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TZID:Asia/Jerusalem
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DTSTART:20201025T020000
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DTSTART:20200327T020000
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UID:calendar.281695.field_date.0@mathematics.huji.ac.il
DTSTAMP:20200920T103020Z
CREATED:20200515T220018Z
DESCRIPTION:Date: \n\n2:00pm to 3:00pm\n\n\n\n\nSee also: Dynamical & Pro
bability\, Events & Seminars\, Seminars\n\n\nAbstract: One of the first th
ings we learn about a (proper) Gromov hyperbolic geodesic space X is the c
onstruction of the visual boundary of X. An ergodic theorist then learns t
hat for a non-elementary discrete group of isometries G acting properly on
X\, there is an interesting family of \delta_G-quasi-conformal measures o
n the boundary. The parameter \delta_G is called the critical exponent of
G\, and is equal to the exponential growth rate of the orbit Gx in X. Give
n a subgroup H of G\, how do we compare \delta_H and \delta_G? For G with
'good dynamics'\, we expect that \delta_G = \delta_H if and only if H is c
o-amenable in G. This talk will review some recent history of this problem
involving transfer operators for skew product extensions\; and present ou
r new approach which yields the theorem: if the action of G is SPR\, then
we have \delta_G = \delta_H if and only if H is co-amenable in G. What is
particularly appealing about our method is the construction of a 'twisted
Patterson-Sullivan measure'. This is joint work with R. Coulon\, B. Schapi
ra and S. Tapie.Join Zoom MeetingMeeting ID: 910 4725 1047Password: 5w97m2
\n\n Export\n \n\n \nsubscribe iCal
DTSTART;TZID=Asia/Jerusalem:20200602T140000
DTEND;TZID=Asia/Jerusalem:20200602T150000
LAST-MODIFIED:20200601T040028Z
SUMMARY:Dynamics seminar : Rhiannon Dougall (Bristol) Critical exponents fo
r subgroups of isometries of negatively curved spaces
URL;TYPE=URI:https://mathematics.huji.ac.il/event/rhiannon-dougall-bristol
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