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SUMMARY:Diffeomorphism groups of intermediate regularity
DTSTART:20180308T130000
DTEND:20180308T140000
DTSTAMP:20260501T141721Z
UID:9ff2302ed2b692e2432c8b138df1c82c11fed4d7e620542d0a9a462f
CATEGORIES:Conferences - Seminars
DESCRIPTION:Abstract: Let $M$ be the interval or the circle. For each real
  number $\\alpha \\in [1\,\\infty)$\, write $\\alpha=k+\\tau$\, where $k$ 
 is the floor function of $\\alpha$. I will discuss a construction of a fin
 itely generated group of diffeomorphisms of $M$ which are $C^k$ and whose 
 $k^{th}$ derivatives are $\\tau$--H\\"older continuous\, but which are adm
 it no algebraic smoothing to any higher H\\"older continuity exponent. In 
 particular\, such a group cannot be realized as a group of $C^{k+1}$ diffe
 omorphisms of $M$. I will discuss the construction of countable simple gro
 ups with the same property\, and give some applications to continuous grou
 ps of diffeomorphisms. This is joint work with Sang-hyun Kim.
LOCATION:MA A3 30 https://plan.epfl.ch/?room=MAA330
STATUS:CONFIRMED
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