BEGIN:VCALENDAR
PRODID:-//PSU Mathematics Department//Seminar iCalendar Generator//EN
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CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:GAP 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
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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150120T143000
DTEND;TZID=America/New_York:20150120T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24738
SUMMARY:GAP Seminar - Polyfolds and Fredholm theory
DESCRIPTION:Seminar: GAP Seminar\nTitle: Polyfolds and Fredholm theory\nSpe
aker: Kris Wysocki\, Penn State University\nAbstract: One of the main tool
s in symplectic topology is the study of moduli spaces of pseudo-holomorph
ic maps defined on\, perhaps punctured\,\nRiemann surfaces with images in
symplectic manifolds\, symplectizations\,\nor symplectic cobordisms. In g
eneral\, these moduli spaces do not permit a satisfactory classical descr
iption in view of non-compactness phenomena. \nIn the talk I will give a s
hort introduction to the polyfold theory which provides an analytical fram
ework to deal with these issues.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150127T143000
DTEND;TZID=America/New_York:20150127T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24740
SUMMARY:GAP Seminar - Symmetry and Geometric Structure for the Worpitzky id
entity
DESCRIPTION:Seminar: GAP Seminar\nTitle: Symmetry and Geometric Structure f
or the Worpitzky identity\nSpeaker: Nick Early\, Penn State University\nAb
stract: The classical Worpitzky identity for the symmetric group $S_n$ dec
omposes a cubical lattice into $n!$ simplices of different sizes\, each wi
th a multiplicity counted by the number of permutations of $n$ with a fixe
d number of descents. It is well-known in combinatorics that the Eulerian
numbers can be represented as volumes of suitably normalized hypersimplic
es. We show how the Worpitzky identity encodes localization data for a sy
stem of simplicial polyhedral cones which emerge from the $A_n$ simple roo
t system\, and becomes now an isomorphism between two new graded\, simplic
ial symmetric group representations.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150203T143000
DTEND;TZID=America/New_York:20150203T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24742
SUMMARY:GAP Seminar - Time and almost-positive linear functions on algebras
DESCRIPTION:Seminar: GAP Seminar\nTitle: Time and almost-positive linear fu
nctions on algebras\nSpeaker: Martin Bojowald\, Penn State University\nAbs
tract: One of the apparent incompatibilities between quantum mechanics and
general relativity is the treatment of time as an eternal parameter in th
e former and as a local coordinate in the latter theory. I will describe r
ecent ideas which try to overcome this problem by taking the algebraic vie
w of quantum states as linear functionals on the algebra of observables. A
time variable may then be taken as an element of the algebra in order to
describe evolution locally\, while transformations between different time
choices must be made for long-term evolution resembling a manifold picture
. Algebraic states that include time in this sense violate the usual posit
ivity condition\, but still obey a weaker form of almost-positive linear f
unctionals.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150210T143000
DTEND;TZID=America/New_York:20150210T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24744
SUMMARY:GAP Seminar - Concrete Representations of GL(n)
DESCRIPTION:Seminar: GAP Seminar\nTitle: Concrete Representations of GL(n)
\nSpeaker: Adrian Ocneanu\, Penn State\nAbstract: We present a new view of
the Gelfand Tsetlin approach to representations of GL(n)\nand their inter
twiners.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150217T143000
DTEND;TZID=America/New_York:20150217T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24746
SUMMARY:GAP Seminar - Gauge theories and Lie groupoids
DESCRIPTION:Seminar: GAP Seminar\nTitle: Gauge theories and Lie groupoids\n
Speaker: Thomas Strobl\, University of Lyon I\nAbstract: After briefly rev
iewing Lie groupoids and Lie algebroids\, which are generalizations of Lie
groups and their Lie algebras\, we first explain why in the (standard) co
nstruction of gauge theories only Lie groups seem to be admissible. While
the Poisson sigma model already provides an example of a topological field
theory based on a target Lie algebroid symmetry\, we show that even the g
auging of the standard sigma model\, governed by a Riemannian manifold on
the target\, can lead naturally to Lie algebroids/groupoids\, an option ig
nored up to now.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150224T143000
DTEND;TZID=America/New_York:20150224T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24748
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA\nAbstract Link: http://
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150303T143000
DTEND;TZID=America/New_York:20150303T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24750
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150310T143000
DTEND;TZID=America/New_York:20150310T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24752
SUMMARY:GAP Seminar - Spring break
DESCRIPTION:Seminar: GAP Seminar\nTitle: Spring break\nSpeaker: Spring brea
k
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150317T143000
DTEND;TZID=America/New_York:20150317T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24754
SUMMARY:GAP Seminar - Symplectic Mackey Theory
DESCRIPTION:Seminar: GAP Seminar\nTitle: Symplectic Mackey Theory\nSpeaker:
Francois Ziegler\, Georgia Southern University\nAbstract: When a Lie grou
p G has a closed normal subgroup N\, the “Mackey Machine” breaks down
the classification of its irreducible representations into two smaller pro
blems:\n\na) find the irreducible representations of N\;\nb) find the irre
ducible projective representations of certain subgroups of G/N.\n\nThe des
ired classification often follows inductively. \nKey parts of this machine
are\n\n1) the “inducing construction” (building representations of G
out of those of its subgroups)\;\n2) the “imprimitivity theorem” (char
acterizing the range of the inducing construction)\;\n3) a “tensoring”
construction (combining objects of types a) and b) above).\n\nMany years
ago Kazhdan\, Kostant and Sternberg defined the notion of inducing a hamil
tonian action from a Lie subgroup\, thus introducing a purely symplectic g
eometrical analog of 1)\; and the question arose whether analogs of 2) and
3) could be found and built into an effective “symplectic Mackey Machin
e”. In this talk I will describe a complete solution to this problem\, o
btained recently.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150323T143000
DTEND;TZID=America/New_York:20150323T152000
LOCATION:MB216
URL:http://www.math.psu.edu/seminars/meeting.php?id=27880
SUMMARY:GAP Seminar - Complete integrability from Poisson Nijenhuis structu
res on compact hermitian symmetric spaces
DESCRIPTION:Seminar: GAP Seminar\nTitle: Complete integrability from Poisso
n Nijenhuis structures on compact hermitian symmetric spaces\nSpeaker: Fra
ncesco Bonechi\, Istituto Nazionale Fisica Nucleare - Firenze\nAbstract: T
he so called Bruhat-Poisson structure is compatible with the Kostant-Kiril
lov-Souriau bracket when considered on compact hermitian symmetric spaces.
This property allows the definition of a Poisson Nijenhuis structure. We
study the spectrum of the Nijenhuis tensor\, which proves to be non degene
rate and defines a completely integrable model. On the Grassmannians this
is the well known Gelfand-Cetlin model. By construction these models have
a bihamiltonian description\,\ni.e. the hamiltonians are in involution wit
h respect to both Poisson structures. In this talk I will review the basic
facts needed for this analysis\, namely the construction of integrable mo
dels from collective hamiltonians (Thimm method) and Poisson vector bundle
s. The point of view mainly focuses on the geometry of the Bruhat-Poisson
structures\, in particular on its symplectic groupoid.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150324T143000
DTEND;TZID=America/New_York:20150324T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24756
SUMMARY:GAP Seminar - Gravity in three dimensions: physical foundations
DESCRIPTION:Seminar: GAP Seminar\nTitle: Gravity in three dimensions: physi
cal foundations\nSpeaker: Marc Geiller\, Penn State\nAbstract: The year 20
15 marks the centennial anniversary of the birth of Einstein's theory of g
eneral relativity\, which is so far the most successful and experimentally
tested description of the gravitational interaction. Although the physica
l spacetime around us is four-dimensional\, general relativity\, because o
f its geometrical nature\, can also be formulated in three spacetime dimen
sions. There it exhibits special mathematical structure\, and can be studi
ed in exactly soluble ways. The goal of this series of lectures is to pres
ent some aspects of the rich interplay that exists between mathematics and
physics within the context of three-dimensional gravity.\n\nPart 1: Physi
cal foundations\nPart 2: Mathematical formulations\nPart 3: Quantization v
ia loop groups\nPart 4: Path integral quantization and topological invaria
nts
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150331T143000
DTEND;TZID=America/New_York:20150331T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24758
SUMMARY:GAP Seminar - Gravity in three dimensions: mathematical foundations
DESCRIPTION:Seminar: GAP Seminar\nTitle: Gravity in three dimensions: mathe
matical foundations\nSpeaker: Marc Geiller\, Penn State\nAbstract: The yea
r 2015 marks the centennial anniversary of the birth of Einstein's theory
of general relativity\, which is so far the most successful and experiment
ally tested description of the gravitational interaction. Although the phy
sical spacetime around us is four-dimensional\, general relativity\, becau
se of its geometrical nature\, can also be formulated in three spacetime d
imensions. There it exhibits special mathematical structure\, and can be s
tudied in exactly soluble ways. The goal of this series of lectures is to
present some aspects of the rich interplay that exists between mathematics
and physics within the context of three-dimensional gravity.\n\nPart 1: P
hysical foundations\nPart 2: Mathematical formulations\nPart 3: Quantizati
on via loop groups\nPart 4: Path integral quantization and topological inv
ariants
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150407T143000
DTEND;TZID=America/New_York:20150407T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24760
SUMMARY:GAP Seminar - Gravity in three dimensions: path integral quantizati
on and topological invariants
DESCRIPTION:Seminar: GAP Seminar\nTitle: Gravity in three dimensions: path
integral quantization and topological invariants\nSpeaker: Marc Geiller\,
Penn State\nAbstract: The year 2015 marks the centennial anniversary of th
e birth of Einstein's theory of general relativity\, which is so far the m
ost successful and experimentally tested description of the gravitational
interaction. Although the physical spacetime around us is four-dimensional
\, general relativity\, because of its geometrical nature\, can also be fo
rmulated in three spacetime dimensions. There it exhibits special mathemat
ical structure\, and can be studied in exactly soluble ways. The goal of t
his series of lectures is to present some aspects of the rich interplay th
at exists between mathematics and physics within the context of three-dime
nsional gravity.\n\nPart 1: Physical foundations\nPart 2: Mathematical for
mulations\nPart 3: Quantization via loop groups\nPart 4: Path integral qua
ntization and topological invariants
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150414T143000
DTEND;TZID=America/New_York:20150414T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24762
SUMMARY:GAP Seminar - Split octonions and the rolling ball
DESCRIPTION:Seminar: GAP Seminar\nTitle: Split octonions and the rolling ba
ll\nSpeaker: John Baez\, UC Riverside\nAbstract: Understanding exceptional
Lie groups as the symmetry groups of more familiar objects is a fascinati
ng challenge. The compact form of the smallest exceptional Lie group\, G2
\, is the symmetry group of an 8-dimensional nonassociative algebra called
the octonions. However\, another form of this group arises as symmetries
of a simple problem in classical mechanics! The space of configurations of
a ball rolling on another ball without slipping or twisting defines a man
ifold where the tangent space of each point is equipped with a 2-dimension
al subspace describing the allowed infinitesimal motions. Under certain sp
ecial conditions\, the split real form of G2 acts as symmetries. We can un
derstand this using the quaternions together with an 8-dimensional algebra
called the 'split octonions'. The rolling ball picture makes the geometry
associated to G2 quite vivid. This is joint work with James Dolan and Joh
n Huerta.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150421T143000
DTEND;TZID=America/New_York:20150421T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24764
SUMMARY:GAP Seminar - Pythagorean (in)equalities in noncommutative geometry
DESCRIPTION:Seminar: GAP Seminar\nTitle: Pythagorean (in)equalities in nonc
ommutative geometry\nSpeaker: Francesco D'Andrea\, University of Naples\n
Abstract: In many different fields\, from transport theory to quantum info
rmation\, one is lead to study metrics on the state space S of a C*-algebr
a. A "geometric" way to define a distance on S is by means of a spectral t
riple. I will discuss the relation between Connes' distance and the produc
t metric for a product of two spectral triples. I will present some (optim
al) inequalities that are satisfied by arbitrary states and spectral tripl
es\, and a criterion that can be applied to some classes of examples to in
vestigate whether Connes' distance and the product metric coincide.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150428T143000
DTEND;TZID=America/New_York:20150428T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24766
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA\nSpeaker: Stephane Korvers\, U
niversity of Luxembourg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150505T143000
DTEND;TZID=America/New_York:20150505T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=24767
SUMMARY:GAP Seminar - Irregular Riemann-Hilbert correspondence and Alekseev
-Meinrenken dynamical r-matrix
DESCRIPTION:Seminar: GAP Seminar\nTitle: Irregular Riemann-Hilbert correspo
ndence and Alekseev-Meinrenken dynamical r-matrix\nSpeaker: Xiaomeng Xu\,
University of Geneva\nAbstract: In 2004\, Enriquez-Etingof-Marshall sugges
ted a new approach to the Ginzburg-Weinstein linearization theorem. This a
pproach is based on solving a system of PDEs for a gauge transformation be
tween the standard classical r-matrix and the Alekseev-Meinrenken dynamica
l r-matrix. In the talk\, we explain that this gauge transformation can be
constructed as a monodromy (connection matrix) for a certain irregular Ri
emann-Hilbert problem. Geometrically\, this leads to a symplectic neighbor
hood version of the Ginzburg-Weinstein linearization theorem. Our construc
tion is based on earlier works by Boalch. As an application\, we give a ne
w description of the Lu-Weinstein symplectic double.
END:VEVENT
END:VCALENDAR