Magdalena Sieniawska



Centre for Cosmology, Particle Physics and Phenomenology - CP3
Université catholique de Louvain
2, Chemin du Cyclotron - Box L7.01.05
B-1348 Louvain-la-Neuve


UCL member card
Research directions:
Data analysis in HEP, astroparticle and GW experiments

Experiments and collaborations:

Active projects
Multi-messenger studies of transient sources
Giacomo Bruno, Karlijn Kruiswijk, Andrew Miller, Magdalena Sieniawska, Jishnu Suresh, Gwenhaël Wilberts Dewasseige

This project aims at studying astrophysical phenomena combining different messengers, mainly neutrinos and gravitational waves.
Virgo - data analysis - searches with continuous gravitational waves
Giacomo Bruno, Federico De Lillo, Antoine Depasse, Andrew Miller, Magdalena Sieniawska

Asymmetrically rotating neutron stars (NS) are the canonical sources of continuous gravitational
waves, which is the name given to long-duration, almost monochromatic GW signals. There has
been a growing number of other sources of similar signals, which are in general very weak, but
because they are almost monochromatic and of very long duration, they can be integrated over
observation periods lasting up to years and become observable. Sophisticated corrections need to be devised
in order to capture these long and weak signals. These corrections
take into account the deviation from perfect mono-chromaticity of the signal frequency spectrum, which are caused either
by the source dynamics of by the relative movement of the source and the detector.

Our group has been setting up a search for new ultra-light bosons, which could be dark matter (DM) candidates and could accumulate around spinning black holes (BH) via superradiance. In particular, we have been
focusing on the search for vector boson accumulating in known X-ray binaries in our galaxy.
In addition to the movement of the earth, the signal will be modulated by the Doppler effect due to the motion of the source black hole (BH)
around its barycenter.

Our group is also active on studies aiming to detect planetary-mass (10^-7 to 10^-2 M⊙) primordial BHs (PBH) with continuous-wave
methods. The method applies to binary
systems that are still far from the merger and has allowed to constrain the rates and abundance of PBHs in the universe. Limits on the
fraction of DM made of such PBHs (in the galactic halo, in the galactic centre, and in the solar
system vicinity) have also been calculated, for LIGO/Virgo as well as ET.

Ultra-light (10^-13 - 10^-11 eV) bosons could interact with the baryons and leptons in the LIGO/Virgo
mirrors, causing a constant, narrowband signal in the instruments, very similar to a quasi-monochromatic GW.
This project displays synergy between particle physics and GW physics and shows that we can
now directly look for DM candidates with GW instruments. Both short-author list and Collaboration-wide publications have resulted from this project.
Publications in IRMP
All my publications on Inspire

Number of publications as IRMP member: 6
Last 5 publications


IRMP-CP3-22-53: Probing Ensemble Properties of Vortex-avalanche Pulsar Glitches with a Stochastic Gravitational-Wave Background Search
De Lillo, Federico and Suresh, Jishnu and Depasse, Antoine and Sieniawska, Magdalena and Miller, Andrew L. and Bruno, Giacomo

[Abstract] [PDF]
Available on arXiv, submitted to Physical Review D.
Refereed paper. December 1.


CP3-21-24: Search for intermediate mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo
Abbott, Rich and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-23: Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-22: Searches for continuous gravitational waves from young supernova remnants in the early third observing run of Advanced LIGO and Virgo
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.
CP3-21-21: Search for lensing signatures in the gravitational-wave observations from the first half of LIGO-Virgo's third observing run
Abbott, R. and others

[Abstract] [PDF] [Journal] [Dial]
Refereed paper. June 18.

More publications