BEGIN:VCALENDAR VERSION:2.0 PRODID:-//IAP calendar product//iap.fr// CALSCALE:GREGORIAN X-WR-CALNAME:GReCO seminars BEGIN:VTIMEZONE TZID:Europe/Paris BEGIN:STANDARD DTSTART:19961027T030000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZNAME:CET TZOFFSETFROM:+0200 TZOFFSETTO:+0100 END:STANDARD BEGIN:DAYLIGHT DTSTART:19810329T020000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3 TZNAME:CEST TZOFFSETFROM:+0100 TZOFFSETTO:+0200 END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT SUMMARY:Tidal effects in eccentric compact binaries DTSTART;TZID=Europe/Paris:20260216T110000 DTEND;TZID=Europe/Paris:20260216T120000 DTSTAMP:20260216T105100Z UID:2026-02-1611:00:00+00:09"Tidaleffectsineccentriccompactbinaries"_n9a9y Qd2s4alIgl1DJML DESCRIPTION:Quentin Henry (Departament de Física\, Universitat de les Ill es Balears\, IAC3 – IEEC\, Palma\, Espagne)\n\nAbstract: The recent rele ase of the gravitational-wave (GW) transient catalog\nGWTC-4.0 by the LVK Collaboration reports more than 200 compact-binary\ncoalescence events\, a mong which 7–9 systems contain at least one neutron\nstar. Unlike black holes\, neutron stars experience tidal interactions\nthat leave measurable imprints on the GW signal\, allowing us to probe\ntheir equation of state . The inspiral of comparable-mass compact\nbinaries is accurately describe d within the post-Newtonian (PN)\napproximation\, which provides the analy tical input for waveform models\nemployed in matched-filtering searches an d parameter estimation. Thus\nfar\, PN results including tidal contributio ns to the gravitational\nwaveform have been provided only for quasi-circul ar binaries.\n\nIn this talk\, I will present the recent derivation of gra vitational\nwaveforms emitted by tidally interacting compact binaries on e ccentric\norbits in the PN framework. These results are ready for implemen tation\nin waveform models. I will discuss the impact of eccentricity–ti dal\ncouplings on the phasing and their potential measurability with curre nt\nground-based detectors. In particular\, I will discuss the GW200105\ne vent\, interpreted as a neutron star–black hole merger\, which entered\n the LIGO–Virgo sensitivity band with a residual orbital eccentricity of\ napproximately 0.13.\n\nSlides (PDF): https://tinyurl.com/267r43pr LOCATION:Salle des séminaires Évry Schatzman END:VEVENT BEGIN:VEVENT SUMMARY:de Sitter momentum space DTSTART;TZID=Europe/Paris:20260223T110000 DTEND;TZID=Europe/Paris:20260223T120000 DTSTAMP:20260223T105100Z UID:2026-02-2311:00:00+00:09"deSittermomentumspace"_GGKrmRhmamXk8ZCVXYdq DESCRIPTION:Arthur Poisson\nInstitut d'Astrophysique de Paris\, Paris\, Fr ance\n\n\nAbstract: In many inflationary scenarios\, primordial correlatio n functions are encoded in late-time observables in de Sitter spacetime\, where even the simplest processes already involve highly nontrivial time i ntegrals. I will show that this difficulty can be overcome by introducing a new momentum-space representation adapted to de Sitter isometries. This construction is based on diagonalizing the Casimir operator rather than th e Hamiltonian\, effectively trading the usual (d+1)-dimensional Fourier sp ace for the Kontorovich–Lebedev–Fourier (KLF) space. I will also show practical advantages of this description: quadratic dynamics provides a si mple propagator analogous to flat space\, and the nested time integrals tu rn into frequency-space integrals over meromorphic functions.\n\nhttp://ww w.iap.fr/vie_scientifique/journal-clubs/Journal-club_GReCO/2026/presentati ons/de\n LOCATION:Salle des séminaires Évry Schatzman END:VEVENT BEGIN:VEVENT SUMMARY:Gravitational lensing beyond the eikonal approximation DTSTART;TZID=Europe/Paris:20260302T110000 DTEND;TZID=Europe/Paris:20260302T120000 DTSTAMP:20260302T105100Z UID:2026-03-0211:00:00+00:09"Gravitationallensingbeyondtheeikonalapproxima tion"_hlTwTrWe7nrxPIGvnQX3 DESCRIPTION:Emma Bruyère\nInstitut d'Astrophysique de Paris\, Paris\, Fra nce\n\n\nAbstract: Waves propagating through a gravitational potential exh ibit wave-\noptics effects when their wavelength is not significantly smal ler than the lensing scales. We study the propagation of a scalar wave\, g overned by the Klein-Gordon equation in curved spacetime\, to focus on eff ects on amplitude and phase\, while leaving aside the issue of wave polari zation which affects electromagnetic and gravitational waves. \nUsing the Newman-Penrose formalism\, we obtain the first corrections beyond the geom etric optics in the expansion in the inverse frequency. We check\nthe anal ytic results by solving numerically the equations dictating the evolution of the corrections either in the vicinity of a Schwarzschild black hole or through a transparent star.\n LOCATION:Salle des séminaires Évry Schatzman END:VEVENT BEGIN:VEVENT SUMMARY:GReCO Seminar (TBA) DTSTART;TZID=Europe/Paris:20260316T110000 DTEND;TZID=Europe/Paris:20260316T120000 DTSTAMP:20260316T105100Z UID:2026-03-1611:00:00+00:09Titleandsummarytocome_uWgTJQuMW3hypNZv5Wy3 DESCRIPTION:Amelia Drew\nInternational Centre for Theoretical Physics \, T rieste\, Italie\n\n\n\nhttp://www.iap.fr/vie_scientifique/journal-clubs/jo urnal-clubs.php?nom=Journal-club_GReCO&annee=2026&langue=en LOCATION:Salle des séminaires Évry Schatzman END:VEVENT BEGIN:VEVENT SUMMARY:GReCO Seminar (TBA) DTSTART;TZID=Europe/Paris:20260323T110000 DTEND;TZID=Europe/Paris:20260323T120000 DTSTAMP:20260323T105100Z UID:2026-03-2311:00:00+00:09Titleandsummarytocome_JypaatRDbXUWr6ReE4gw DESCRIPTION:Marc Geiller\n\n\nhttp://www.iap.fr/vie_scientifique/journal-c lubs/journal-clubs.php?nom=Journal-club_GReCO&annee=2026&langue=en LOCATION:Salle des séminaires Évry Schatzman END:VEVENT BEGIN:VEVENT SUMMARY:GReCO Seminar (TBA) DTSTART;TZID=Europe/Paris:20260504T150000 DTEND;TZID=Europe/Paris:20260504T160000 DTSTAMP:20260504T145100Z UID:2026-05-0415:00:00+00:09Titleandsummarytocome_rFravRoh6Jp2z5Zg0g0X DESCRIPTION:Rocky Kolb\n\n\nhttp://www.iap.fr/vie_scientifique/journal-clu bs/journal-clubs.php?nom=Journal-club_GReCO&annee=2026&langue=en LOCATION:Salle des séminaires Évry Schatzman END:VEVENT END:VCALENDAR