Amazigh Ouzriat

Gravitational-wave astronomy and cosmology. I detect compact binary mergers in LIGO-Virgo-KAGRA data and I am now turning those detections into measurements of the expansion history of the Universe.

JSPS Postdoctoral Fellow at the Research Center for the Early Universe (RESCEU)
The University of Tokyo · Cannon group · KAGRA Collaboration
Curriculum vitae Publications
Portrait of Amazigh Ouzriat

Research

My research focuses on compact binary coalescences detected by ground-based gravitational-wave detectors. My work spans the complete observational chain: extracting faint signals from noisy detector data, characterizing noise artifacts and leveraging binary populations for cosmological inference.

Following my Ph.D. at IP2I Lyon (Université Claude Bernard Lyon 1) under Dr. Viola Sordini, I am now a JSPS Postdoctoral Fellow at RESCEU, The University of Tokyo, in Prof. Kipp Cannon's group, developing novel statistical methods for gravitational-wave cosmology.

Gravitational-wave cosmology

At RESCEU, I develop advanced statistical frameworks to infer cosmological parameters — including the Hubble constant — from compact binary populations. This work rigorous models selection effects and search pipeline sensitivities, building upon my prior studies on LIGO-Virgo observations and prospects for next-generation observatories (Einstein Telescope, LISA).

Compact binary coalescence searches

As lead analyst of the offline MBTA search during the first part of the fourth LVK observing run (O4a), I spearheaded search sensitivity campaigns, background estimation and the integration of iDQ data-quality metrics into candidate ranking. These results directly contributed to GWTC-4.0 and discovery papers for exceptional events, such as GW231123.

Sky localization and detector characterization

I quantify how adding Virgo to the LIGO network enhances low-latency sky localization and assess how noise transients degrade candidate significance. In parallel, I contribute to event validation and data-quality products that ensure candidate reliability for downstream multi-messenger follow-up.

Experimental nuclear & detector physics

During my Master's research at CEA Saclay, I designed and characterized a portable thermal-neutron source for rare-event detector calibration, directly facilitating the observation of a nuclear recoil peak at the sub-keV scale.

Selected publications

Co-author of 57 publications, including 36 articles in peer-reviewed journals and 52 co-authored papers within the Virgo Collaboration. The complete list is on INSPIRE-HEP.

Pipeline, methods and Ph.D. work

2025
Characterizing low-latency sky localization in multi-detector gravitational-wave networks
A. Ouzriat, V. Sordini, F. Di Renzo · preprint
First-author study of the impact of Virgo and of glitches on sky localization.
arXiv:2510.21930
2025
The MBTA pipeline for detecting compact binary coalescences in the fourth LIGO-Virgo-KAGRA observing run
C. Alléné et al. · Class. Quantum Grav. 42, 105009
Role: lead analyst of the offline MBTA search in O4a.
DOI arXiv:2501.04598
2025
Search for compact binary coalescences during the first part of the fourth LIGO-Virgo-KAGRA observing run
A. Ouzriat · Ph.D. thesis, Université Claude Bernard Lyon 1
HAL
2025
Compact binary coalescence sensitivity estimates with injection campaigns during the LVK fourth observing run
R. Essick et al. · Phys. Rev. D 112, 102001
Role: production of the MBTA injection results.
DOI arXiv:2508.10638

GWTC-4.0 and open data

2025
GWTC-4.0: Updating the Gravitational-Wave Transient Catalog with observations from the first part of the fourth observing run
LVK Collaboration · preprint
Role: production of MBTA detections.
arXiv:2508.18082
2025
GWTC-4.0: Methods for identifying and characterizing gravitational-wave transients
LVK Collaboration · preprint
Role: paper writing team, event validation and data quality.
arXiv:2508.18081
2025
GWTC-4.0: Population properties of merging compact binaries
LVK Collaboration · preprint
Role: MBTA simulations used to model selection effects in the population analysis.
arXiv:2508.18083
2025
Open data from LIGO, Virgo and KAGRA through the first part of the fourth observing run
LVK Collaboration · preprint
Role: paper writing team, detector characterization.
arXiv:2508.18079

Exceptional events

2025
GW231123: a binary black hole merger with total mass 190–265 M☉
LVK Collaboration · Astrophys. J. Lett. 993, L25
Role: production of MBTA detection results.
DOI arXiv:2507.08219
2025
GW241011 and GW241110: exploring binary formation and fundamental physics with asymmetric, high-spin black hole coalescences
LVK Collaboration · Astrophys. J. Lett. 993, L21
Role: paper writing team, analysis of signal significance.
DOI
2024
Observation of gravitational waves from the coalescence of a 2.5–4.5 M☉ compact object and a neutron star
LVK Collaboration · Astrophys. J. Lett. 970, L34
Role: production of MBTA detection results.
DOI arXiv:2404.04248

Experimental nuclear and particle physics

2023
Observation of a nuclear recoil peak at the 100 eV scale induced by neutron capture
H. Abele et al. · Phys. Rev. Lett. 130, 211802
Role: main developer of the portable thermal-neutron source and simulations.
DOI arXiv:2211.03631

LIGO-Virgo-KAGRA Collaboration Roles

Communications

Nov 2025 · Tokyo, Japan

Unveiling the sky with gravitational waves: discoveries from GWTC-4

International Conference on the Physics of the 2 Infinities

Feb 2025 · Cascina, Italy

Impact of Virgo inclusion on GW sky localization and effect of glitches

Virgo Collaboration Meeting

Sep 2024 · Barcelona, Spain

Search for compact binary coalescences using the offline MBTA pipeline

LIGO-Virgo-KAGRA Collaboration Meeting

Jul 2024 · Noirmoutier, France

Observations of compact binary coalescences by the LVK Collaboration

International Conference “Exploring the Dark Side of the Universe: Tools”

Mar 2024 · Louisiana, USA

First results of the standard MBTA offline search during the first half of the fourth observing run (O4a)

LIGO-Virgo-KAGRA Collaboration Meeting

Sep 2023 · Toyama, Japan

Investigating iDQ integration into the MBTA offline search

LIGO-Virgo-KAGRA Collaboration Meeting

Apr 2023 · Cascina, Italy

Investigating iDQ integration into the MBTA offline search

Virgo Collaboration Meeting

Jul 2022 · Saclay, France

Open physics problems during the International Physicist Tournament

Seminar, CEA Institute of Research into the Fundamental Laws of the Universe (IRFU)

Teaching

Teaching assistant at Université Claude Bernard Lyon 1 (Faculty of Sciences and Technology) throughout my Ph.D., from 2023 to 2025, in three undergraduate courses covering electromagnetism, general physics and scientific programming.

PHY2000E

Fundamentals of Physics

  • Spring 2024 and Spring 2025
  • Undergraduate medical students (physics minor)
  • Optics, electromagnetism, mechanics and the mathematical tools they rely on.
PHY2021L

Electromagnetism

  • Fall 2023 and Fall 2024
  • Physics and Chemistry undergraduates
  • Electrostatics, magnetostatics, electromagnetic induction and electromagnetic waves.
TVL1212L

Initiation to Python

  • Fall 2023
  • Physics and Chemistry undergraduates
  • Programming fundamentals, from syntax to statistics and plotting, for scientific data handling.

Academic Background

  • 2022 – 2025Ph.D., gravitational-wave astronomy, IP2I, Université Claude Bernard Lyon 1. Advisor: Viola Sordini.
  • 2020 – 2022M.Sc., fundamental physics (nuclei, particles, astroparticles and cosmology), Paris-Saclay University.
  • 2017 – 2020B.Sc., physics, Université Claude Bernard Lyon 1.

Skills

PythonC/C++RSQLBashGit, CI/CDSLURMHTCondorDockerKubernetesNumPypandasscikit-learnPyTorch

Languages: Berber (native), Arabic, French, English (fluent).