BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:Isaac Newton Institute Seminar Series
SUMMARY:Symmetrically coloured Gaussian graphical models w
ith toric vanishing ideals - Jane Coons (Universit
y of Oxford)
DTSTART;TZID=Europe/London:20240124T114500
DTEND;TZID=Europe/London:20240124T124500
UID:TALK208063AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/208063
DESCRIPTION:Gaussian graphical models are multivariate Gaussia
n statistical models in which a graph encodes cond
itional independence relations among the random va
riables. Adding colors to this graph allows us to
describe situations where some entries in the conc
entration matrices in the model are assumed to be
equal. In this talk\, we focus on RCOP models\, in
which this coloring is obtained from the orbits o
f a subgroup of the automorphism group of the unde
rlying graph. We show that when the underlying blo
ck graph is a one-clique-sum of complete graphs\,
the Zariski closure of the set of concentration ma
trices of an RCOP model on this graph is a toric v
ariety. We also give a Markov basis for the vanish
ing ideal of this variety in these cases. Finally\
, we present preliminary results on the ideals of
RCOP graphs which are not block graphs. This is jo
int work with Aida Maraj\, Pratik Misra and Miruna
-Stefana Sorea.
LOCATION:Seminar Room 1\, Newton Institute
CONTACT:
END:VEVENT
END:VCALENDAR