BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Preparing for the future gravitational wave burst searches with ma chine learning techniques DTSTART;VALUE=DATE-TIME:20210902T154500Z DTEND;VALUE=DATE-TIME:20210902T160000Z DTSTAMP;VALUE=DATE-TIME:20260812T025853Z UID:indico-contribution-2307-15511@indico.ific.uv.es DESCRIPTION:Speakers: Sophie Bini (Univ. Trento)\nGeneric searches for gra vitational wave bursts are a powerful discovery tool and in the near futur e they are expected to unveil new phenomena. The coherentWaveBurst (cWB) p ipeline is a state-of-the-art burst search pipeline\, and it has been used to analyze the data from the latest observing runs of the LIGO/Virgo dete ctors.\nIn preparation for the next observing run\, which will include KAG RA detector\, we are investigating several improvements involving also the application of cutting edge machine learning techniques. A decision tree algorithm will address the post production analysis of the candidate event s\, upgrading the selection criteria and ranking procedures applied so far . Moreover\, an autoencoder neural network will pinpoint morphologies asso ciated to well known noise transients\, mitigating their impact.\nWe show that both these procedures are robust and do not limit the general charact er of the search. We present preliminary results on public LIGO-Virgo data for widely different burst morphologies\, ranging from extreme ad-hoc sig nals to more astrophysically inspired gravitational-wave transients.\n\nht tps://indico.ific.uv.es/event/6178/contributions/15511/ LOCATION: URL:https://indico.ific.uv.es/event/6178/contributions/15511/ END:VEVENT BEGIN:VEVENT SUMMARY:Looking for Core-Collapse Supernovae with Gravitational Waves and Low-energy Neutrinos DTSTART;VALUE=DATE-TIME:20210902T154500Z DTEND;VALUE=DATE-TIME:20210902T160000Z DTSTAMP;VALUE=DATE-TIME:20260812T025853Z UID:indico-contribution-2307-15503@indico.ific.uv.es DESCRIPTION:Speakers: Giulia Pagliaroli (INFN)\nCore-collapse supernovae a re fascinating astrophysical objects for multimessenger studies. Gravitati onal waves (GWs) are expected to play a role in the supernova explosion me chanism\, however their complex modelling makes the detection very challen ging. Low-energy neutrinos will be emitted enormously during the core-coll apse explosion and can help for the gravitational wave counterpart search. In this work we develop a multi-messengers strategy to search for such as trophysical objects by exploiting a global network of both low-energy neut rino and gravitational wave detectors. We also improve the detection poten tial of the neutrino sub-network by exploiting the temporal behaviour of a neutrino burst from a core-collapse supernova. We show that with the pro posed approach neutrino detectors can gain at least 10% of detection effic iency at the distance where their efficiency drops. Then\, we combine the information provided by GW and neutrino in a multi-messenger strategy. I n particular\, we obtain an increase of the probability to detect the GW s ignal from a CCSN at 60 kpc from zero when using only GW analysis to ∼33 % with our combined GW-ν approach.\n\nhttps://indico.ific.uv.es/event/617 8/contributions/15503/ LOCATION: URL:https://indico.ific.uv.es/event/6178/contributions/15503/ END:VEVENT BEGIN:VEVENT SUMMARY:Search for long-duration transient gravitational waves from glitch ing pulsars during LIGO-Virgo third observing run DTSTART;VALUE=DATE-TIME:20210902T154000Z DTEND;VALUE=DATE-TIME:20210902T155500Z DTSTAMP;VALUE=DATE-TIME:20260812T025853Z UID:indico-contribution-2307-15502@indico.ific.uv.es DESCRIPTION:Speakers: Luana Modafferi (Universitat de les Illes Balears)\n Pulsars are spinning neutron stars which emit an electromagnetic beam. We expect pulsars to slowly decrease their rotational frequency. However\, su dden increases of the rotational frequency have been observed from differe nt pulsars. These events are called “glitches”\, and they are followed by a relaxation phase with timescales from days to months. Gravitational waves (GWs) emission may follow these peculiar events. We give an overview of an analysis of GW data from the Advanced LIGO and Virgo third observin g run (O3) searching for transient GW signals lasting hours to months afte r glitches in known pulsars during the 2019-2020 run period. The search me thod consists of placing a template grid in frequency-spindown space with fixed grid spacings. Then\, for each point we compute the transient F-stat istic which is maximized over a set of transient parameters like the durat ion and start time of the potential signals. A threshold on the detection statistic is then set\, and we search for peaks over the parameter space f or each candidate.\n\nhttps://indico.ific.uv.es/event/6178/contributions/1 5502/ LOCATION: URL:https://indico.ific.uv.es/event/6178/contributions/15502/ END:VEVENT BEGIN:VEVENT SUMMARY:All-sky search in early O3 LIGO data for continuous gravitational- wave signals from unknown neutron stars in binary systems DTSTART;VALUE=DATE-TIME:20210902T152500Z DTEND;VALUE=DATE-TIME:20210902T154000Z DTSTAMP;VALUE=DATE-TIME:20260812T025853Z UID:indico-contribution-2307-15499@indico.ific.uv.es DESCRIPTION:Speakers: Rodrigo Tenorio (Universitat de les Illes Balears)\n Rapidly spinning neutron stars are promising sources of persistent gravita tional waves. Detecting such a signal would allow probing of the physical properties of matter under extreme conditions. A significant fraction of t he known pulsar population belongs to binary systems. Searching for unknow n neutron stars in binary systems requires specialized algorithms to addre ss unknown orbital frequency modulations. We present a search for continuo us gravitational waves emitted by neutron stars in binary systems in early data from the third observing run of the Advanced LIGO and Advanced Virgo detectors using the semicoherent\, GPU-accelerated\, BinarySkyHough pipel ine. The search analyzes the most sensitive frequency band of the LIGO det ectors\, 50 - 300 Hz. Binary orbital parameters are split into four region s\, comprising orbital periods of 3 - 45 days and projected semimajor axes of 2 - 40 light-seconds. No detections are reported. We estimate the sens itivity of the search using simulated continuous wave signals\, achieving the most sensitive results to date across the analyzed parameter space.\n\ nhttps://indico.ific.uv.es/event/6178/contributions/15499/ LOCATION: URL:https://indico.ific.uv.es/event/6178/contributions/15499/ END:VEVENT BEGIN:VEVENT SUMMARY:FCF formulation of Einstein equations: local uniqueness and numeri cal accuracy and stability DTSTART;VALUE=DATE-TIME:20210902T151000Z DTEND;VALUE=DATE-TIME:20210902T152500Z DTSTAMP;VALUE=DATE-TIME:20260812T025853Z UID:indico-contribution-2307-15496@indico.ific.uv.es DESCRIPTION:Speakers: Samuel Santos-Pérez (Universitat de València)\nWe present Einstein equations in the so-called Fully Constrained Formulation (FCF). This formulation has two different sectors: the elliptic sector for med by the Hamiltonian and Momentum constraints together with the equation s derived from the gauge choice\, and the hyperbolic sector which encodes the evolution of the rest of degrees of freedom of the spacetime metric in cluding the gravitational waves. We present a modification of both sectors that keeps local uniqueness properties but has a better behaviour regardi ng the relativistic expansion of the equations. We also comment on numeric al properties of this reformulation and some potential applications.\n\nht tps://indico.ific.uv.es/event/6178/contributions/15496/ LOCATION: URL:https://indico.ific.uv.es/event/6178/contributions/15496/ END:VEVENT END:VCALENDAR