BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Drupal iCal API//EN
X-WR-CALNAME:Events items teaser
X-WR-TIMEZONE:America/Toronto
BEGIN:VTIMEZONE
TZID:America/Toronto
X-LIC-LOCATION:America/Toronto
BEGIN:DAYLIGHT
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
DTSTART:20250309T070000
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
DTSTART:20241103T060000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:69cf6b77641a3
DTSTART;TZID=America/Toronto:20250317T113000
SEQUENCE:0
TRANSP:TRANSPARENT
DTEND;TZID=America/Toronto:20250317T123000
URL:https://uwaterloo.ca/combinatorics-and-optimization/events/algebraic-gr
 aph-theory-sho-suda
SUMMARY:Algebraic Graph Theory-Sho Suda
CLASS:PUBLIC
DESCRIPTION:TITLE: Symmetric and Skew-Symmetric Signing for Graphs\n\nSPEA
 KER:\n Sho Suda\n\nAFFILIATION:\n\nNational Defense Academy of Japan\n\nLO
 CATION:\n Please contact Sabrina Lato for Zoom link.\n\nABSTRACT:\n\nWe 
 consider symmetric and skew-symmetric signings for graphs. A\nsigning for 
 a graph G = (V\, E) is a mapping σ : (x\, y) | x\, y in V \\}\nto {0\, ±
  1} with the following properties:\n\n* σ(x\, y) ≠ 0 if and only if {x\
 , y} in E\,\n * σ(x\, y) = σ(y\, x) for any distinct x\, y in V with {x\
 , y} in E.\n\nFor a signing σ of a graph\, we define the signed adjacency
  matrix\nA_σ of the graph\, where the (x\, y)-entry of A_σ is equal to 
 σ(x\,\ny). We study the problem of finding lower bounds for the spectral\
 nradius of A_σ and aim to determine a signing for a given graph such\ntha
 t its spectral radius is the smallest among all possible signings\nof that
  graph. A signing of a small spectral radius plays an important\nrole in c
 onstructing Ramanujan graphs.  Additionally\, we consider a\nvariation of
  signing\, which we call skew-symmetric signing for graphs.\n\nThis talk i
 s based on joint work with Jack Koolen and Hadi Kharaghani.
DTSTAMP:20260403T072543Z
END:VEVENT
END:VCALENDAR