE) combined with spectral clustering, we identified eight distinct glitch noise categories. The latent variables obtained from VAE were dimensionally compressed, visualized in three-dimensional space, and classified using spectral clustering to better understand the glitch noise characteristics of KAGRA during the O3GK period. Our results highlight the potential of unsupervised learning for efficient glitch noise classification, which may in turn potentially facilitate interferometer upgrades and the development of future third-generation gravitational wave observatories.

gr-qc

Regression of Suspension Violin Modes in KAGRA O3GK Data with Kalman Filters

Suspension thermal modes in interferometric gravitational-wave detectors produce narrow, high-Q spectral lines that can contaminate gravitational searches and bias parameter estimation. In KAGRA, cryogenic mirrors are held by thick suspension fibers, designed to sustain such a low-temperature environment, which may further affect inharmonicity modes, fiber dimensions, and mechanical behavior compared to typical interferometers. As these modes remain a prominent source of narrowband contamination, we implement a Kalman filter to model and track violin lines, building on the methodology introduced in [1], and apply subtraction to KAGRA O3GK data. Using gravitational-wave template injections, we validate that the subtraction preserves matched-filter SNR while effectively suppressing line power. Comparisons of power spectral densities and residual analyses confirm that the method removes deterministic line contributions without introducing waveform distortions. This approach provides a cleaner strain channel for searches and parameter estimation and will become increasingly important for future low-temperature detectors with higher-Q suspensions, such as the Einstein Telescope.

gr-qc

Gravitational Wave Memory from Accelerating Relativistic Jets in Multiple Thick Shell Scenarios

Gravitational wave (GW) memory, a permanent distortion of the space-time metric, is anticipated during the acceleration of relativistic jets in gamma-ray bursts (GRBs). While the precise mechanism behind GRBs is not yet fully understood, detecting GW memory may contribute to clarifying their nature. In this paper, we consider various scenarios of GW memory emission, including both single and multiple shells with thin- and thick-shells. In particular, the memory spectrum for each scenario is compared with the sensitivity of next-generation detectors, namely DECIGO and ET-D. Physical properties spread over a broad-band region, emphasizing the importance of combined and wide-band observations. We also simulate GW memory based on nearby, realistic scenarios and demonstrate its detectability.

astro-ph.HE

Probing Pion Valence Quark Distribution with Beam-charge Asymmetry of Pion-induced $J/ψ$ Production

We consider the beam-charge asymmetry of the $J/ψ$ production cross sections in $π^-$- versus $π^+$-induced reactions on proton or nuclear targets. We show that the $J/ψ$ production cross section difference between $π^-$ and $π^+$ beams impinging on a proton target has a positive sign with a magnitude proportional to the product of pion's valence quark distribution, $V_π$, and proton's up and down valence quark distribution difference, $u^V - d^V$. The existing $J/ψ$ production data for $π^- + p$ and $π^+ + p$ at 39.5 and 200 GeV/c are consistent with the expected positive beam-charge asymmetry. The magnitude of the asymmetry is compared with calculations performed within two theoretical frameworks, the Color Evaporation Model (CEM) and the Non-Relativistic QCD (NRQCD) formalism. We also examine the beam-charge dependence for pion-induced $J/ψ$ production cross sections measured on the neutron-rich platinum target, and find good agreement between the data and theory for both the negative sign and the magnitude of the beam-charge asymmetry. The comparison between data and theoretical calculations for both proton and platinum targets suggests that the beam-charge asymmetry in pion-induced $J/ψ$ production is a viable method of accessing the valence quark distribution of the pion.

hep-ph

Computing the Wave: Where the Gravitational Wave Community benefits from High-Energy Physics, and where it differs ?

High-Energy Physics (HEP) and Gravitational Wave (GW) communities serve different scientific purposes. However, their methodologies might potentially offer mutual enrichment through common software developments. A suite of libraries is currently being prototyped and made available at https://git.ligo.org/kagra/libraries-addons/root, extending at no cost the CERN ROOT data analysis framework toward advanced signal processing. We will also present a performance benchmark comparing the FFTW and KFR library performances.

astro-ph.IM

Parameter estimation of protoneutron stars from gravitational wave signals using the Hilbert-Huang transform

Core-collapse supernovae (CCSNe) are potential multimessenger events detectable by current and future gravitational wave (GW) detectors. The GW signals emitted during these events are expected to provide insights into the explosion mechanism and the internal structures of neutron stars. In recent years, several studies have empirically derived the relationship between the frequencies of the GW signals originating from the oscillations of protoneutron stars (PNSs) and the physical parameters of these stars. This study applies the Hilbert-Huang transform (HHT) [Proc. R. Soc. A 454, 903 (1998)] to extract the frequencies of these modes to infer the physical properties of the PNSs. The results exhibit comparable accuracy to a short-time Fourier transform-based estimation, highlighting the potential of this approach as a complementary method for extracting physical information from GW signals of CCSNe.

gr-qc