BEGIN:VCALENDAR
PRODID:-//PSU Mathematics Department//Seminar iCalendar Generator//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Noncommutative Geometry 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:20150129T143000
DTEND;TZID=America/New_York:20150129T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25484
SUMMARY:Noncommutative Geometry Seminar - Oka principle: commutative and n
oncommutative. I
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Oka principle:
commutative and noncommutative. I\nSpeaker: Nigel Higson\, Penn State\nA
bstract: The original Oka principle asserts that smooth vector bundles on
closed\, complex submanifolds of complex affine space admit unique holomor
phic structures. It has obvious implications for K-theory\, and\, through
them\, potential applications to noncommutative geometry\, especially to t
he Baum-Connes conjecture. I'll discuss the original result (due to Oka a
nd Grauert)\, and then actual as well as potential extensions to the nonco
mmutative context.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150205T143000
DTEND;TZID=America/New_York:20150205T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25485
SUMMARY:Noncommutative Geometry Seminar - Odd-dimensional multi-pullback qu
antum spheres
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Odd-dimensiona
l multi-pullback quantum spheres\nSpeaker: Piotr Hajac\, Polish Academy of
Sciences\nAbstract: We construct a noncommutative deformation of odd-dime
nsional spheres that preserves the natural partition of the (2n+1)-dimensi
onal sphere into (n+1)-many solid tori. This generalizes the case n = 1 re
ferred to as the Heegaard quantum sphere. Our odd-dimensional quantum sphe
re C*-algebras are given as multi-pullback C*-algebras. We prove that they
are isomorphic to the universal C*-algebras generated by certain isometri
es\, and use this result to compute the K-groups of our odd-dimensional qu
antum spheres. Furthermore\, we prove that the fixed-point subalgebras und
er the diagonal U(1)-action on our quantum sphere C*-algebras yield the in
dependently defined C*-algebras of the quantum complex projective spaces c
onstructed from the Toeplitz cubes. Then\, by constructing a strong connec
tion\, we show that this U(1)-action is free. This leads to the main resul
t stating that the noncommutative line bundles over the quantum complex pr
ojective spaces that are associated to this action via non-trivial represe
ntations of U(1) are not stably trivial. (Based on joint work with D. Pask
\, A. Sims and B. Zieliński.)
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150212T143000
DTEND;TZID=America/New_York:20150212T153000
LOCATION:MB114
URL:http://www.math.psu.edu/seminars/meeting.php?id=25486
SUMMARY:Noncommutative Geometry Seminar - Classifications of symmetry prote
cted topological phases in interacting boson/fermion systems
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Classification
s of symmetry protected topological phases in interacting boson/fermion sy
stems\nSpeaker: Zhengcheng Gu\, Perimeter Institute\nAbstract: Symmetry pr
otected topological (SPT) states are bulk gapped states with gapless edge
excitations protected by certain symmetries. The SPT phases in free fermio
n systems\, like topological insulators\, can be classified by the K-theor
y. However\, it is not known what SPT phases exist in general interacting
systems. In this talk\, I will first present a systematic way to construct
SPT phases in interacting boson systems\, which allows us to identify man
y new SPT phases\, including three bosonic versions of topological insulat
ors in three dimensions and one in two dimensions protected by particle nu
mber conservation and time reversal symmetry. Just like group theory allow
s us to construct 230 crystal structures in 3D\, we find that group cohomo
logy theory allows us to construct different interacting bosonic SPT phase
s in any dimensions and for any symmetry groups. In particular\, I am goin
g to show how topological terms in the path integral description of the sy
stem can be constructed from nontrivial group cohomology classes\, giving
rise to exactly soluble Hamiltonians\, explicit ground state wavefunction.
If time is allowed\, I will discuss the generalization of the classifying
scheme for interacting fermion/electron systems and propose a new mathema
tical framework – group supercohomology theory\, which predicts a novel
fermionic SPT phase that can neither be realized in free fermion systems n
or in interacting boson systems.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150219T143000
DTEND;TZID=America/New_York:20150219T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25487
SUMMARY:Noncommutative Geometry Seminar - Oka principle: commutative and no
ncommutative. II
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Oka principle:
commutative and noncommutative. II\nSpeaker: Nigel Higson\, Penn State\nA
bstract: The original Oka principle asserts that smooth vector bundles on
closed\, complex submanifolds of complex affine space admit unique holomor
phic structures. It has obvious implications for K-theory\, and\, through
them\, potential applications to noncommutative geometry\, especially to t
he Baum-Connes conjecture. I'll discuss the original result (due to Oka an
d Grauert)\, and then actual as well as potential extensions to the noncom
mutative context.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150226T143000
DTEND;TZID=America/New_York:20150226T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25488
SUMMARY:Noncommutative Geometry Seminar - Oka principle: commutative and no
ncommutative. III
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Oka principle:
commutative and noncommutative. III\nSpeaker: Nigel Higson\, Penn State\n
Abstract: The original Oka principle asserts that smooth vector bundles on
closed\, complex submanifolds of complex affine space admit unique holomo
rphic structures. It has obvious implications for K-theory\, and\, through
them\, potential applications to noncommutative geometry\, especially to
the Baum-Connes conjecture. I'll discuss the original result (due to Oka a
nd Grauert)\, and then actual as well as potential extensions to the nonco
mmutative context.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150305T143000
DTEND;TZID=America/New_York:20150305T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25489
SUMMARY:Noncommutative Geometry Seminar - Intermediate C*-norms
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Intermediate C
*-norms\nSpeaker: Matthew Wiersma\, University of Waterloo\nAbstract: It i
s known that C*-algebras admit unique C*-norms\, but this is not true in g
eneral for dense *-subalgebras of C*-algebras. For example\, if G is a dis
crete group\, then its group ring algebra may admit more than one C*-norm.
Similarly\, the algebraic tensor product of two C*-algebras may admit mul
tiple C*-norms. Each of these examples admits two canonical C*-norms. Duri
ng this talk\, we will investigate C*-norms which fall between these canon
ical constructions.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150312T143000
DTEND;TZID=America/New_York:20150312T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25490
SUMMARY:Noncommutative Geometry Seminar - No seminar
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: No seminar\nSp
eaker: Spring Break
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150319T143000
DTEND;TZID=America/New_York:20150319T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25491
SUMMARY:Noncommutative Geometry Seminar - Higher signatures on Witt spaces
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Higher signatu
res on Witt spaces\nSpeaker: Zhizhang Xie\, Texas A&M\nAbstract: The signa
ture is a fundamental homotopy invariant for topological manifolds. Howeve
r\, for spaces with singularities\, this usual notion of signature ceases
to exist\, since\, in general\, spaces with singularities fail the usual P
oincaré duality. A generalized Poincaré duality theorem for spaces with
singularities was proven by Goresky and MacPherson using intersection homo
logy. The classical signature was then extended to Witt spaces by Siegel u
sing this generalized Poincaré duality. Witt spaces are a natural class o
f spaces with singularities. For example\, all complex algebraic varieties
are Witt spaces. In this talk\, I will describe a combinatorial approach
to higher signatures of Witt spaces\, using methods of noncommutative geom
etry. This is based on joint work with Nigel Higson.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150326T143000
DTEND;TZID=America/New_York:20150326T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25492
SUMMARY:Noncommutative Geometry Seminar - Gravity in three dimensions: disc
ussion
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Gravity in thr
ee dimensions: discussion\nSpeaker: Nigel Higson\, Penn State
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150402T143000
DTEND;TZID=America/New_York:20150402T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25493
SUMMARY:Noncommutative Geometry Seminar - Gravity in three dimensions: quan
tization via loop groups
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Gravity in thr
ee dimensions: quantization via loop groups\nSpeaker: Marc Geiller\, Penn
State\nAbstract: The year 2015 marks the centennial anniversary of the bir
th of Einstein's theory of general relativity\, which is so far the most s
uccessful and experimentally tested description of the gravitational inter
action. Although the physical spacetime around us is four-dimensional\, ge
neral relativity\, because of its geometrical nature\, can also be formula
ted in three spacetime dimensions. There it exhibits special mathematical
structure\, and can be studied in exactly soluble ways. The goal of this s
eries of lectures is to present some aspects of the rich interplay that ex
ists between mathematics and physics within the context of three-dimension
al gravity.\n\nPart 1: Physical foundations\nPart 2: Mathematical formulat
ions\nPart 3: Quantization via loop groups\nPart 4: Path integral quantiza
tion and topological invariants
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150409T143000
DTEND;TZID=America/New_York:20150409T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25494
SUMMARY:Noncommutative Geometry Seminar - Loop groups and Dirac operators o
n quasi-Hamiltonian G-spaces
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Loop groups an
d Dirac operators on quasi-Hamiltonian G-spaces\nSpeaker: Yanli Song\, Uni
versity of Toronto\nAbstract: A quasi-Hamiltonian G-space is a finite dime
nsional model\, introduced by Alekseev-Malkin-Meinrenken\, for a Hamiltoni
an loop group space. In this talk\, I will discuss some basic properties
of q-Hamiltonian G-spaces\, and construct twisted spinor bundles and twist
ed prequantum bundles on them. Then I will define the Dirac operator on a
q-Hamiltonian G-space\, with index given by a positive energy representati
on of the loop group. This generalizes the quantization of Hamiltonian G-s
paces to quasi-Hamiltonian G-spaces.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150416T143000
DTEND;TZID=America/New_York:20150416T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25495
SUMMARY:Noncommutative Geometry Seminar - Singular foliations and their C*
algebras: calculations. 1.
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Singular folia
tions and their C* algebras: calculations. 1.\nSpeaker: Iakovos Androulida
kis\, University of Athens\nAbstract: Singular foliations are examples of
dynamical systems. They are abundant in many branches of mathematics\, for
instance control theory and Poisson geometry. In fact singular foliations
appear much more often than regular ones. In this series of talks we disc
uss how to deal with the leaf space of such foliations\, including calcula
tions of various examples. Information about this space is encapsulated in
the holonomy groupoid of the foliation and the associated C*-algebra. A t
entative program for these lectures is: (1) singular foliations and bisubm
ersions\, with examples (foliation by the flow of a single vector field\,
by orbits of the SO(3) action\, by orbits of the action of SL(2\,R))\, (b)
calculation of the holonomy groupoid for the above examples\, (c) constr
uction of the foliation C*-algebra\, and (d) K-theory calculation for th
e above examples (the right-hand side of the Baum-Connes assembly map).
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150423T143000
DTEND;TZID=America/New_York:20150423T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25496
SUMMARY:Noncommutative Geometry Seminar - Singular foliations and their C*
algebras: calculations. 2.
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Singular folia
tions and their C* algebras: calculations. 2.\nSpeaker: Iakovos Androulida
kis\, University of Athens\nAbstract: Singular foliations are examples of
dynamical systems. They are abundant in many branches of mathematics\, for
instance control theory and Poisson geometry. In fact singular foliations
appear much more often than regular ones. In this series of talks we disc
uss how to deal with the leaf space of such foliations\, including calcula
tions of various examples. Information about this space is encapsulated in
the holonomy groupoid of the foliation and the associated C*-algebra. A t
entative program for these lectures is: (1) singular foliations and bisubm
ersions\, with examples (foliation by the flow of a single vector field\,
by orbits of the SO(3) action\, by orbits of the action of SL(2\,R))\, (b)
calculation of the holonomy groupoid for the above examples\, (c) constr
uction of the foliation C*-algebra\, and (d) K-theory calculation for th
e above examples (the right-hand side of the Baum-Connes assembly map).
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150430T143000
DTEND;TZID=America/New_York:20150430T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25497
SUMMARY:Noncommutative Geometry Seminar - Singular foliations and their C*
algebras: calculations. 3.
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Singular folia
tions and their C* algebras: calculations. 3.\nSpeaker: Iakovos Androulida
kis\, University of Athens\nAbstract: Singular foliations are examples of
dynamical systems. They are abundant in many branches of mathematics\, for
instance control theory and Poisson geometry. In fact singular foliations
appear much more often than regular ones. In this series of talks we disc
uss how to deal with the leaf space of such foliations\, including calcula
tions of various examples. Information about this space is encapsulated in
the holonomy groupoid of the foliation and the associated C*-algebra. A t
entative program for these lectures is: (1) singular foliations and bisubm
ersions\, with examples (foliation by the flow of a single vector field\,
by orbits of the SO(3) action\, by orbits of the action of SL(2\,R))\, (b)
calculation of the holonomy groupoid for the above examples\, (c) constr
uction of the foliation C*-algebra\, and (d) K-theory calculation for th
e above examples (the right-hand side of the Baum-Connes assembly map).
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150507T143000
DTEND;TZID=America/New_York:20150507T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=25498
SUMMARY:Noncommutative Geometry Seminar - Singular foliations and their C*
algebras: calculations. 4.
DESCRIPTION:Seminar: Noncommutative Geometry Seminar\nTitle: Singular folia
tions and their C* algebras: calculations. 4.\nSpeaker: Iakovos Androulida
ki\, University of Athens\nAbstract: Singular foliations are examples of d
ynamical systems. They are abundant in many branches of mathematics\, for
instance control theory and Poisson geometry. In fact singular foliations
appear much more often than regular ones. In this series of talks we discu
ss how to deal with the leaf space of such foliations\, including calculat
ions of various examples. Information about this space is encapsulated in
the holonomy groupoid of the foliation and the associated C*-algebra. A te
ntative program for these lectures is: (1) singular foliations and bisubme
rsions\, with examples (foliation by the flow of a single vector field\, b
y orbits of the SO(3) action\, by orbits of the action of SL(2\,R))\, (b)
calculation of the holonomy groupoid for the above examples\, (c) constru
ction of the foliation C*-algebra\, and (d) K-theory calculation for the
above examples (the right-hand side of the Baum-Connes assembly map).
END:VEVENT
END:VCALENDAR