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:69cf7a2cbcb85
DTSTART;TZID=America/Toronto:20250313T140000
SEQUENCE:0
TRANSP:TRANSPARENT
DTEND;TZID=America/Toronto:20250313T150000
URL:https://uwaterloo.ca/combinatorics-and-optimization/events/algebraic-an
 d-enumerative-combinatorics-seminar-steve
SUMMARY:Algebraic and enumerative combinatorics seminar-Steve Melczer
CLASS:PUBLIC
DESCRIPTION:TITLE: Positivity of P-Recursive Sequences Satisfying Linear\nR
 ecurrences\n\nSpeaker\n Steve Melczer\n\nAffiliation\n University of Water
 loo\n\nLocation\n MC 5479\n\n ABSTRACT: Whether it is decidable to deter
 mine when sequences\nsatisfying linear recurrences with constant coefficie
 nts have all\npositive terms is a notorious problem in enumerative combina
 torics\nthat has essentially been open for around 90 years. Nevertheless\,
  a\n\"meta-principle\" states that all such sequences arising from\ncombin
 atorial counting problems belong to a special class where\npositivity (and
  more general asymptotic\n\nbehaviour) is decidable. Here we discuss new s
 oftware for determining\npositivity for sequences satisfying linear recurr
 ences with\n*polynomial* coefficients. Originally motivated by a novel app
 roach to\nproving genus one solution uniqueness for the Canham model for\n
 biomembrane shapes\, our algorithm combines rigorous numeric analytic\ncon
 tinuation of functions satisfying linear ODEs with singularity\nanalysis t
 echniques from analytic combinatorics. The main talk will be\npresented us
 ing a live Sage Jupyter notebook\, and audience members who\nhave access t
 o Sage with a recent version of the ore_algebra package\ninstalled (availa
 ble at\n\nhttps://github.com/mkauers/ore_algebra) will be able to follow a
 long\nand play with the package during the talk.\n\nTHERE WILL BE A PRE-SE
 MINAR PRESENTING RELEVANT BACKGROUND AT THE\nBEGINNING GRADUATE LEVEL STAR
 TING AT 1PM\,
DTSTAMP:20260403T082828Z
END:VEVENT
END:VCALENDAR