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PRODID:researchseminars.org
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BEGIN:VEVENT
SUMMARY:Duncan McCoy (UQAM)
DTSTART;VALUE=DATE-TIME:20200914T190000Z
DTEND;VALUE=DATE-TIME:20200914T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/1
DESCRIPTION:Title: Do
uble slicing for links\nby Duncan McCoy (UQAM) as part of MIT Geometry
and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Powell
DTSTART;VALUE=DATE-TIME:20200928T190000Z
DTEND;VALUE=DATE-TIME:20200928T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/2
DESCRIPTION:Title: St
able diffeomorphism of 4-manifolds\nby Mark Powell as part of MIT Geom
etry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ian Zemke
DTSTART;VALUE=DATE-TIME:20201005T190000Z
DTEND;VALUE=DATE-TIME:20201005T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/3
DESCRIPTION:Title: A
few refinements of Heegaard Floer genus and clasp number bounds\nby Ia
n Zemke as part of MIT Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Patrick Orson
DTSTART;VALUE=DATE-TIME:20201019T190000Z
DTEND;VALUE=DATE-TIME:20201019T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/5
DESCRIPTION:Title: To
pologically embedding spheres in knot traces\nby Patrick Orson as part
of MIT Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shaoyun Bai
DTSTART;VALUE=DATE-TIME:20201109T200000Z
DTEND;VALUE=DATE-TIME:20201109T210000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/6
DESCRIPTION:Title: Eq
uivariant Cerf theory and SU(n) Casson invariants\nby Shaoyun Bai as p
art of MIT Geometry and Topology Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aliakbar Daemi
DTSTART;VALUE=DATE-TIME:20201116T200000Z
DTEND;VALUE=DATE-TIME:20201116T210000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/7
DESCRIPTION:Title: Ch
ern-Simons functional\, singular instantons\, and the four-dimensional cla
sp number\nby Aliakbar Daemi as part of MIT Geometry and Topology Semi
nar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kouki Sato
DTSTART;VALUE=DATE-TIME:20201130T150000Z
DTEND;VALUE=DATE-TIME:20201130T160000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/8
DESCRIPTION:Title: Fi
ltered instanton Floer homology and the homology cobordism group\nby K
ouki Sato as part of MIT Geometry and Topology Seminar\n\n\nAbstract\nNote
the time change!\n\nWe introduce a family of real-valued homology cobordi
sm invariants r_s(Y) of oriented homology 3-spheres. The invariants r_s(Y)
are based on a quantitative construction of filtered instanton Floer homo
logy. Using our invariants\, we give several new constraints of the set of
smooth boundings of homology 3-spheres. As one of the corollaries\, we gi
ve infinitely many homology 3-spheres which cannot bound any definite 4-ma
nifold. As another corollary\, we show that if the 1-surgery of a knot has
negative Froyshov invariant\, then the 1/n-surgeries (n>0) of the knot ar
e linearly independent in the homology cobordism group. This is a joint wo
rk with Yuta Nozaki and Masaki Taniguchi.\n
LOCATION:https://researchseminars.org/talk/mitgt/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Markus Land
DTSTART;VALUE=DATE-TIME:20210222T200000Z
DTEND;VALUE=DATE-TIME:20210222T210000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/9
DESCRIPTION:Title: Co
bordism categories\, hermitian K-theory\, and (stable) cohomology of autom
orphism groups\nby Markus Land as part of MIT Geometry and Topology Se
minar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/mitgt/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Arun Debray
DTSTART;VALUE=DATE-TIME:20210301T200000Z
DTEND;VALUE=DATE-TIME:20210301T210000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/10
DESCRIPTION:Title: S
table diffeomorphism classification of some unorientable 4-manifolds\n
by Arun Debray as part of MIT Geometry and Topology Seminar\n\n\nAbstract\
nKreck's modified surgery theory provides a bordism-theoretic classificati
on of closed\, connected 4-manifolds up to stable diffeomorphism\, i.e. up
to diffeomorphism after connect-sum with some number of copies of S^2 x S
^2. For some classes of unorientable 4-manifolds with fundamental group pi
_1 finite of order 2 mod 4\, the classification question simplifies consid
erably\, reducing to the case where pi_1 = Z/2. In this talk\, I'll explai
n the generalities of Kreck's theorem and the ingredients that go into it\
, then specialize and give the classification in the case where pi_1 is fi
nite of order 2 mod 4. If time remains\, I'll discuss what changes when on
e asks about the stable homeomorphism classification of topological 4-mani
folds.\n
LOCATION:https://researchseminars.org/talk/mitgt/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Danica Kosanovic
DTSTART;VALUE=DATE-TIME:20210315T190000Z
DTEND;VALUE=DATE-TIME:20210315T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/11
DESCRIPTION:Title: K
notted families of arcs\nby Danica Kosanovic as part of MIT Geometry a
nd Topology Seminar\n\n\nAbstract\nGoodwillie and Weiss developed a powerf
ul homotopy theoretic technique for studying spaces of embeddings. For pro
perly embedded arcs in a manifold of any dimension these techniques can be
given a geometric flavour inspired by Vassiliev theory for classical knot
s. The outcome is a set of explicit nontrivial classes in homotopy groups
of spaces of arcs. I will give an overview of this story\, and also outlin
e how such computations can be applied to some open problems in 4-dimensio
nal topology. The latter is joint work with Peter Teichner.\n
LOCATION:https://researchseminars.org/talk/mitgt/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Slava Krushkal
DTSTART;VALUE=DATE-TIME:20210329T190000Z
DTEND;VALUE=DATE-TIME:20210329T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/13
DESCRIPTION:Title: F
illing links in 3-manifolds\nby Slava Krushkal as part of MIT Geometry
and Topology Seminar\n\nAbstract: TBA\n\nI will discuss the notion of fil
ling links in 3-manifolds: a link is filling if any 1-spine of the 3-manif
old\, disjoint from the link\, injects into the link complement on the lev
el of the fundamental group. I will give a construction of links in the 3-
torus which are filling modulo terms of the lower central series\; the pro
of relies on a new extension of the Stallings theorem. I will also discuss
the construction of Leininger and Reid of filling links and spines in 3-m
anifolds of rank 2\, and formulate some open problems. (Joint work with Mi
chael Freedman)\n
LOCATION:https://researchseminars.org/talk/mitgt/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Baldwin
DTSTART;VALUE=DATE-TIME:20210405T190000Z
DTEND;VALUE=DATE-TIME:20210405T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/14
DESCRIPTION:Title: I
nstanton L-spaces and splicing\nby John Baldwin as part of MIT Geometr
y and Topology Seminar\n\n\nAbstract\nWe prove that the 3-manifold obtaine
d by gluing the complements of two nontrivial knots in homology 3-sphere i
nstanton L-spaces\, by a map which identifies meridians with Seifert longi
tudes\, cannot be an instanton L-space. This recovers the recent theorem o
f Lidman-Pinzon-Caicedo-Zentner that the fundamental group of every closed
\, oriented\, toroidal 3-manifold admits a nontrivial SU(2)-representation
\, and consequently Zentner's earlier result that the fundamental group of
every closed\, oriented 3-manifold besides the 3-sphere admits a nontrivi
al SL(2\, C)-representation. This is joint work with Steven Sivek.\n
LOCATION:https://researchseminars.org/talk/mitgt/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anubhav Mukherjee
DTSTART;VALUE=DATE-TIME:20210412T190000Z
DTEND;VALUE=DATE-TIME:20210412T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/15
DESCRIPTION:Title: O
bstructions to embeddings in 4-manifolds using Bauer--Furuta type invarian
t\nby Anubhav Mukherjee as part of MIT Geometry and Topology Seminar\n
\n\nAbstract\nIn this talk I will discuss some new properties of an invari
ant for 4-manifold with boundary which was originally defined by Nobuo Iid
a. As one of the applications of this new invariant I will demonstrate how
one can obstruct a knot from being h-slice (i.e bound a homologically tri
vial disk) in 4-manifolds. Also\, this invariant can be useful to detect e
xotic smooth structures of 4-manifolds. This a joint work with Nobuo Iida
and Masaki Taniguchi.\n
LOCATION:https://researchseminars.org/talk/mitgt/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Kindred
DTSTART;VALUE=DATE-TIME:20210426T190000Z
DTEND;VALUE=DATE-TIME:20210426T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/16
DESCRIPTION:Title: R
eplumbing definite surfaces: the geometric content of the flyping theorem<
/a>\nby Thomas Kindred as part of MIT Geometry and Topology Seminar\n\n\nA
bstract\nIn 1898\, P.G. Tait asserted several properties of alternating li
nk diagrams\, which remained unproven until the discovery of the Jones pol
ynomial in 1985. By 1993\, the Jones polynomial had led to proofs of all o
f Tait's conjectures\, but the geometric content of these new results rema
ined mysterious.\n\nIn 2017\, Howie and Greene independently gave the firs
t geometric characterizations of alternating links\; as a corollary\, Gree
ne obtained the first purely geometric proof of part of Tait's conjectures
. Recently\, I used these characterizations and "replumbing" moves\, among
other techniques\, to give the first entirely geometric proof of Tait's f
lyping conjecture\, first proven in 1993 by Menasco and Thistlethwaite.\n\
nI will describe these recent developments\, focusing in particular on the
fundamentals of plumbing (also called Murasugi sum) and definite surfaces
(which characterize alternating links a la Greene). As an aside\, I will
use these two techniques to give a simple proof of the classical result of
Murasugi and Crowell that the genus of an alternating knot equals half th
e degree of its Alexander polynomial. The talk will be broadly accessible.
Expect lots of pictures!\n
LOCATION:https://researchseminars.org/talk/mitgt/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dave Gabai
DTSTART;VALUE=DATE-TIME:20210503T190000Z
DTEND;VALUE=DATE-TIME:20210503T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/17
DESCRIPTION:Title: K
notted 3-balls in the 4-sphere\nby Dave Gabai as part of MIT Geometry
and Topology Seminar\n\n\nAbstract\nWe give examples of codimension-1 knot
ting in the 4-sphere\, i.e. there are 3-balls B_1 with boundary the standa
rd 2-sphere\, which are not isotopic rel boundary to the standard 3-ball B
_0. In fact isotopy classes of such balls form a group which is infinitely
generated. The existence of knotted balls implies that there exists inequ
ivalent fiberings of the unknot in the 4-sphere\, in contrast to the situa
tion in dimension-3. Also\, that there exists diffeomorphisms of S^1 x B^3
homotopic rel boundary to the identity\, but not isotopic rel boundary to
the identity. (Joint work with Ryan Budney)\n
LOCATION:https://researchseminars.org/talk/mitgt/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:William Olsen
DTSTART;VALUE=DATE-TIME:20210510T190000Z
DTEND;VALUE=DATE-TIME:20210510T200000Z
DTSTAMP;VALUE=DATE-TIME:20240329T065848Z
UID:mitgt/18
DESCRIPTION:Title: T
risections and Ozsvath-Szabo cobordism maps\nby William Olsen as part
of MIT Geometry and Topology Seminar\n\n\nAbstract\nGiven a smooth\, orien
ted four-manifold X with connected boundary\, we'll demonstrate how to use
the data of a trisection (in particular\, its diagrammatic and fibration
structures) to compute the induced cobordism maps in Heegaard Floer homolo
gy.\n
LOCATION:https://researchseminars.org/talk/mitgt/18/
END:VEVENT
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