BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20250803T160052EDT-2863RSFvbn@132.216.98.100
DTSTAMP:20250803T200052Z
DESCRIPTION:Title: Can we geometrically sense the shape of a molecule?\n\nA
 bstract: Can we hear the shape of a drum? This question was negatively ans
 wered decades ago by many authors including Gordon\, Webb\, Wolpert\, who 
 constructed non-isometric planar shapes that have the identical eigenvalue
 s of the Laplace operator (Bull. AMS\, v.27 (1992)\, p.134-138). The more 
 general question: can we sense the shape of a rigid object such as a cloud
  of atomic centers representing a molecule? The SSS theorem from school ge
 ometry says that any triangles (clouds of 3 unordered points) are congruen
 t (isometric) if and only if they have the same three sides (ordered by le
 ngth). An extension of this theorem to more points in higher dimensions wa
 s practical only for clouds of m ordered points\, which are uniquely deter
 mined up to isometry by a matrix of m x m distances. If points are unorder
 ed\, comparing m! matrices under all permutations of m points is impractic
 al. We will define a complete (under rigid motion) and Lipschitz continuou
 s invariant for all clouds of m unordered points\, which is computable in 
 polynomial time of m in any fixed Euclidean space\, published in CVPR 2023
 . For the QM9 database of 130K+ molecules with 3D coordinates\, the more r
 ecent invariants distinguished all clouds of atomic centers without chemic
 al elements\, which confirmed that the shape of a molecule including its c
 hemistry is determined from sufficiently precise atomic geometry. The rele
 vant papers are at https://kurlin.org/research-papers.php#Geometric-Data-S
 cience.\n\nCRM\, Pavillion André-Aisenstadt\, room 5340\n\nOpen on Zoom\n
DTSTART:20241018T140000Z
DTEND:20241018T150000Z
SUMMARY:Vitaliy Kurlin (University of Liverpool)
URL:/mathstat/channels/event/vitaliy-kurlin-university
 -liverpool-360491
END:VEVENT
END:VCALENDAR