BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:Isaac Newton Institute Seminar Series
SUMMARY:Applications of Arnold's variational principle to
the stability of vortices in ideal and viscous flo
ws - Thierry Gallay (Université Grenoble Alpes)
DTSTART;TZID=Europe/London:20220216T094500
DTEND;TZID=Europe/London:20220216T104500
UID:TALK167396AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/167396
DESCRIPTION:We revisit Arnold's variational approach to the st
ability of steady-state solutions of the two-dimen
sional Euler equations. In thecase of planar vorti
ces\, we study in detail the quadratic form that r
epresents the second variation of the energy on th
e isovorticalsurface. We show in particular that\,
for a large class of radially symmetric vortices
with strictly decreasing profile\, the secondvaria
tion is negative definite for all perturbations th
at preserve the total circulation. We use that pro
perty to give a new stabilityproof for the Oseen v
ortex as a self-similar solution of the 2D Navier-
Stokes equations\, and to investigate the vanishin
g viscositylimit of axisymmetric vortex rings. Thi
s talk is based on joint work with V. Sverak.
LOCATION:Seminar Room 1\, Newton Institute
CONTACT:
END:VEVENT
END:VCALENDAR