Giacomo Bruno, Karlijn Kruiswijk, Jeff Lazar, Jonathan Mauro, Emile Moyaux, Christoph Raab, Leonardo Ricca, Marco Scarnera, Per Arne Sevle Myhr, Gwenhaël Wilberts Dewasseige

This project aims at studying astrophysical phenomena combining different messengers, mainly neutrinos, electromagnetic and gravitational waves.

Giacomo Bruno

The stochastic gravitational wave background (SGWB) originates from the superposition of GWs emitted by a large number of
unresolved and uncorrelated sources. Its detection is considered to be one of the ”holy grails” of
GW astronomy, because of its possible cosmological origin and consequently its impact on our
comprehension of the Universe.

The Louvain GW group has been contributing a major effort to the search
for an anisotropic SGWB and the publication of its results. The group is esponsible for one
of the three data analysis algorithms of the LIGO/Virgo/KAGRA (LVK) Collaboration, called broadband radiometer analysis.
Dr J. Suresh has been acting as the anisotropic sub-group chair for the LVK SGWB
group. Not having found any evidence for an SGWB signal, upper limits have been set as a
function of the sky direction.

Millisecond pulsars are one of the potential candidates contributing to the anisotropic stochastic
gravitational-wave background observable in the ground-based gravitational-wave detectors.
We have been contributing to a project aiming to estimate and detect the
stochastic gravitational-wave background produced by millisecond pulsars in the Milky Way.

We have contributed significantly to the published results of a search that looks for
persistent stochastic gravitational-wave sources in all directions of the sky at all frequencies at
which the detectors are sensitive.

Our group has also published a search that is capable of setting constraints on the
ensemble properties of neutron stars, like their average ellipticity, from cross-correlation-based
stochastic gravitational-wave background measurements.