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:20240310T070000
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
DTSTART:20231105T060000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:682a10c2a0284
DTSTART;TZID=America/Toronto:20241031T140000
SEQUENCE:0
TRANSP:TRANSPARENT
DTEND;TZID=America/Toronto:20241031T150000
URL:/combinatorics-and-optimization/events/algebraic-an
 d-enumerative-combinatorics-seminar-joseph
SUMMARY:Algebraic and enumerative combinatorics seminar-Joseph Fluegemann
CLASS:PUBLIC
DESCRIPTION:Summary \n\nTITLE:Smooth points on positroid varieties and plan
 ar N=4\nsupersymmetric Yang-Mills theory\n\nSpeaker\n Joseph Fluegemann\n\
 nAffiliation\n University of À¶Ý®ÊÓƵ\n\nLocation\n MC 5479\n\n ABSTRACT:
  Positroid varieties are subvarieties in the Grassmannian\ndefined by cycl
 ic rank conditions and which are related to Schubert\nvarieties. We will p
 rovide a criterion for whether positroid varieties\nare smooth at certain 
 distinguished points\, and we will show that this\ninformation is sufficie
 nt to determine smoothness for the entire\npositroid variety. This will in
 volve looking at combinatorial diagrams\ncalled \"affine pipe dreams.\" We
  can also form a partial order on\npositroid varieties given by deletion a
 nd contraction\, such that there\nis closure for smooth positroid varietie
 s\, and we will characterize\nthe minimal singular elements in this order.
  Finally\, we will discuss\na couple of connections between the techniques
  of this work and planar\nN=4\n\nSYM: the BCFW bridge decomposition and in
 verse soft factors.\n\nTHERE WILL BE A PRE-SEMINAR PRESENTING RELEVANT BAC
 KGROUND AT THE\nBEGINNING GRADUATE LEVEL STARTING AT 1PM\,\n 
DTSTAMP:20250518T165426Z
END:VEVENT
END:VCALENDAR