BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Instituto de Física Teórica - ECPv6.15.11//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://www.ift.uam-csic.es
X-WR-CALDESC:Events for Instituto de Física Teórica
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Madrid
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20250330T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20251026T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20260329T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20261025T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20270328T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20271031T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Madrid:20260226T110000
DTEND;TZID=Europe/Madrid:20260226T120000
DTSTAMP:20260406T001419
CREATED:20260220T140022Z
LAST-MODIFIED:20260220T140212Z
UID:24432-1772103600-1772107200@www.ift.uam-csic.es
SUMMARY:GRASS Seminar: 'Gravitational Duality at the Lightring\, QNM isospectrality\, and Ringdown Nonlinearities from Penrose Limits'
DESCRIPTION:Gravity\, Supergravity and Superstrings (GRASS) Seminar \nSpeaker: David Pereñiguez (Johns Hopkins U.) \nTitle: ‘Gravitational Duality at the Lightring\, QNM isospectrality\, and Ringdown Nonlinearities from Penrose Limits’ \nAbstract: At high frequencies\, the physics near a black hole’s lightring can be captured by Penrose-limit plane waves adapted to the photon sphere. In this talk\, I will solve exactly the equations for gravitational perturbations in this limit using Penrose’s 2-spinor formalism\, and I will show that the resulting solutions correspond to quasinormal modes (QNMs) in the eikonal regime. I will then prove that gravitational electric–magnetic duality holds on-shell for perturbations at the lightring. This symmetry has long been understood to hold on-shell only for perturbations about flat spacetime. The lightring therefore provides a distinct setting in which it reemerges. In addition\, QNM isospectrality follows as an immediate consequence. I will next extend the analysis to nonlinear gravitational fluctuations\, where the duality is broken\, and compute the excitation of quadratic QNMs\, which are particularly relevant given recent prospects for their detection. I will conclude by discussing further directions in which Penrose limits can be used to sharpen our understanding of lightring physics.
URL:https://www.ift.uam-csic.es/event/grass-seminar-gravitational-duality-at-la-lightring-qnm-isospectrality-and-ringdown-nonlinearities-from-penrose-limits/
LOCATION:IFT Seminar Room/Red Room\, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera\, 13-15\, Fuencarral-El Pardo\, Madrid\, 28049\,\, Spain
CATEGORIES:Scientific activities,Seminars
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Madrid:20260226T150000
DTEND;TZID=Europe/Madrid:20260226T160000
DTSTAMP:20260406T001419
CREATED:20260119T110411Z
LAST-MODIFIED:20260225T154031Z
UID:24224-1772118000-1772121600@www.ift.uam-csic.es
SUMMARY:Seminar: 'Sub-PeV gamma-ray astronomy and its physics'
DESCRIPTION:Title: ‘Sub-PeV gamma-ray astronomy and its physics’ \nSpeaker: Sei Kato (Sorbonne Université\, Institut d’Astrophysique de Paris) \nVenue&Time: Red Room / 15:00 \nAbstract: This talk will focus on the physics that can be explored with sub-PeV gamma-ray astronomy (E > 10^14 eV)\, particularly on the Galactic diffuse gamma rays and the dark matter. Also\, our project called ALPACA\, which aims systematic sub-PeV gamma-ray observations in the southern sky for the first time in the world\, is detailedly presented.
URL:https://www.ift.uam-csic.es/event/seminar-by-sei-kato-institut-dastrophysique-de-paris/
LOCATION:IFT Seminar Room/Red Room\, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera\, 13-15\, Fuencarral-El Pardo\, Madrid\, 28049\,\, Spain
CATEGORIES:Scientific activities,Seminars
END:VEVENT
END:VCALENDAR