| Talk_id | Date | Speaker | Title |
|
4112
|
Wednesday 9/6
4:10 PM
|
Ustun Yildirim, MSU
|
Complexified Cayley Grassmannian
- Complexified Cayley Grassmannian
- 09/06/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Ustun Yildirim, MSU
No abstract available.
|
|
4103
|
Thursday 9/7
11:00 AM
|
Erik Bates, Stanford University
|
Low-temperature localization of directed polymers
- Low-temperature localization of directed polymers
- 09/07/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Erik Bates, Stanford University
On the d-dimensional integer lattice, directed polymers can be seen as paths of a random walk in random environment, except that the environment updates at each time step. The result is a statistical mechanical system, whose qualitative behavior is governed by a temperature parameter and the law of the environment. Historically, the phase transitions of this system have been best understood by whether or not the path’s endpoint localizes. While the endpoint is no longer a Markov process as in a random walk, its quenched distribution is. The key difficulty is that the space of measures is too large for one to expect convergence results. By adapting methods recently used by Mukherjee and Varadhan, we develop a compactification theory to resolve the issue. In this talk, we will discuss this intriguing abstraction, as well as new concrete theorems it allows us to prove for directed polymers constructed from SRW or any other walk. (This talk is based on joint work with Sourav Chatterjee.)
|
|
4073
|
Thursday 9/7
2:00 PM
|
Mark Greenfield, University of Michigan
|
Thurston's metric on Teichmueller spaces of flat n-tori
- Thurston's metric on Teichmueller spaces of flat n-tori
- 09/07/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Mark Greenfield, University of Michigan
Several interesting metrics have been defined for Teichmueller spaces of hyperbolic surfaces. However, analogous metrics on the Teichmueller space of flat n-tori have not been as well studied. After reviewing some background on Teichmueller theory, we will define an analog of Thurston's metric for these spaces. We find that in dimension n=2, it agrees with the hyperbolic metric. In particular, this gives a new way to realize the hyperbolic plane as the moduli space of marked flat tori. Time permitting, we will describe the corresponding situation in dimension n>2. This work is joint with Lizhen Ji.
|
|
4111
|
Thursday 9/7
4:10 PM
|
MSU Postdocs
|
Postdoc Lightning Talks
- Postdoc Lightning Talks
- 09/07/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- MSU Postdocs
No abstract available.
|
|
4113
|
Friday 9/8
3:00 PM
|
Robert J. Rietz, MAAA
|
Actuarial Kickoff Lecture
- Actuarial Kickoff Lecture
- 09/08/2017
- 3:00 PM - 4:30 PM
- B117 Wells Hall
- Robert J. Rietz, MAAA
"Effects of Gainsharing Provisions on the Selection of a
Discount Rate for a Defined Benefit Pension Plan
|
|
4119
|
Monday 9/11
3:00 PM
|
Charlotte Ure, MSU
|
The Burnside Problem and PI-Theory
- The Burnside Problem and PI-Theory
- 09/11/2017
- 3:00 PM - 3:50 PM
- C304 Wells Hall
- Charlotte Ure, MSU
No abstract available.
|
|
4107
|
Monday 9/11
4:10 PM
|
Katherine Raoux, MSU
|
τ-invariants for knots in rational homology spheres
- τ-invariants for knots in rational homology spheres
- 09/11/2017
- 4:10 PM - 5:30 PM
- C304 Wells Hall
- Katherine Raoux, MSU
Using the knot filtration on the Heegaard Floer chain complex, Ozsváth and Szabó defined an invariant of knots in the 3-sphere called τ(K). In particular, they showed that τ(K) is a lower bound for the 4-ball genus of K. Generalizing their construction, I will show that for a (not necessarily null-homologous) knot, K, in a rational homology sphere, Y, we can define a collection of τ-invariants, one for each spin-c structure on Y. In addition, these invariants give a lower bound for the genus of a surface with boundary K properly embedded in a negative definite 4-manifold with boundary Y.
|
|
4117
|
Tuesday 9/12
11:00 AM
|
|
Reading seminar on Topological Insulators
- Reading seminar on Topological Insulators
- 09/12/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
-
In the study of quantum phases, the concept of topological invariant has emerged as a new paradigm beyond that of Landau theory. The relevance of topology for the classification of phases has been known since the discovery of the quantum hall effect. However, recent theoretical and experimental discoveries of new topological insulators has led to a renewed interest. The purpose of this reading group is to explore both recent and classical results for topological insulators including but not limited to (1) bulk-boundary correspondence (2) K-theoretic classification of topological insulators (3) topological invariants in the presence of disorder (4) quantization of Hall conductance in interacting systems.
|
|
4114
|
Tuesday 9/12
4:10 PM
|
Bruce Sagan, Michigan State University
|
Bounding Roots of Polynomials
- Bounding Roots of Polynomials
- 09/12/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Bruce Sagan, Michigan State University
We will present methods for bounding the modulus of the complex roots of a polynomial. These include the Cauchy bound and the use of Newton polynomials, the latter also being useful in interpolation problems. No background outside of elementary calculus will be assumed. In a subsequent talk, we will use these techniques to make progress on a conjecture about the roots of a polynomial of combinatorial interest.
|
|
4104
|
Thursday 9/14
11:00 AM
|
Matthew Cha, MSU
|
Stability of superselection sectors in infinite quantum spin systems
- Stability of superselection sectors in infinite quantum spin systems
- 09/14/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Matthew Cha, MSU
Superselection sectors are equivalence classes of unitarily equivalent representations and can be used to label charges in a quantum system. We consider a family of superselection sectors for infinite quantum spin systems corresponding to almost localized endomorphisms. If the vacuum state is pure and satisfies certain locality conditions, we show how to recover the charge statistics. In particular, the superselection structure is that of a braided tensor category, and further, is stable against deformations by a quasi-local dynamics. We apply our results to prove stability of anyons in Kitaev's quantum double. Braided tensor categories naturally appear as the algebraic theory of anyons in topological phases of matter. Our results provide evidence that the anyonic structure is an invariant of topologically ordered states. This is work is joint with Pieter Naaijkens and Bruno Nachtergaele.
|
|
4102
|
Thursday 9/14
2:00 PM
|
Diana Hubbard, University of Michigan
|
On the braid index and the fractional Dehn twist coefficient
- On the braid index and the fractional Dehn twist coefficient
- 09/14/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Diana Hubbard, University of Michigan
The braid index of a knot is the least number of strands necessary to represent the knot as a closure of a braid on that many strands. If we view a braid as an element of the mapping class group of the punctured disk, its fractional Dehn twist coefficient (FDTC) is a number that measures the amount of twisting it exerts about the boundary of the disk. In this talk I will demonstrate that n-braids with FDTC larger than n-1 realize the braid index of their closure. The proof uses the concordance homomorphism Upsilon arising from knot Floer homology as a crucial tool. This is joint work with Peter Feller.
|
|
4121
|
Thursday 9/14
4:10 PM
|
Raluca Balan, University of Ottawa
|
Second order Lyapunov exponent for the hyperbolic Anderson model
- Second order Lyapunov exponent for the hyperbolic Anderson model
- 09/14/2017
- 4:10 PM - 5:00 PM
- C405 Wells Hall
- Raluca Balan, University of Ottawa
In this talk, I will present some recent results regarding the asymptotic behavior of the second moment of the solution to the hyperbolic Anderson model in arbitrary spatial dimension d, driven by a Gaussian noise which is white in time. Two cases are considered for the spatial covariance structure of the noise: (i) the Fourier transform of the spectral measure of the noise is a non-negative locally-integrable function; (ii) d=1 and the noise is a fractional Brownian motion in space with index 1/4<H<1/2. These results are derived from a connection between the hyperbolic and parabolic models, and the recent powerful results of Huang, Le and Nualart (2015) for the parabolic model. This talk is based on joint work with Jian Song (University of Hong Kong).
|
|
4108
|
Thursday 9/14
4:10 PM
|
Rayan Saab, UCSD
|
Phase retrieval from local measurements
- Phase retrieval from local measurements
- 09/14/2017
- 4:10 PM - 5:00 PM
- C517 Wells Hall
- Rayan Saab, UCSD
We consider an instance of the phase-retrieval problem, where one wishes to recover a signal (viewed as a vector) from the noisy magnitudes of its inner products with locally supported vectors. Such measurements arise, for example, in ptychography, which is an imaging technique used in lense-less X-ray microscopes and in optical microscopes with increased fields of view.
Starting with the setup where the signal is one-dimensional, we present theoretical and numerical results on an approach that has two important properties. First, it allows deterministic measurement constructions (which we give examples of). Second, it uses a robust, fast recovery algorithm that consists of solving a system of linear equations in a lied space, followed by finding an eigenvector (e.g., via an inverse power iteration). We also present extensions to the two-dimensional setting.
This is joint work with M. Iwen, B. Preskit, and A. Viswanathan.
|
|
4091
|
Thursday 9/14
4:10 PM
|
Jason Starr, Stony Brook University
|
Solving polynomials with (higher) positive curvature
- Solving polynomials with (higher) positive curvature
- 09/14/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Jason Starr, Stony Brook University
A smooth solution set of a system of complex polynomials is a manifold that can be studied geometrically. About 15 years ago, two results proved the existence of solutions of the system over a "function field of a complex curve" (Graber-Harris-Starr) and over a finite field (Esnault) provided the associated complex manifolds have positive curvature in a weak sense (rational connectedness). More recently, when
the manifold satisfies a higher version of positive curvature (rational simple connectedness), a similar result was proved over a function field of a complex surface (de Jong-He-Starr). I will explain these results, some applications to algebra (Serre's "Conjecture II", "Period-Index"), and recent extensions, joint with Chenyang Xu, to "function fields over finite fields" and Ax's "PAC fields".
|
|
4128
|
Monday 9/18
3:00 PM
|
Nicholas Ovenhouse, MSU
|
Groupoids and Groupoid Objects
- Groupoids and Groupoid Objects
- 09/18/2017
- 3:00 PM - 3:50 PM
- C304 Wells Hall
- Nicholas Ovenhouse, MSU
The concept of a groupoid is a very general one, abstracting and generalizing many different concepts and definitions, including groups, group actions, equivalence relations, vector bundles, fundamental groups, and many others. I will define groupoids and give many examples, and then discuss the notion of "groupoid objects" in a category, which is the analogue of the notion of a "group object". Examples include Lie groupoids, symplectic groupoids, and algebraic groupoids.
|
|
4127
|
Monday 9/18
4:10 PM
|
Katherine Raoux, MSU
|
τ-invariants for knots in rational homology spheres (2)
- τ-invariants for knots in rational homology spheres (2)
- 09/18/2017
- 4:10 PM - 5:30 PM
- C304 Wells Hall
- Katherine Raoux, MSU
Using the knot filtration on the Heegaard Floer chain complex, Ozsváth and Szabó defined an invariant of knots in the 3-sphere called τ(K). In particular, they showed that τ(K) is a lower bound for the 4-ball genus of K. Generalizing their construction, I will show that for a (not necessarily null-homologous) knot, K, in a rational homology sphere, Y, we can define a collection of τ-invariants, one for each spin-c structure on Y. In addition, these invariants give a lower bound for the genus of a surface with boundary K properly embedded in a negative definite 4-manifold with boundary Y.
|
|
5133
|
Tuesday 9/19
11:00 AM
|
Matthew Cha
|
Reading seminar on Topological Insulators
- Reading seminar on Topological Insulators
- 09/19/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Matthew Cha
In the study of quantum phases, the concept of topological invariant has emerged as a new paradigm beyond that of Landau theory. The relevance of topology for the classification of phases has been known since the discovery of the quantum hall effect. However, recent theoretical and experimental discoveries of new topological insulators has led to a renewed interest. The purpose of this reading group is to explore both recent and classical results for topological insulators including but not limited to (1) bulk-boundary correspondence (2) K-theoretic classification of topological insulators (3) topological invariants in the presence of disorder (4) quantization of Hall conductance in interacting systems.
|
|
4123
|
Tuesday 9/19
4:10 PM
|
Bruce Sagan, Michigan State University
|
Roots of descent polynomials
- Roots of descent polynomials
- 09/19/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Bruce Sagan, Michigan State University
Let S_n be the symmetric group of all permutations p = p_1 ... p_n of the numbers 1, ..., n. The descent set of p is the set of indices i such that p_i > p_{i+1}. Given a set of positive integers I we let d(I;n) be the number of permutations in S_n with descent set I. In 1915 MacMahon proved that d(I;n) is a polynomial in n, but its properties do not seem to have been much studied until now. We apply the method of Newton bases from the previous lecture to make progress on a conjecture about the location of the roots of d(I;n) where n is now a complex number. This is joint work with Alexander Diaz-Lopez, Pamela Harris, Erik Insko, and Mohamed Omar.
|
|
5132
|
Wednesday 9/20
4:10 PM
|
Wenzhao Chen, MSU
|
Introduction to Casson-Gordon invariants
- Introduction to Casson-Gordon invariants
- 09/20/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Wenzhao Chen, MSU
This is an introductory talk on why and how Casson and Gordon defined Casson-Gordon invariants, based on their paper "Cobordism of classical knots".
|
|
5130
|
Thursday 9/21
10:00 AM
|
Eric Bucher, MSU
|
What is a cluster algebra?
- What is a cluster algebra?
- 09/21/2017
- 10:00 AM - 10:50 AM
- C304 Wells Hall
- Eric Bucher, MSU
This will be the first talk of the fall cluster algebra seminar. We have some new attendees this semester so we will start with the basics, discussing definitions and examples of cluster algebras.
|
|
4096
|
Thursday 9/21
11:00 AM
|
Gang Zhou, SUNY Binghamton
|
On the quantum and PDE models of Polaron
- On the quantum and PDE models of Polaron
- 09/21/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Gang Zhou, SUNY Binghamton
Polaron theory is a model of an electron in a crystal lattice.
It is studied in the framework of nonequilibrium statistic mechanics.
There are two different mathematical models: H. Frohlich proposed a
quantum model in 1937; L. Landau and S. I. Pekar proposed a system of
nonlinear PDEs in 1948. In this talk I will present a proof that these
two models are equivalent to certain orders, and present some other
related works. These are joint works with Rupert Frank.
|
|
4089
|
Thursday 9/21
2:00 PM
|
Adam Jacob, UC Davis
|
The deformed Hermitian-Yang-Mills equation
- The deformed Hermitian-Yang-Mills equation
- 09/21/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Adam Jacob, UC Davis
In this talk I will discuss a complex generalization of the special Lagrangian graph equation of Harvey-Lawson. I will discuss methods for constructing solutions, and relate the solvability of the equation with notions of stability from symplectic and algebraic geometry. This is joint work with T.C. Collins and S.-T. Yau.
|
|
4122
|
Thursday 9/21
3:00 PM
|
Dapeng Zhan, MSU
|
Parametrized SLE curves with self-similarity and stationary increments
- Parametrized SLE curves with self-similarity and stationary increments
- 09/21/2017
- 3:00 PM - 3:50 PM
- C405 Wells Hall
- Dapeng Zhan, MSU
We describe an SLE$_\kappa$ curve, $\kappa\in(0,8)$, which is parametrized by $(d:=1+\frac \kappa 8)$-dimensional Minkowski content, and has self-similarity of exponent $1/d$ and stationary increments. We then prove that such SLE$_\kappa$ curve is $\alpha$-H\"older continuous for any $\alpha<1/d$, and Mckean's dimension theorem holds for this curve.
|
|
5134
|
Friday 9/22
4:00 PM
|
Rodrigo Bezerra Matos, MSU
|
Introduction to ergodic Schrodinger operators I
- Introduction to ergodic Schrodinger operators I
- 09/22/2017
- 4:00 PM - 5:00 PM
- C117 Wells Hall
- Rodrigo Bezerra Matos, MSU
This is the first introductory talk of the reading seminar. The main goals are to show that spectra of ergodic operators are almost surely invariant, and to introduce several important objects such as the integrated density of states.
|
|
4090
|
Monday 9/25
4:10 PM
|
Tye Lidman, NCSU
|
Band surgeries between knots
- Band surgeries between knots
- 09/25/2017
- 4:10 PM - 5:30 PM
- C304 Wells Hall
- Tye Lidman, NCSU
Attaching a half-twisted band to a knot produces a non-orientable cobordism to a new knot. The knots which admit such band moves to the unknots are quite simple - they are all cabled knots. We characterize when there exists such a band move between other families of knots. This is joint work with Allison Moore.
|
|
5137
|
Tuesday 9/26
4:10 PM
|
Robert Davis, MSU
|
A Combinatorial Description of Schur Functions
- A Combinatorial Description of Schur Functions
- 09/26/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Robert Davis, MSU
A symmetric function is a formal power series in countably many variables that is fixed under any permutation of the indices of the variables. The set of symmetric functions forms a vector space (actually, a graded algebra), and so it is natural to look for convenient bases of the space. In this talk, we will describe four "easy" bases and one more subtle, but much more important, basis, called the basis of Schur functions. We will give the combinatorial definition of Schur functions and highlight some of its uses in various branches of mathematics.
|
|
4097
|
Thursday 9/28
11:00 AM
|
Günter Stolz, University of Alabama Birmingham
|
Localization in the droplet spectrum of the random XXZ spin chain
- Localization in the droplet spectrum of the random XXZ spin chain
- 09/28/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Günter Stolz, University of Alabama Birmingham
The XXZ quantum spin chain in random exterior field is one of the models where numerics indicate the existence of a many-body localization transition. We will discuss recent joint work with Alexander Elgart and Abel Klein, which provides rigorous results on the localization side of the expected transition. We show several of the accepted manifestations of MBL at the bottom of the spectrum for the random XXZ chain in the Ising phase. In this regime spins form quasi-particles in the form of droplets (of, say, down-spins in a sea of up-spins), which become fully localized under the addition of a random field.
|
|
4105
|
Thursday 9/28
2:00 PM
|
Renaud Detcherry, MSU
|
Turaev Viro invariants and Gromov norm
- Turaev Viro invariants and Gromov norm
- 09/28/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Renaud Detcherry, MSU
According to Chen and Yang's volume conjecture, the asymptotics of the Turaev-Viro invariants of a 3-manifold predicts its hyperbolic volume. We show a compatibility between Turaev-Viro invariants and JSJ-decomposition and get an ineqality relating Turaev-Viro invariants and Gromov norm.
|
|
4106
|
Thursday 9/28
4:10 PM
|
Günter Stolz, University of Alabama Birmingham
|
What is many-body localization?
- What is many-body localization?
- 09/28/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Günter Stolz, University of Alabama Birmingham
The phenomenon of many-body localization (MBL), as opposed to one-particle or Anderson localization, has recently received strong attention in the physics and quantum information literature. We will discuss the difference between these two concepts and then propose disordered quantum spin systems as a suitable model to study MBL. Among the possible manifestations of MBL we will mention the absence of many-body (or information) transport as well as area laws for the quantum entanglement of eigenstates. Examples where these properties can be proven include the random XY chain and, more recently, the droplet regime of the random XXZ chain. But many problems remain open.
|
|
4118
|
Monday 10/2
4:10 PM
|
Thomas Walpuski, MSU
|
Counting associatives and Seiberg-Witten equations
- Counting associatives and Seiberg-Witten equations
- 10/02/2017
- 4:10 PM - 5:30 PM
- C304 Wells Hall
- Thomas Walpuski, MSU
There is a natural functional on the space of orientation 3-dimensional submanifolds in a G2-manifold. Its critical points are associative submanifolds, a special class of volume-minimizing submanifolds which obey an elliptic deformation theory. Given this, it is a natural question whether one can count associative submanifolds in order to construct an enumerative invariant for G2–manifolds. I will explain several geometric scenarios, which prohibit a naive count of such submanifolds cannot possible be invariant. I will then go on to discuss how (generalized) Seiberg-Witten equations might help cure these problems.
|
|
4099
|
Tuesday 10/3
11:00 AM
|
Akos Nagy, Fields Institute/University of Waterloo
|
BPS monopoles with non-maximal symmetry breaking and the Nahm transform
- BPS monopoles with non-maximal symmetry breaking and the Nahm transform
- 10/03/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Akos Nagy, Fields Institute/University of Waterloo
The notion of “broken symmetry” is central in gauge theories. For BPS monopoles, symmetry breaking can be defined in terms of the eigenvalues of the Higgs-field at infinity. The symmetry breaking is maximal if the eigenvalues are distinct. Monopoles with maximal symmetry breaking have been studied extensively by both mathematicians and physicists for decades now, but little is known about the general case.
In this talk, I will show how to produce monopoles with arbitrary symmetry breaking using the Nahm transform, and I will also outline the construction of its inverse. The inversion heavily uses first order elliptic PDE's on non-compact spaces, more concretely, the theory of Callias-type operators in 3D.
This is a joint project with Benoit Charbonneau.
|
|
5138
|
Tuesday 10/3
4:10 PM
|
Robert Davis, MSU
|
Follow the Rules!
- Follow the Rules!
- 10/03/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Robert Davis, MSU
Schur functions are among the most useful bases for symmetric functions, but they come at the cost of making certain computations much less obvious than when done in other bases. In particular, how can we determine the coefficients of a product of Schur functions in the basis of Schur functions? There are many equivalent ways to computing these numbers; this talk will discuss jeu de taqin, which is an equivalence among skew tableaux, and apply it to obtain a formulation of the Littlewood-Richardson rule, which answers our question. If time allows, we will discuss other important formulations of this rule.
|
|
4125
|
Wednesday 10/4
4:10 PM
|
Demetrios Christodoulou, ETH Zurich
|
The Development of Shocks in Compressible Fluids
- The Development of Shocks in Compressible Fluids
- 10/04/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Demetrios Christodoulou, ETH Zurich
The lecture shall trace the history of the theoretical study of the formation and evolution of shocks in compressible fluids, starting with the fundamental work of Riemann, the first work on nonlinear hyperbolic partial differential equations. Riemann considered the case of plane symmetry where the problem reduces to 1 spatial dimension. One milestone in the development of the theory was the work of Sideris who gave the first general proof of the finite time breakdown of smooth solutions in 3 spatial dimensions. Another milestone was the work of Majda who first addressed the problem of the local in time continuation of a shock front as a nonlinear free boundary problem for a nonlinear hyperbolic system of partial differential equations. I shall then discuss my own work, which uses differential geometric methods and resolves the resulting singularities giving a complete description in terms of smooth functions.
My first work studies the maximal smooth development of given smooth initial data, the boundary of the domain of this development, and the behavior of the solution at this boundary. The boundary contains certain singular hypersurfaces which originate from certain singular surfaces. The singular surfaces do occur in nature, but not the singular hypersurfaces. My second work studies the physical evolution beyond the singular surfaces by solving a nonlinear free boundary problem with singular initial conditions associated to each of the singular surfaces. From each singular surface a shock hypersurface issues which appears as the corresponding free boundary.
|
|
4124
|
Thursday 10/5
2:00 PM
|
Thomas Walpuski, MSU
|
Wall-crossing for the Seiberg-Witten equation with two spinors
- Wall-crossing for the Seiberg-Witten equation with two spinors
- 10/05/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Thomas Walpuski, MSU
Unlike for the classical Seiberg-Witten equation, compactness fails for the Seiberg-Witten equation with multiple spinors. This non-compactness is caused by Fueter sections with values in the moduli space of charge 1 SU(n) ASD instantons. In the simplest case, n = 2, those are Z/2 harmonic spinors. In this talk I will explain in more detail what the preceding sentences mean and then discuss the wall-crossing caused by the appearance of (non-singular) Z/2 harmonic spinors.
This is joint work with Aleksander Doan.
|
|
4092
|
Thursday 10/5
4:10 PM
|
Björn Sandstede, Brown University
|
TBA
- TBA
- 10/05/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Björn Sandstede, Brown University
No abstract available.
|
|
5136
|
Tuesday 10/10
1:30 PM
|
|
Mathematics Education Colloquium
- Mathematics Education Colloquium
- 10/10/2017
- 1:30 PM - 3:00 PM
- 252 EH
-
Title: Students’ graphing activities: Re-presentations of what?
Abstract:
Students’ representational activities are key to their mathematical development. Specifically, students’ representational activities in constructing displayed graphs can afford them the figurative material necessary to engage in and abstract mental operations. In this talk, I draw on Piagetian ideas to frame the sophistication of students’ ways of thinking for graphing. Namely, I illustrate distinctions between those ways of thinking dominated by sensorimotor experience and those ways of thinking dominated by the coordination of mental actions. Against the backdrop of these distinctions, I argue that we, as educators and researchers, need to broaden students’ representational experiences. Instructionally, doing so can afford students increased opportunities to construct productive and generative ways of thinking for mathematical ideas and concepts. In terms of research, broadening students’ representational experiences enables researchers to form more viable and detailed working hypotheses of students’ ways of thinking for graphing and related topics.
|
|
5135
|
Wednesday 10/11
4:10 PM
|
Tyler Bongers, MSU
|
TBA
- TBA
- 10/11/2017
- 4:10 PM - 5:00 PM
- C517 Wells Hall
- Tyler Bongers, MSU
No abstract available.
|
|
4098
|
Thursday 10/12
11:00 AM
|
Otis Chodosh
|
TBA
- TBA
- 10/12/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Otis Chodosh
No abstract available.
|
|
4093
|
Thursday 10/12
4:10 PM
|
Frank Sottile, Texas A&M University
|
TBA
- TBA
- 10/12/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Frank Sottile, Texas A&M University
No abstract available.
|
|
4115
|
Thursday 10/19
2:00 PM
|
Elmas Irmak, Bowling Green State University
|
seminar
- seminar
- 10/19/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Elmas Irmak, Bowling Green State University
No abstract available.
|
|
4129
|
Thursday 10/19
4:10 PM
|
Laura DeMarco, Northwestern University
|
Complex dynamics and elliptic curves
- Complex dynamics and elliptic curves
- 10/19/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Laura DeMarco, Northwestern University
In this talk, I will present some connections between recent research in dynamical systems and the classical theory of elliptic curves and rational points. The main goal is to explain the role of dynamical stability and bifurcations in deducing arithmetic finiteness statements. I will focus on three examples: (1) the theorem of Mordell and Weil from the 1920s, presented from a dynamical point of view; (2) a recent result of Masser and Zannier about torsion points on elliptic curves, and (3) features of the Mandelbrot set.
|
|
5139
|
Friday 10/20
4:10 PM
|
Laura DeMarco, Northwestern University
|
The Mandelbrot set: what we know today
- The Mandelbrot set: what we know today
- 10/20/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Laura DeMarco, Northwestern University
The Mandelbrot set is one of the most famous objects in modern mathematics. We see images of it everywhere, but despite its popularity and decades of research, we still don't fully understand it. I will survey results about the Mandelbrot set, from its discovery to today.
|
|
4094
|
Thursday 10/26
4:10 PM
|
|
TBA
- TBA
- 10/26/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
-
No abstract available.
|
|
4100
|
Thursday 11/2
11:00 AM
|
Marius Lemm, IAS
|
TBA
- TBA
- 11/02/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Marius Lemm, IAS
No abstract available.
|
|
5128
|
Thursday 11/2
2:00 PM
|
|
Meera Mainkar
- Meera Mainkar
- 11/02/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
-
TBA
|
|
4109
|
Friday 11/10
4:10 PM
|
Ben Schmidt, Mathematics, MSU
|
TBA
- TBA
- 11/10/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Ben Schmidt, Mathematics, MSU
No abstract available.
|
|
4120
|
Thursday 11/16
2:00 PM
|
Elizabeth Munch, MSU
|
TBA
- TBA
- 11/16/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- Elizabeth Munch, MSU
No abstract available.
|
|
5131
|
Thursday 11/23
2:00 PM
|
|
Thanksgiving---No seminar
- Thanksgiving---No seminar
- 11/23/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
-
No abstract available.
|
|
5129
|
Thursday 11/30
2:00 PM
|
J.D. Quigley, University of Notre Dame
|
TBA
- TBA
- 11/30/2017
- 2:00 PM - 3:00 PM
- C304 Wells Hall
- J.D. Quigley, University of Notre Dame
No abstract available.
|
|
4110
|
Friday 12/1
4:10 PM
|
Rajesh Kulkarni, Mathematics, MSU
|
TBA
- TBA
- 12/01/2017
- 4:10 PM - 5:00 PM
- C304 Wells Hall
- Rajesh Kulkarni, Mathematics, MSU
No abstract available.
|
|
4101
|
Thursday 12/7
11:00 AM
|
Jake Fillman, Virginia Tech
|
TBA
- TBA
- 12/07/2017
- 11:00 AM - 12:00 PM
- C304 Wells Hall
- Jake Fillman, Virginia Tech
No abstract available.
|
