| DATE | SEMINAR | SPEAKER | TITLE |
| Fri. Sep 3 |
Topology/Geometry, 11:00-11:50 RH316 |
Jim Hebda | "Heterogeneous Riemannian Manifolds" Part I |
| Thu Sep 9 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings IX." |
| Fri. Sep 10 |
Topology/Geometry, 11:00-11:50 RH316 |
Jim Hebda | "Heterogeneous Riemannian Manifolds" Part II |
| Thu Sep 16 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings X." |
| Fri. Sep 17 |
Topology/Geometry, 11:00-11:50 RH316 |
Cancelled |
Cancelled |
| Thu Sep 23 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XI." |
| Fri. Sep 24 |
Topology/Geometry, 11:00-11:50 RH316 |
Cancelled |
Cancelled |
| Tue. Sep 28 |
Analysis Seminar 4:10 - 5:00 pm RH 222 |
Brad Currey |
"Admissibility for a class
of quasiregular representations" |
| Thu Sep 30 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Cancelled |
Cancelled |
| Fri. Oct 1 |
Topology/Geometry, 11:00-11:50 RH316 |
Dr Simrat Ghuman |
"Invariants on Graphs"
Part I |
| Abstract: In
this talk, we address a classical problem in low dimensional topology:
the classification of tamely embedded, finite, connected graphs in
the three-sphere up to ambient isotopy. In the case that the graph is
homeomorphic to a circle, our problem reduces to the embedding problem
for knots in the three-sphere. Our major result is the existence of a
unique isotopy class of longitudes of a cycle for an infinite class of
graphs. We then define new invariants for this infinite class of graphs.
First we define a longitude of a cycle in the graph. In contrast to the
situation of a knot, for a graph it is quite difficult to canonically select an isotopy class of longitudes. However we prove that longitudes exist for any cycle in any finite graph and are unique in certain situations. This definition of a longitude can be considered an extension of the definition of a longitude of a tamely embedded knot in the three-sphere. Next, in the situation in which the longitude for a cycle is unique, we define a sequence of invariants which detect whether this longitude lies in the n-th term of the lower central series of the fundamental group of the complement of the graph in the three-sphere. These invariants can be viewed as extensions of Milnor's invariants of a link. Although this invariant is not complete, we provide examples illustrating that this invariant is more sensitive than Milnor's invariant applied to a subgraph consisting of a link. |
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| Tue Oct 5 |
Analysis Seminar 4:10 - 5:00 pm RH 222 |
Brad Currey |
"Admissibility for a class of quasiregular representations" |
| Thu Oct 7 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XII." |
| Fri. Oct 8 |
Topology/Geometry, 11:00-11:50 RH316 |
Dr Simrat Ghuman |
"Invariants on Graphs" Part
II |
| Tue Oct 12 |
Analysis Seminar 4:10 - 5:00 pm RH 222 |
Brody Johnson |
"Characterizing orthonormality
of refinable functions via the transition operator." |
| Abstract: This
talk begins a survey of results due to Lawton, Lee, and Shen regarding the use of the transition operator to characterize the stability and orthonormality of multivariate refinable functions under the assumption of a finitely supported refinement mask. This characterization is useful for the construction of compactly supported multivariate orthonormal wavelets. |
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| Thu Oct 14 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XIII." |
| Fri. Oct 15 |
Topology/Geometry, 11:00-11:50 RH316 |
Dr Simrat
Ghuman |
"Invariants on Graphs" Part
III |
| Tue Oct 19 |
Analysis Seminar 4:10 - 5:00 pm RH 222 |
Brody Johnson |
"Characterizing orthonormality
of refinable functions via the transition operator." |
| Thu Oct 21 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XIV." |
| Fri. Oct 22 |
Topology/Geometry, 11:00-11:50 RH316 |
Steve Harris |
"When is the causal boundary
of spacetime Haussdorf?" |
| Tue Oct 26 |
Math and Computer Science
Club 3:45 pm in RH 237. |
Movie Night |
"Wargames" |
| Abstract: Come
join the Math and Computer Science Club for our movie night. Matthew Broderick and Ally Sheedy star in the 1983 movie "Wargames". In the movie a young Matthew Broderick statrs as a kid who hacks into the computer of a government agency, and this has disastrous consequences. You will be amazed by the technology used in this movie. So come and see "Wargames", you will have a ball. Pizza will be provided. Join us for fun, food and more at 3:45 pm in RH 237. |
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| Thu Oct 28 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XV." |
| Fri. Oct 29 |
Topology/Geometry, 11:00-11:50 RH316 |
Steve Harris |
"When is the causal boundary
of spacetime Haussdorf? II" |
| Thu Nov 4 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XVI." |
| Fri. Nov 5 |
Topology/Geometry, 11:00-11:50 RH316 |
Steve Harris |
"When is the causal boundary
of spacetime Haussdorf? III" |
| Fri. Nov 12 |
Topology/Geometry, 11:00-11:50 RH316 |
Anneke Bart |
"Deformations of Hyperbolic Manifolds" |
| Abstract: This
talk covers joint work with Kevin Scannell. I will give a general introduction
to deformations and infinitesimal deformations of Hyperbolic manifolds.
Some examples including the figure eight knot, a link (a subgroup of PSL(2,O7)),
and the Fibonacci knot will be discussed in detail. |
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| Thu Nov 18 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XVII." |
| Fri. Nov 19 |
Topology/Geometry, 11:00-11:50 RH316 |
Ryo Ohashi |
The classification of isometry groups
of a Seifert fibered space N which is double covered by a lens space L. |
| Abstract: Let
W be a twisted I-bundle over a Klein bottle fibered trivially whose base space
is a Mobius band and V be a (p,q)-fibered solid torus. Since the boundaries
of V and W are tori, we may form a quotient space N by identifying
the boundary tori. Let f : bd(V ) -> bd(W) denote the glueing
map. One can choose f to be a fiber preserving map.
Next, we let N = V \cup_{f} W be such the quotient space. As the attaching preserves the fiber, N is also a (p,q)-fibered Seifert fibered space, which is known as a prism manifold. We can observe that the base space of N is topologically a real projective plane that contains at most one cone point of order p. In the talk, we will carefully observe that N is double covered by a symmetric lens space L, which gives us a geometric structure on N. It turns out that L and Isom(N) are completely determined by the initial assignment of a fibration type on V. We will observe how a fibration type affects topological structures on N and L as well as Isom(N). Moreover, this allows us to compute the isometry group of N denoted by Isom(N). The technique to compute Isom(N) depends on the liftability criteria, that is, if h : L -> N is a covering map and if g \in Homeo(N), then there is \bar{g}: L \rightarrow L such that h \circ \bar{g} = g \circ h if and only if g_* \circ h_* (\pi_1(L)) is a subgroup of h_*(\pi_1(L)). Unfortunately, the liftability does not work in certain cases. Thus, Isom(N) was not able to classify completely in my last talk. In these cases, a "pullback" method will be used. In other words, we will use the fact that there is a subgroup in S^3 \oplus S^3 and an epimorphism \hat{\rho} such that image of the subgroup under \hat{\rho} is Isom(N). Further, the key ingredient to determine Isom(N) is as follows: If G_1 and G_2 are any finite non-cyclic subgroups of Isom_+(S^3) = SO(3) such that G_1 \cong G_2 and acting on S^3 freely, then the two groups are a difference of some conjugate. This will give us the complete classification of Isom(N). |
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| Tue Nov 28 |
Analysis Seminar 4:10 - 5:00 pm RH 222 |
Tom McNamara |
"Admissibility for unitary representations of the oscillator group" |
| Thu Dec 2 |
Algebra Seminar 2:10-3:00 p.m., RH 134 |
Greg Marks |
"Duo power series rings XVIII." |
| Fri. Dec 3 |
Topology/Geometry, 11:00-11:50 RH316 |
Ryo Ohashi |
The classification of isometry
groups of a Seifert fibered space N which is double covered by a lens space
L. |