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
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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:20150901T143000
DTEND;TZID=America/New_York:20150901T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27016
SUMMARY:GAP Seminar - Yang-Baxter and reflection equations: unifying struct
ures behind quantum and classical integrable systems
DESCRIPTION:Seminar: GAP Seminar\nTitle: Yang-Baxter and reflection equatio
ns: unifying structures behind quantum and classical integrable systems\nS
peaker: Vincent Caudrelier\, City University of London\nAbstract: The Yang
-Baxter equation (YBE) is central in the theory of quantum integrable syst
ems. For decades\, together with its companion for problems with boundarie
s (the quantum reflection equation)\, it has been studied and used in the
quantum realm\, leading to the area of quantum groups. But it was suggeste
d by Drinfeld in 1990 that the general study of the so-called «set-theore
tical YBE » is also important. This can be understood as the problem of f
inding nonlinear representations of the braid group on arbitrary sets. It
turns out that classical integrable PDEs provide a means to construct cert
ain types of such representations\, called Yang-Baxter maps\, by looking a
t soliton collisions. I will use the vector nonlinear Schrödinger (NLS) e
quation as the main example to illustrate the idea. It has its origin in t
he physics of wave phenomena in fluid dynamics\, nonlinear optics\, plasma
physics or quantum cold gases. After reviewing this\, I will show how the
new concept of set-theoretical reflection equation naturally emerges by s
tudying solitons in integrable PDEs with a boundary. As before\, the probl
em of finding solutions to this equation can be understood as the question
of finding nonlinear representations of the finite Coxeter group of type
BCn. I will show how to construct such representations using solitons.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150908T143000
DTEND;TZID=America/New_York:20150908T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27020
SUMMARY:GAP Seminar - Geometry of broken Lefschetz fibrations
DESCRIPTION:Seminar: GAP Seminar\nTitle: Geometry of broken Lefschetz fibra
tions\nSpeaker: Ramon Vera\, Penn State\nAbstract: In this talk\, we will
discuss two geometric structures that are naturally associated to broken
Lefschetz fibrations: near-symplectic forms and singular Poisson structure
s. Broken Lefschetz fibrations\, or bLfs\, were introduced by Auroux\, Do
naldson\, and Katzarkov as mappings from a 4-manifold to the 2-sphere with
two types of singularities. The natural geometric structure of these map
pings is a near-symplectic form. This connects to an idea of Taubes of stu
dying near-symplectic structures on 4-manifolds as a generalization of sym
plectic topology. Since then\, these fibrations have found applications in
low-dimensional topology and symplectic geometry. One reason is that ever
y 4-manifold admits a bLf. After introducing bLfs\, we will describe near-
symplectic forms and present the generalization in higher dimensions. Usin
g bLfs\, we will also see a link to Poisson geometry. Any homotopy class
of maps from a 4-manifold to the 2-sphere admits a singular Poisson struct
ure of rank 2\, whose foliation is compatible with the fibres of a bLf.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150915T143000
DTEND;TZID=America/New_York:20150915T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27024
SUMMARY:GAP Seminar - Generalized contact bundles
DESCRIPTION:Seminar: GAP Seminar\nTitle: Generalized contact bundles\nSpeak
er: Aissa Wade\, Penn State\nAbstract: Generalized contact bundles are nat
ural extensions of contact structures. They also can be viewed as odd-dime
nsional analogues of generalized complex structures. One of their apparent
advantages is that they incorporate both coorientable and non-coorientabl
e contact structures. A fundamental fact is that there is always a Jacobi
structure underlying any given generalized contact bundle. After describin
g multiplicative Atiyah forms on Lie groupoids\, I will give a complete ch
aracterization of generalized contact bundles having a non-degenerate asso
ciated Jacobi structure. I will then explain aspects of generalized contac
t bundle from the point of view of Lie algebroids and the Lie groupoids. T
his is a joint work with Luca Vitagliano.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150922T143000
DTEND;TZID=America/New_York:20150922T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27028
SUMMARY:GAP Seminar - The limit operator symbol
DESCRIPTION:Seminar: GAP Seminar\nTitle: The limit operator symbol\nSpeaker
: John Roe\, Penn State\nAbstract: The familiar symbol of a pseudodifferen
tial operator is a\nmatrix-valued function which has the property that\, i
f the symbol is\ninvertible\, the operator is Fredholm. In this talk I wi
ll discuss the\nindex theory of "band dominated" operators which leads to
an abstract\nversion of this symbol calculus (reducing to the pseudodiffer
ential\nversion in a very special case). For many years this theory was\n
incomplete\; it was only recently completed by Lindner-Seidel (in the free
\nabelian case) and then Spakula-Willett in general. I'll explain what t
he\nquestion was\, how it was resolved\, and what might happen next.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20150929T143000
DTEND;TZID=America/New_York:20150929T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27032
SUMMARY:GAP Seminar - D-branes and twisted K-homology I
DESCRIPTION:Seminar: GAP Seminar\nTitle: D-branes and twisted K-homology I
\nSpeaker: Paul Baum\, Penn State\nAbstract: K-homology is the dual theory
to K-theory. This talk will first review ordinary (i.e. not twisted) K-ho
mologyand will then introduce twisted K-homology via a definition which us
es functional analysis a la Kasparov. How can twisted K-homology be define
d geometrically? The talk will conclude with the Baum-Carey-Wang geometric
definition of twisted K-homology and how this relates to the Kasparov def
inition and to the D-branes of string theory.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151006T143000
DTEND;TZID=America/New_York:20151006T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27035
SUMMARY:GAP Seminar - D-branes and twisted K-homology II
DESCRIPTION:Seminar: GAP Seminar\nTitle: D-branes and twisted K-homology II
\nSpeaker: Paul Baum\, Penn State\nAbstract: K-homology is the dual theory
to K-theory. This talk will first review ordinary (i.e. not twisted) K-ho
mologyand will then introduce twisted K-homology via a definition which us
es functional analysis a la Kasparov. How can twisted K-homology be define
d geometrically? The talk will conclude with the Baum-Carey-Wang geometric
definition of twisted K-homology and how this relates to the Kasparov def
inition and to the D-branes of string theory.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151013T143000
DTEND;TZID=America/New_York:20151013T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27039
SUMMARY:GAP Seminar - Immmersions of the circle in the sphere and in higher
Riemann surfaces
DESCRIPTION:Seminar: GAP Seminar\nTitle: Immmersions of the circle in the s
phere and in higher Riemann surfaces\nSpeaker: Robert Coquereaux\, Centre
de Physique Théorique (CPT)\nAbstract: We encode circle immersions with
n crossings in terms of orbits of the centraliser of a special element of
the symmetric groups S(2n) or S(4n) acting by conjugation on particular su
bsets\, or in terms of appropriate double cosets. The details depend on th
e various orientability hypothesis made on the source (the circle) and on
the target (a surface of genus g)\, and also on a possible constraint of b
i-colariability that one can furthermore impose. \nWe count and tabulate n
on-equivalent images of spherical immersions up to 10 crossings therefore
recovering and extending results by Arnold (5 crossings) and followers (7
crossings)\, we also obtain the corresponding classifications for genus hi
gher than 0. In the latter case we introduce the notion of bicolourability
and determine the first terms (up to 9 crossings) of the corresponding se
quences. \nThis presentation summarizes recent work done in collaboration
with with J.-B. Zuber.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151020T143000
DTEND;TZID=America/New_York:20151020T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27043
SUMMARY:GAP Seminar - Associating quantum vertex algebras to quantum affine
algebras
DESCRIPTION:Seminar: GAP Seminar\nTitle: Associating quantum vertex algebra
s to quantum affine algebras\nSpeaker: Haisheng Li\, Rutgers-Camden\nAbstr
act: n this talk\, I will report on the progress in a program to\nassociat
e quantum vertex algebras to quantum affine algebras.\nPreviously\, motiva
ted by Etingof-Kazhdan's work\,\nwe developed a theory of (weak) quantum v
ertex algebras and their\nmodules. Here\, I will explain how one can\nasso
ciate weak quantum vertex algebras to quantum affine algebras\nthrough wha
t are called phi-coordinated modules.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151027T143000
DTEND;TZID=America/New_York:20151027T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27047
SUMMARY:GAP Seminar - Strong Bogomolov inequalities and ample divisors on m
oduli spaces of sheaves
DESCRIPTION:Seminar: GAP Seminar\nTitle: Strong Bogomolov inequalities and
ample divisors on moduli spaces of sheaves\nSpeaker: Jack Huizenga\, Penn
State\nAbstract: The existence problem for semistable sheaves on a surface
seeks to classify the possible numerical invariants of a semistable sheaf
. In other words\, for what numerical invariants is the moduli space of se
mistable sheaves nonempty? The classical Bogomolov inequality says that an
y semistable sheaf has nonnegative discriminant\, so this is one restricti
on on the possible numerical invariants. Strong Bogomolov inequalities ar
e refinements which further restrict the possible invariants\; they often
have interesting number-theoretic or combinatorial structure\, related to
the geometry of rigid bundles. In this talk I will explain a close relatio
nship between such inequalities and the computation of cones of ample divi
sors on moduli spaces of sheaves with large discriminant. This is joint w
ork with Izzet Coskun.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151103T143000
DTEND;TZID=America/New_York:20151103T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27051
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151110T143000
DTEND;TZID=America/New_York:20151110T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27055
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151117T143000
DTEND;TZID=America/New_York:20151117T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27059
SUMMARY:GAP Seminar - Algebraic Families of Harish-Chandra pairs and their
modules I
DESCRIPTION:Seminar: GAP Seminar\nTitle: Algebraic Families of Harish-Chand
ra pairs and their modules I\nSpeaker: Eyal Subag\, Penn State\nAbstract:
In my talk I will try to convince you that Lie groups come in natural alge
braic families. A construction of such families that relates different rea
l forms of GL(n\,C)\, and SL(n\,C) will be given. Moreover\, we shall see
that we can naturally associate families of Harish-Chandra pairs to these
families of groups. For the family that goes through SU(2)\, SU(1\,1)\, a
nd their Cartan motion group\, a classification of generically irreducible
Harish Chandra modules will be given. As an application\, a formulation o
f the Mackey bijection between the duals of SU(1\,1) and its Cartan motio
n group in terms of families of Harish Chandra modules will be presented.
The talk is based on a joint work with Joseph Bernstein and Nigel Higson.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151124T143000
DTEND;TZID=America/New_York:20151124T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27063
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA\nSpeaker: Thanksgiving
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151201T143000
DTEND;TZID=America/New_York:20151201T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27067
SUMMARY:GAP Seminar - Algebraic Families of Harish-Chandra pairs and their
modules II
DESCRIPTION:Seminar: GAP Seminar\nTitle: Algebraic Families of Harish-Chand
ra pairs and their modules II\nSpeaker: Eyal Subag\, Penn State\nAbstract:
In my talk I will try to convince you that Lie groups come in natural alg
ebraic families. A construction of such families that relates different re
al forms of GL(n\,C)\, and SL(n\,C) will be given. Moreover\, we shall see
that we can naturally associate families of Harish-Chandra pairs to these
families of groups. For the family that goes through SU(2)\, SU(1\,1)\, a
nd their Cartan motion group\, a classification of generically irreducible
Harish Chandra modules will be given. As an application\, a formulation o
f the Mackey bijection between the duals of SU(1\,1) and its Cartan motion
group in terms of families of Harish Chandra modules will be presented. T
he talk is based on a joint work with Joseph Bernstein and Nigel Higson.
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151208T143000
DTEND;TZID=America/New_York:20151208T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27071
SUMMARY:GAP Seminar - TBA
DESCRIPTION:Seminar: GAP Seminar\nTitle: TBA\nSpeaker: Zvi Rosen\, Penn Sta
te
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20151215T143000
DTEND;TZID=America/New_York:20151215T153000
LOCATION:MB106
URL:http://www.math.psu.edu/seminars/meeting.php?id=27075
SUMMARY:GAP Seminar - Localization and the canonical commutation relations
DESCRIPTION:Seminar: GAP Seminar\nTitle: Localization and the canonical com
mutation relations\nSpeaker: Patrick Moylan\, Penn State\nAbstract Link: h
ttp://www.personal.psu.edu/ndh2/MoylanGapAbstract.pdf
END:VEVENT
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