BEGIN:VCALENDAR
PRODID:-//PSU Mathematics Department//Seminar iCalendar Generator//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Dynamical systems seminar
X-WR-TIMEZONE:America/New_York
BEGIN:VTIMEZONE
TZID:America/New_York
X-LIC-LOCATION:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:19700308T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:19701101T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150831T153500
DTEND;TZID=America/New_York:20150831T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27208
SUMMARY:Dynamical systems seminar - Slow entropy for smooth flows on surfac
es
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Slow entropy for smo
oth flows on surfaces\nSpeaker: Adam Kanigowski\, Penn State\nAbstract: We
will discuss slow entropy in the class of mixing smooth flows on surfaces
. As a consequence we will find countably many non-isomorphic (disjoint) s
mooth flows. Moreover\, we will show that they don't have finite rank.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150907T153500
DTEND;TZID=America/New_York:20150907T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27209
SUMMARY:Dynamical systems seminar - Labor Day
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Labor Day\nSpeaker:
NO SEMINAR
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150914T153500
DTEND;TZID=America/New_York:20150914T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27210
SUMMARY:Dynamical systems seminar - Coarse hyperbolicity and closed orbits
for quasigeodesic flows
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Coarse hyperbolicity
and closed orbits for quasigeodesic flows\nSpeaker: Steven Frankel\, Yale
University\nAbstract: A flow on a 3-manifold is called quasigeodesic when
each flowline is coarsely comparable to a geodesic. In this talk we will
show that every quasigeodesic flow on a closed hyperbolic 3-manifold has c
losed orbits\, resolving a question of Calegari's.\n\nA quasigeodesic flow
is defined by a tangent condition. In contrast\, a pseudo-Anosov flow is
defined by a transverse condition\; the transverse structure is hyperbolic
in the sense that nearby flowlines diverge in some directions and converg
e in others.\n\nA priori\, these transverse and tangent conditions are unr
elated. However\, when the ambient manifold is hyperbolic\, a quasigeodesi
c flow admits a transverse structure that is remarkably similar to that of
a pseudo-Anosov flow\, except that it is only *coarsely* hyperbolic. Neve
rtheless\, we can prove a sort of closing lemma for coarsely hyperbolic fl
ows\, allowing us to approximate recurrent orbits by closed orbits.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150921T153500
DTEND;TZID=America/New_York:20150921T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27211
SUMMARY:Dynamical systems seminar - Extending cases of smooth rigidity by n
ew technology.
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Extending cases of s
mooth rigidity by new technology.\nSpeaker: Kurt Vinhage\, Penn State\nAbs
tract: Smooth rigidity is a phenomenon which stengthens the structural sta
bility property that is prevalent throughout Anosov systems and normal hyp
erbolicity persistence for partially hyperbolic systems. Such cases were f
irst developed by Katok and Spatzier for Anosov systems and extended to ce
rtain limited cases of partially hyperbolic homogeneous systems by Damjano
vic and Katok. By applying previously undiscovered connections between cla
ssical ideas in topological groups and these systems\, we are able to exte
nd smooth rigidity to a much broader class of homogeneous actions\, includ
ing\, for the first time\, flows on semidirect products. In the case of si
mple Lie groups\, get an optimal result in the case of semisimple actions.
Joint with Zhenqi Wang.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150928T153500
DTEND;TZID=America/New_York:20150928T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27212
SUMMARY:Dynamical systems seminar - Sinai-Ruelle-Bowen measures for non-un
iformly hyperbolic maps.
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Sinai-Ruelle-Bowen m
easures for non-uniformly hyperbolic maps.\nSpeaker: Yakov Pesin\, Penn S
tate
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151005T153500
DTEND;TZID=America/New_York:20151005T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27213
SUMMARY:Dynamical systems seminar - A geometric mechanism for Arnold diffus
ion in the a priori stable case
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: A geometric mechanis
m for Arnold diffusion in the a priori stable case\nSpeaker: Marian Gidea
\, Yeshiva University\nAbstract: We prove the existence of diffusion orbit
s drifting along heteroclinic chains of normally hyperbolic 3-dimensional
cylinders\, under suitable assumptions on the dynamics on the cylinders an
d on their homoclinic/heteroclinic connections. These assumptions are sati
sfied in the a priori stable case of the Arnold diffusion problem. We prov
ide a geometric argument that extends Birkhoff's procedure for constructi
ng connecting orbits inside a zone of instability for a twist map on the
annuls. This is joint work with J.-P. Marco.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151012T153500
DTEND;TZID=America/New_York:20151012T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27214
SUMMARY:Dynamical systems seminar - NO SEMINAR
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: NO SEMINAR
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151019T153500
DTEND;TZID=America/New_York:20151019T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27215
SUMMARY:Dynamical systems seminar - Liftability of hyperbolic measures to Y
oung Towers
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Liftability of hyper
bolic measures to Young Towers\nSpeaker: Stafano Luzzatto\, ICPT Trieste\n
Abstract: Young towers are non-trivial geometric structures which generali
se Markov partitions and can be used to deduce the existence of hyperbolic
invariant measures and to study their statistical properties in some quit
e general settings. A natural and interesting question is whether all hype
rbolic measures have an underlying Young tower structure\, i.e. whether th
ey “lift” to a Young Tower. I will discuss several recent results in t
his direction.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151026T153500
DTEND;TZID=America/New_York:20151026T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27216
SUMMARY:Dynamical systems seminar - Systolic inequalities in symplectic geo
metry
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Systolic inequalitie
s in symplectic geometry\nSpeaker: Umberto Hryniewicz\, Institute of Mathe
matics\, University of Rio de Janeiro\, Brazil\nAbstract: Given a Reeb flo
w on a closed 3-manifold\, how small is the smallest period among closed t
rajectories? A conjecture of Viterbo would imply that for convex energy le
vels the smallest period is not larger than square root of contact volume.
This question contains as a special case the following one: Given a close
d riemannian surface\, how short is the shortest non-constant closed geode
sic? A conjecture of Babenko-Balacheff states that for metrics on the 2-sp
here near the round one\, the length of the shortest closed geodesic is no
t larger than square root of pi times total area. In this talk I will disc
uss recent results concerning both conjectures: we confirm the Babenko-Bal
acheff conjecture (even for metrics not so close to the round one)\, and o
btain sharp systolic inequalities for convex energy levels near the standa
rd 3-sphere. This is joint work with Abbondandolo\, Bramham and Salomão.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151102T153500
DTEND;TZID=America/New_York:20151102T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27217
SUMMARY:Dynamical systems seminar - Feral pseudoholomorhpic curves and mini
mal subsets
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Feral pseudoholomorh
pic curves and minimal subsets\nSpeaker: Joel Fish\, University of Massach
usetts\, Boston\nAbstract: I will discuss some current joint work with Hel
mut Hofer\, in which we\ndefine and establish properties of a new class of
pseudoholomorhic\ncurves (feral J-curves) to study certain divergence fre
e flows in\ndimension three. In particular\, we show that if H is a smooth
\, proper\,\nHamiltonian in R^4\, then no energy level of H is minimal. T
hat is\, the\nflow of the associated Hamiltonian vector field has a trajec
tory which\nis not dense.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151109T153500
DTEND;TZID=America/New_York:20151109T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27218
SUMMARY:Dynamical systems seminar - On a conjecture of Charles Tresser abou
t surfaces diffeomorphisms in the boundary of chaos
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: On a conjecture of C
harles Tresser about surfaces diffeomorphisms in the boundary of chaos\nSp
eaker: Enrique Pujals\, Instituto de Matematica Pura e Aplicada\, Brazil\n
Abstract: Inspired by his initial studies about the boundary of chaos for
\none-dimensional interval endomorphisms\, C. Tresser conjectured that\ni
n the space of C^k orientation preserving embedding of the two disk which
are area\ncontracting\, maps which belongs to the boundary of positive\nto
pological entropy exhibit a period doubling cascade.\n\nIn a joint work wi
th S. Crovisier and C. Tresser we prove such\nconjecture assuming also tha
t the embedding are in the boundary of\nzero-entropy systems and are "str
ongly dissipative". We will relate\nour results with the problem of (topol
ogical) renormalization for\ntwo-dimensional diffeormorphisms and Sharkovs
kii type results.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151116T153500
DTEND;TZID=America/New_York:20151116T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27219
SUMMARY:Dynamical systems seminar - Asymptotic shapes for ergodic families
of metrics on nilpotent groups
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Asymptotic shapes fo
r ergodic families of metrics on nilpotent groups\nSpeaker: Alex Furman\,
University of Illinois at Chicago\nAbstract: In this joint work with Micha
el Cantrell\, we study three closely\nrelated problems:\nGiven a finitely
generated\, virtually nilpotent group $G$\n(i) describe the asymptotic con
e for an equivariant ergodic family of\ninner metrics on $G$ (this is a "r
andomized version" of Pansu's\ntheorem)\;\n(ii) describe the limit shapes
for First Passage Percolation for\ngeneral (not necessarily independent) e
rgodic process on edges of a\nCayley graph of $G$\;\n(iii) establish a sub
-additive ergodic theorem over a general ergodic G-action.\nThe limiting o
bjects are given in terms of a Carnot-Caratheodory\nmetric on the graded n
ilpotent group associated to the Mal'cev\ncompletion of $G$.\nIn the proof
one needs to prove an Ergodic theorem along "polygonal\npaths" of the for
m $T_k^n\\cdots T_2^nT_1^n$ for elements\n$T_1\,\\dots\,T_k$ in $G$.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151123T153500
DTEND;TZID=America/New_York:20151123T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27220
SUMMARY:Dynamical systems seminar - Thanksgiving break
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Thanksgiving break\n
Speaker: NO SEMINAR
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151130T153500
DTEND;TZID=America/New_York:20151130T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27221
SUMMARY:Dynamical systems seminar - Cutting sequences and dual relationship
s for Bouw-Möller surfaces
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Cutting sequences an
d dual relationships for Bouw-Möller surfaces\nSpeaker: Diana Davis\, Nor
thwestern University\nAbstract: Bouw-Möller surfaces are flat surfaces ma
de of polygons. Each one has an associated directed graph\, called a "tran
sition diagram\," that says something about how a geodesic can cut across
its edges. These transition diagrams have a beautiful structure\, which co
mes from a "dual" property relating pairs of surfaces. I will show how thi
s works\, with lots of pictures. (Joint work with Corinna Ulcigrai and Ire
ne Pasquinelli)
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151207T153500
DTEND;TZID=America/New_York:20151207T163500
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=27222
SUMMARY:Dynamical systems seminar - Flexibility of topological and metric e
ntropies for surfaces of negative curvature.
DESCRIPTION:Seminar: Dynamical systems seminar\nTitle: Flexibility of topol
ogical and metric entropies for surfaces of negative curvature.\nSpeaker:
Alena Erchenko\, Penn State\nAbstract: We consider a smooth closed surface
$M$ of fixed genus $\\geqslant 2$ and fixed volume with a Riemannian metr
ic $g$ of negative curvature. A. Katok has shown that the topological entr
opy of geodesic flow for $g$ is greater than or equal to the topological e
ntropy for the metric of constant negative curvature on $M$ which is great
er than or equal to the metric entropy with respect to the Liouville measu
re of geodesic flow for $g$. Equality holds only in the case of constant n
egative curvature. It turns out that this is the only restriction on pairs
of values of topological and metric entropies. We will discuss several ex
amples with particular distributions of curvature.
END:VEVENT
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