BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/Vienna
BEGIN:DAYLIGHT
DTSTART:20270328T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20261025T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:CET
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20261110T151200Z
UID:1794929400@ist.ac.at
DTSTART:20261117T163000
DTEND:20261117T172000
DESCRIPTION:Speaker: Zhihan Jin\nhosted by Matthew Kwan\nAbstract: Abstract
 : Consider the eigenvalues of the adjacency matrix of a graph. If the gra
 ph is a disjoint union of cliques\, the least eigenvalue is 0 or −1. Con
 versely\, what can we say about a graph whose least eigenvalue is small in
  absolute value? In particular\, must such graphs contain a large clique\,
  or even be "close" to a disjoint union of cliques? This question is not o
 nly interesting in its own right\, but also connected to two seemingly unr
 elated topics: Chowla's cosine problem (in harmonic analysis) and the maxi
 mum cut problem (in graph theory). In this talk\, I will discuss our recen
 t result on the eigenvalue question: every graph with average degree d and
  least eigenvalue |λn|≤dt contains a clique of size d1−O(t). I will p
 resent some high-level ideas on how to study the graph structure with help
  of λn. I will also discuss some backgrounds of Chowla's cosine problem a
 s well as the maximum cut problem\, and how our eigenvalue result implies 
 a polynomial improvement on both problems.
LOCATION:Raiffeisen Lecture Hall\, ISTA
ORGANIZER:Stephanie.Dolot@ista.ac.at
SUMMARY:Zhihan Jin: From small eigenvalues to large cuts\, and Chowla's cos
 ine problem
URL:https://talks-calendar.ista.ac.at/events/6760
END:VEVENT
END:VCALENDAR