BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//University of California\, Berkeley//UCB Events Calendar//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:America/Los_Angeles
BEGIN:STANDARD
TZOFFSETFROM:-0700
TZOFFSETTO:-0800
DTSTART:19701029T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:19700402T020000
TZOFFSETFROM:-0800
TZOFFSETTO:-0700
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20190908T210013Z
DTSTART;TZID=America/Los_Angeles:20191031T161000
DTEND;TZID=America/Los_Angeles:20191031T170000
TRANSP:OPAQUE
SUMMARY:Mathematics Department Colloquium: Recent advances on `hearing the shape of a drum'
UID:128187-ucb-events-calendar@berkeley.edu
ORGANIZER;CN="UC Berkeley Calendar Network":
LOCATION:60 Evans Hall
DESCRIPTION:Steve Zelditch\, Northwestern University\n\nIn 1966\, M. Kac posed the problem\, `Can one hear the shape of a drum'\, i.e. can one determine a bounded plane domain from its Dirichlet (or\, Neumann) eigenvalues? He proved that indeed one can determine a disk from its spectrum. Disks remained the only domains known to be determined by their eigenvalues until recently. My talk concerns a recent result due to Hamid Hezari and myself\, showing that ellipses of small eccentricity are also determined by their eigenvalues. The proof uses some recent advances in dynamical inverse theory due to Avila\, de Simoi\, Kaloshin\, Sorrentino\, Wei and others which partly resolve another famous inverse problem of G.D. Birkhoff: are ellipses the only billiard tables with integrable billiards? The solution of the inverse eigenvalue problem is based on their result that ellipses of small eccentricity are the only nearly circular billiard tables with rationally integrable billiards. My talk will review both the eigenvalue and dynamical inverse spectral results.
URL:http://events.berkeley.edu/index.php/calendar/sn/pubaff.html?event_ID=128187&view=preview
SEQUENCE:0
CLASS:PUBLIC
CREATED:20190908T210013Z
LAST-MODIFIED:20190927T062845Z
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
X-MICROSOFT-CDO-INSTTYPE:0
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-OWNERAPPTID:-1
END:VEVENT
END:VCALENDAR