Spectral Theory Brown Bag Seminar



Fall 2014

  • Wednesday, August 27, 2014
    Jake Fillman
    Spectral Theory of Discrete Limit-Periodic Schrödinger Operators
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 3, 2014
    William Yessen
    Overview of the Spectral Theory of One-Dimensional Substitution Hamiltonians
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 10, 2014
    William Yessen
    Some Open Problems and Research Directions in One-Dimensional Substitution Hamiltonians
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 17, 2014
    Jake Fillman
    Spectral Homogeneity for Limit Periodic Schrödinger Operators
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 24, 2014
    Jake Fillman
    Spectral Homogeneity for Limit Periodic Schrödinger Operators II
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, October 1, 2014
    Tom VandenBoom
    TBA
    12:00 – 1:00 p.m.  //  HB 427  



Spring 2014

  • Friday, January 31, 2014
    William Yessen
    Quantum Information Transport in One-Dimensional Spin-1/2 Chains
    12:00 – 1:00 p.m.  //  HB 427  

  • Monday, April 21, 2014
    Milivoje Lukic
    Ballistic Motion for Periodic Jacobi Matrices and Periodic Block-Jacobi Matrices
    12:00 – 1:00 p.m.  //  HB 453  



Fall 2013

  • Thursday, August 29, 2013
    Darren Ong
    Existence of Embedded Eigenvalues for Decaying Oscillatory Perturbations of Periodic Schrödinger Operators
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, September 5, 2013
    Jake Fillman
    On the Existence of Bound States for Discrete Schrödinger Operators
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, September 12, 2013
    Milivoje Lukic
    Limit-Periodic Schrödinger Operators with Uniformly Localized Eigenfunctions
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, September 26, 2013
    William Yessen
    On the OPUC-Ising Duality
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, October 3, 2013
    Darren Ong
    Uniformly Singular Continuous Spectrum for the Period Doubling Hamiltonian
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, October 10, 2013
    Paul Munger
    Hölder Continuity of the Density of States for a Class of Quasiperiodic Schrödinger Operators
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, October 31, 2013
    Milivoje Lukic
    On Higher-Order Szego Theorems With a Single Critical Point of Arbitrary Order
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, November 7, 2013
    Darren Ong
    CMV Operators Generated by the Period Doubling Subshift
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, November 14, 2013
    Jake Fillman
    Coulombic Perturbations of the Free CMV Matrix I: Zero-Dimensionality of the Singular Part
    12:10 – 12:55 p.m.  //  HB 423  

  • Thursday, November 21, 2013
    Jake Fillman
    Coulombic Perturbations of the Free CMV Matrix II: Absence of Singular Continuous Spectrum
    12:10 – 12:55 p.m.  //  HB 423  



Spring 2012

  • Wednesday, January 11, 2012
    William Yessen
    Spectral Analysis of Tridiagonal Fibonacci Hamiltonians: Recent Results, Open Problems and Conjectures
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, January 25, 2012
    Darren Ong
    Continuity of the Lyapunov Exponent for Quasiperiodic Operators with Analytic Potential
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, February 1, 2012
    Milivoje Lukic
    The Critical Almost Mathieu Operator
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, February 8, 2012
    Jake Fillman
    Dynamical Analysis of Schrödinger Operators with Growing Sparse Potentials
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, February 15, 2012
    Milivoje Lukic
    Duality and Singular Continuous Spectrum in the Almost Mathieu Equation
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, February 22, 2012
    Darren Ong
    U(1,1)
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, March 7, 2012
    Darren Ong
    Periodic Approximation of Quasiperiodic Schrödinger Cocycles with Analytic Potential
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, March 28, 2012
    Milivoje Lukic
    Bounds on Embedded Singular Spectrum for One-Dimensional Schrödinger Operators
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, April 18, 2012
    Paul Munger
    The Fibonacci CMV Operator
    12:00 – 1:00 p.m.  //  HB 427  

  • Monday, April 23, 2012
    Helge Krüger
    The Skew-Shift Model
    2:00 – 4:00 p.m.  //  HB 427  



Fall 2011

  • Wednesday, August 24, 2011
    Darren Ong
    Limit-Periodic Verblunsky Coefficients for OPUC
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 7, 2011
    Sergey Belov
    The Kunz-Souillard Approach to Localization
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, September 14, 2011
    Jake Fillman
    Spectrum and Generalized Eigenfunctions
    12:00 – 1:00 p.m.  //  HB 427  

  • Friday, September 23, 2011
    Sergey Belov
    An Introduction to OPUC
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, October 5, 2011
    David Damanik
    The Discovery of Quasicrystals: Shechtman Wins Chemistry Nobel Prize
    12:00 – 1:00 p.m.  //  HB 427  

  • Friday, October 7, 2011
    Darren Ong
    OPUC Potpourri I
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, October 12, 2011
    Darren Ong
    OPUC Potpourri II
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, October 26, 2011
    David Damanik
    Hassell's Proof of Quantum Non-Unique Ergodicity for the Bunimovich Stadium
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, November 2, 2011
    Milivoje Lukic
    Variational Estimates for Discrete Schrödinger Operators with Potentials of Indefinite Sign
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, November 16, 2011
    Jake Fillman
    The Magic Formula
    12:00 – 1:00 p.m.  //  HB 427  

  • Wednesday, November 30, 2011
    Paul Munger
    OPUC with Fibonacci Verblunsky Coefficients
    4:00 – 5:00 p.m.  //  HB 227  

  • Wednesday, December 7, 2011
    Milivoje Lukic
    Kotani Theory
    12:00 – 1:00 p.m.  //  HB 427  

  • Monday, December 12, 2011
    Anton Gorodetski
    Spectrum of the Fibonacci Hamiltonian as a Dynamically Defined Cantor Set
    10:00 – 11:00 a.m.  //  HB 427  



Spring 2011

  • Monday, January 31, 2011
    Darren Ong
    Spectral Properties of Limit-Periodic Schrödinger Operators
    12:00 – 1:00 p.m.  //  HB 423  

  • Monday, February 7, 2011
    Darren Ong
    Spectral Properties of Limit-Periodic Schrödinger Operators II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, February 9, 2011
    Sergey Belov
    WKB Approximations of Regge Poles
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, February 16, 2011
    Zheng Gan
    Profinite Groups and Limit-Periodic Sequences
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, March 9, 2011
    Paul Munger
    Spectra of Quasiperiodic Schrödinger Operators
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, March 16, 2011
    Paul Munger
    Spectra of Quasiperiodic Schrödinger Operators II
    5:00 – 6:00 p.m.  //  HB 423  

  • Wednesday, March 23, 2011
    Darren Ong
    Almost Periodic Functions
    5:00 – 6:00 p.m.  //  HB 423  

  • Wednesday, March 30, 2011
    Darren Ong
    Almost Periodic Functions II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 6, 2011
    Zheng Gan
    Profinite Groups and Limit-Periodic Sequences II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 13, 2011
    Paul Munger
    Almost Periodic Functions III
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 20, 2011
    Darren Ong
    Jitomirskaya-Last for OPUC
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 27, 2011
    Darren Ong
    Jitomirskaya-Last for OPUC II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, May 4, 2011
    Paul Munger
    Estimating the Hausdorff Dimension of the Spectrum of a Quasiperiodic Schrödinger Operator
    1:00 – 2:00 p.m.  //  HB 423  



Fall 2010

  • Wednesday, August 25, 2010
    Zheng Gan
    Brownian Motion, Heat Equation and Ito Integral
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, September 1, 2010
    Darren Ong
    Stochastic Verblunsky Coefficients
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, September 8, 2010
    Jon Chaika
    An Introduction to Non-Uniquely Ergodic Interval Exchange Transformations
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, September 15, 2010
    Robert Vance
    Periodic Points in Affine Interval Exchange Transformations
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, September 22, 2010
    Sergey Belov
    Orthogonal Polynomials and Riemann-Hilbert Problems
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, October 6, 2010
    Darren Ong
    Lyapunov Exponents in OPUC
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, October 13, 2010
    Darren Ong
    The Ruelle-Oseledets Theorem
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, October 27, 2010
    Darren Ong
    Kotani Theory
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, November 3, 2010
    Robert Vance
    Density of the Ergodic Measure for Rauzy-Veech Induction
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, November 10, 2010
    Sevak Mkrtchyan
    Limit Shapes of Random Young Diagrams With Respect to Schur-Weyl Measures
    5:00 – 6:00 p.m.  //  HB 227  

  • Wednesday, November 17, 2010
    Darren Ong
    The Spectrum and Lyapunov Exponent of Limit-Periodic Schrödinger Operators
    5:00 – 6:00 p.m.  //  HB 227  



Spring 2010

  • Wednesday, February 17, 2010
    Helge Krüger
    The Skew-Shift at Small Coupling
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, February 24, 2010
    Janine Dahl
    The Dimension of the Spectrum of the Off-Diagonal Fibonacci Hamiltonian II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, March 10, 2010
    Jon Fickenscher
    Every Rauzy Class Contains A Self-Inverse Permutation
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, March 24, 2010
    Zheng Gan
    Discontinuity of Lyapunov Exponents
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, March 31, 2010
    Darren Ong
    On Geronimus' Theorem
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 21, 2010
    Sergey Belov
    Parameter Dependence in Riemann-Hilbert Problems with Application to Semiclassical Focusing NLS
    12:00 – 1:00 p.m.  //  HB 423  

  • Monday, April 26, 2010
    Darren Ong
    Multiplication by z in OPUC
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 28, 2010
    Helge Krüger
    The Combes-Thomas Estimate
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, April 30, 2010
    Helge Krüger
    Multi-Scale Analysis
    12:00 – 1:00 p.m.  //  HB 423  



Fall 2009

  • Wednesday, September 2, 2009
    Helge Krüger
    Regularity = Vanishing of the Lyapunov Exponent on the Spectrum
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, September 9, 2009
    Jon Chaika
    Every Transformation is Disjoint From Almost Every IET
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, September 16, 2009
    Sergey Belov
    Long-Time Asymptotics of the Nonlinear Schrödinger Equation Shock Problem
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, September 23, 2009
    Zheng Gan
    Limit-Periodic Schrödinger Operators with Pure Point Spectrum
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, September 30, 2009
    Helge Krüger
    Semiclassical Results for Gaps in the Spectrum of the Almost Mathieu Operator
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, October 14, 2009
    Jon Fickenscher
    The Simplicity of the Lyapunov Spectrum for Rauzy Monoids
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, October 21, 2009
    Jon Fickenscher
    The Simplicity of the Lyapunov Spectrum for Rauzy Monoids II
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, October 28, 2009
    Sergey Belov
    Determinant Form of the Complex Phase Function of the Steepest Descent Analysis of Riemann-Hilbert Problems and its Application to the Focusing Nonlinear Schrödinger Equation
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, November 11, 2009
    Zheng Gan
    Limit-Periodic Schrödinger Operators with Pure Point Spectrum II
    12:00 – 1:00 p.m.  //  HB 423  



Spring 2009

  • Friday, January 23, 2009
    Helge Krüger
    On the Integrated Density of States
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, January 30, 2009
    Jon Chaika
    Borel-Cantelli Sequences and Shrinking Target Properties
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, February 20, 2009
    Janine Dahl
    Hyperbolic Dynamics
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, February 25, 2009
    Helge Krüger
    Dvir's Proof of Wolff's Finite Field Kakeya Conjecture
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, March 13, 2009
    Zheng Gan
    Spectrum of Limit Periodic Schrödinger Operators - Positive Lyapunov Exponents and Zero Hausdorff Dimension
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, March 27, 2009
    Helge Krüger
    Multiscale Analysis for Ergodic Schrödinger Operators and Positivity of Lyapunov Exponents for Potentials Given by High-Dimensional Skew-Shifts at Small Coupling
    12:00 – 1:00 p.m.  //  HB 423  

  • Wednesday, April 1, 2009
    Zheng Gan
    Limit Periodic Schrödinger Operators in the Regime of Positive Lyapunov Exponents II
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, April 10, 2009
    Jon Fickenscher
    Weak Mixing for Interval Exchange Transformations and Translation Flows
    12:00 – 1:00 p.m.  //  HB 423  

  • Friday, April 17, 2009
    Jon Chaika
    A Brief Introduction to Ergodic Theory
    12:00 – 1:00 p.m.  //  HB 423  



Fall 2008

  • Wednesday, September 3, 2008
    Helge Krüger
    Approximating Discrete Schrödinger Operators by Finite Sections
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, September 10, 2008
    Jon Chaika
    An Introduction to Continued Fractions
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, September 17, 2008
    David Damanik
    The Survival Probability in Quantum Dynamics
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, October 1, 2008
    Helge Krüger
    An Introduction to Quasi-Periodic Localization
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, October 8, 2008
    Zheng Gan
    Quantum Dynamics and Decompositions of Singular Continuous Spectra
    12:30 – 1:30 p.m.  //  HB 423  

  • Friday, October 17, 2008
    Sergey Belov
    Riemann-Hilbert Problems
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, October 22, 2008
    Sergey Belov
    Inverse Scattering for Cubic NLS Through RH Problems
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, November 5, 2008
    Jon Fickenscher
    A Question About Fundamental Regions For Fuchsian Groups
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, November 12, 2008
    David Damanik
    Coefficient Stripping and Sum Rules for Jacobi Matrices
    12:30 – 1:30 p.m.  //  HB 423  

  • Wednesday, December 3, 2008
    Janine Dahl
    The Dimension of the Spectrum of the Off-Diagonal Fibonacci Hamiltonian
    12:30 – 1:30 p.m.  //  HB 423